JP2014012831A - Coolant composition and method of operating internal combustion engine using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coolant composition which can improve fuel consumption efficiency of an internal combustion engine, and a method of operating an internal combustion engine using the coolant composition.SOLUTION: A coolant composition contains a nonionic surfactant serving as a viscometric property modifier and a base. The kinematic viscosity of the coolant composition is 8.5 mm/s or more at 25°C, and 2.0 mm/s or less at 100°C.

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 at temperatures below 0 ° C and increases in volume, which may damage the engine and radiator. 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, the viscosity has been lowered to improve 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, and therefore, even when a liquid agent containing such a viscosity index improver is used as a cooling liquid, the cooling loss at low temperatures is reduced, In addition, the cooling capacity at high temperatures cannot be maintained.

  Patent Document 7 discloses a coolant composition containing water and a surfactant having a cloud point, wherein the content of the surfactant is 25 to 70% by weight based on the composition. Products, and polyoxyethylene polyoxypropylene alkyl ethers as surfactants. According to Patent Document 7, a cooling liquid having high cooling performance and antifreezing property can be obtained without adding glycols by adding the above surfactant as a freezing point depressant to water at a predetermined ratio. Providing a composition is described. However, Patent Document 7 does not describe improving the fuel efficiency of the internal combustion engine by adjusting the kinematic viscosity of the coolant composition.

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 JP 2010-270256 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 present inventors have added a nonionic surfactant as a viscosity property improver to make the kinematic viscosity of the coolant composition in a specific range, thereby reducing cooling loss at low temperatures and at high temperatures. It has been found that the cooling capacity can be maintained, and therefore the fuel efficiency of the internal combustion engine is greatly improved.

(式中、
Ｒ^１は、炭素数７以上の炭化水素基であり、
ｎは、３〜１０の整数である）
で表される化合物及び下記式（２）：

(式中、
Ｒ^２は、炭素数７以上の炭化水素基であり、
ａ及びｂは正の整数であり、
ａとｂとの和は、３０〜３００の整数である）
で表される化合物から選択される少なくとも１種である、上記（３）に記載の冷却液組成物。
（８）式（１）の化合物及び式（２）の化合物を含む、上記（７）に記載の冷却液組成物。
（９）ポリオキシエチレン脂肪酸アミドを、組成物１００質量部に対して、０．７５〜１８質量部含有する、上記（７）又は（８）に記載の冷却液組成物。
（１０）上記（１）〜（９）のいずれかに記載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。
（１１）上記（１）〜（９）のいずれかに記載の冷却液組成物を得るための濃縮組成物。 That is, the present invention includes the following inventions.
(1) contains a nonionic surfactant and a base as a viscosity property improver,
The base contains at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols and glycol monoalkyl ethers,
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 viscosity characteristic improver is at least one selected from the group consisting of a compound having a polyethylene glycol chain, an ethylene glycol fatty acid ester, a propylene glycol fatty acid ester, a glycerin fatty acid ester, a polyglycerin fatty acid ester, and a fatty acid alkanolamide. The coolant composition according to (1) above.
(3) The coolant composition according to (1) or (2) above, wherein the viscosity characteristic improver is a compound having a polyethylene glycol chain.
(4) The viscosity property improver is polyoxyethylene polyoxypropylene glycol, polyoxyethylene monoalkyl ether, polyoxyethylene dialkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, polyethylene glycol monofatty acid Ester, polyethylene glycol difatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil and polyoxyethylene fatty acid amide The coolant composition according to (3), which is at least one selected from the group consisting of:
(5) The above (1) or (2), wherein the viscosity characteristic improver is at least one selected from the group consisting of ethylene glycol fatty acid ester, propylene glycol fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester and fatty acid alkanolamide. The coolant composition as described in).
(6) The coolant composition according to any one of (1) to (5), wherein the viscosity characteristic improver is contained in an amount of 0.15 to 28 parts by mass with respect to 100 parts by mass of the composition.
(7) The viscosity characteristic improver is a polyoxyethylene fatty acid amide, and the polyoxyethylene fatty acid amide is represented by the following formula (1):

(Where
R ¹ is a hydrocarbon group having 7 or more carbon atoms,
n is an integer of 3 to 10)
And a compound represented by the following formula (2):

(Where
R ² is a hydrocarbon group having 7 or more carbon atoms,
a and b are positive integers;
(The sum of a and b is an integer of 30 to 300)
The coolant composition according to (3) above, which is at least one selected from the compounds represented by:
(8) The coolant composition according to (7) above, comprising the compound of formula (1) and the compound of formula (2).
(9) The coolant composition according to (7) or (8), wherein the polyoxyethylene fatty acid amide is contained in an amount of 0.75 to 18 parts by mass with respect to 100 parts by mass of the composition.
(10) A method for operating an internal combustion engine, wherein the coolant composition according to any one of (1) to (9) is used as a coolant for the internal combustion engine.
(11) A concentrated composition for obtaining the coolant composition according to any one of (1) to (9) above.

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

  The cooling liquid composition of the present invention contains a nonionic surfactant as a viscosity characteristic 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 nonionic surfactant is not particularly limited as long as the kinematic viscosity of the coolant composition can be within a desired range, but a compound having a polyethylene glycol chain can be used. Examples of the compound having a polyethylene glycol chain include, but are not limited to, polyethylene glycol, polyhydric alcohols such as propylene glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and the like added with ethylene oxide. . Another alkylene glycol chain such as a propylene glycol chain or a butylene glycol chain may be bonded to the polyethylene glycol chain. This combination may be block or random. Specifically, polyoxyethylene polyoxypropylene glycol, polyoxyethylene monoalkyl ether, polyoxyethylene dialkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, polyethylene glycol monofatty acid ester, polyethylene glycol Examples include difatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, and polyoxyethylene fatty acid amides. In polyoxyethylene polyoxypropylene glycol, polyoxyethylene monoalkyl ether, poly Polyoxyethylene dialkyl ethers, polyethylene glycol mono fatty acid esters, polyethylene glycol di-fatty acid esters Preferably, polyoxyethylene dialkyl ethers, polyethylene glycol di-fatty acid esters, polyoxyethylene polyoxypropylene glycol and polyethylene glycol mono-fatty acid esters are particularly preferred. These can be used alone or in combination of two or more.

  The nonionic surfactant is not particularly limited as long as the kinematic viscosity of the coolant composition can be within a desired range, but ethylene glycol fatty acid ester, propylene glycol fatty acid ester, glycerin fatty acid ester, polyglycerin. At least one selected from the group consisting of fatty acid esters and fatty acid alkanolamides can be used.

  The blending amount of the viscosity property improving agent is not particularly limited as long as the kinematic viscosity of the cooling composition at a low temperature and a high temperature can be within the predetermined range, and is 0.1% relative to 100 parts by mass of the composition. It is preferable that it is 15-28 mass parts, and it is especially preferable that it is 0.2-25 mass parts. 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. It is preferable that the compounding quantity of a base is 62-99.75 mass parts with respect to 100 mass parts of compositions, and it is especially preferable that it is 67-97.85 mass parts.

  Examples of the base include at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols, and glycol monoalkyl ethers.

  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 6.2 to 98.75 parts by mass, and 15.5 to 98.75 parts by mass with respect to 100 parts by mass of the composition in consideration of antifreezing properties. Is particularly preferred.

  The base may contain water, and the water is preferably ion-exchanged water. The blending amount of water is preferably 0.62 to 89.78 parts by mass, particularly preferably 0.62 to 74.8 parts by mass with respect to 100 parts by mass of the composition. 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, particularly preferably 40:60 to 75:25, from the viewpoint of avoiding the flash point. .

(式中、
Ｒ^１は、炭素数７以上の炭化水素基であり、
ｎは、３〜１０の整数である）
で表される化合物及び下記式（２）：

(式中、
Ｒ^２は、炭素数７以上の炭化水素基であり、
ａ及びｂは正の整数であり、
ａとｂとの和は、３０〜３００の整数である）
で表される化合物から選択される少なくとも１種を挙げることができる。 In the cooling composition of the present invention, the viscosity property improver is preferably a polyoxyethylene fatty acid amide. As polyoxyethylene fatty acid amide, the following formula (1):

(Where
R ¹ is a hydrocarbon group having 7 or more carbon atoms,
n is an integer of 3 to 10)
And a compound represented by the following formula (2):

(Where
R ² is a hydrocarbon group having 7 or more carbon atoms,
a and b are positive integers;
(The sum of a and b is an integer of 30 to 300)
The at least 1 sort (s) selected from the compound represented by these can be mentioned.

In the above formula (1), the hydrocarbon group represented by R ¹ usually has 7 or more carbon atoms, preferably 13 to 17 carbon atoms. The hydrocarbon group represented by R ¹ may be a linear, branched, or saturated or unsaturated hydrocarbon group, and is preferably a linear saturated hydrocarbon group. Specific examples of the hydrocarbon group represented by R ¹ include, for example, 1-methylhexyl group, n-heptyl group, isoheptyl group, 1,1,3,3-tetramethylbutyl group, 1-methylheptyl group, 3- Methylheptyl group, n-octyl group, 2-ethylhexyl group, 1,1,3-trimethylhexyl group, 1,1,3,3-tetramethylpentyl group, nonyl group, decyl group, undecyl group, 1-methylun A decyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, a hardened beef tallow alkyl group, and a coconut oil alkyl group are exemplified, and a hardened beef tallow alkyl group is particularly preferable. The compound represented by Formula (1) can be used individually or in combination of 2 or more types.

  In the above formula (1), n is an integer of 3 to 10, preferably 4 to 7.

  Specific examples of the compound represented by the above formula (1) include commercially available products such as Esomeide HT / 15 (manufactured by Lion Corporation).

In the above formula (2), the hydrocarbon group represented by R ² usually has 7 or more carbon atoms, preferably 7 to 21 carbon atoms, and more preferably 17 to 21 carbon atoms. The hydrocarbon group represented by R ² may be a linear, branched, or saturated or unsaturated hydrocarbon group, and is preferably a linear saturated hydrocarbon group. Specific examples of the hydrocarbon group represented by R ² include, for example, 1-methylhexyl group, n-heptyl group, isoheptyl group, 1,1,3,3-tetramethylbutyl group, 1-methylheptyl group, 3- Methylheptyl group, n-octyl group, 2-ethylhexyl group, 1,1,3-trimethylhexyl group, 1,1,3,3-tetramethylpentyl group, nonyl group, decyl group, undecyl group, 1-methylun Decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, hardened beef tallow alkyl group, coconut oil alkyl group, especially heptadecyl group preferable. The compound represented by Formula (2) can be used individually or in combination of 2 or more types.

  In the above formula (2), a and b are positive integers, and the sum of a and b is an integer of 30 to 300, preferably 50 to 300.

  Specific examples of the compound represented by the above formula (2) include commercially available products such as BROWNON SD-50 (manufactured by Aoki Oil & Fat Co., Ltd.).

  Any of the compound represented by the above formula (1) and the compound represented by the above formula (2) may be used alone, or both may be used. The total amount is not particularly limited as long as the kinematic viscosity of the cooling composition at the low temperature and the high temperature can be within the predetermined range, and is 0.75 to 18 with respect to 100 parts by mass of the composition. It is preferable that it is a mass part.

  When the compound represented by the above formula (1) is used alone, the blending amount is 0.75 to 10 parts by mass with respect to 100 parts by mass of the composition from the viewpoint of securing practical fluidity at low temperatures. It is preferable that it is 0.8 to 6 parts by mass. When the compound represented by the above formula (2) is used alone, the blending amount thereof is preferably 8 to 18 parts by mass, particularly 10 to 16 parts by mass with respect to 100 parts by mass of the composition. preferable.

  When using both the compound represented by the said Formula (1) and the compound represented by the said Formula (2), the sum total of the compounding quantity is 0.82-15 mass parts with respect to 100 mass parts of compositions. It is preferable that it is 0.96 to 8 parts by mass. The compounding ratio of the compound represented by the above formula (1) and the compound represented by the above formula (2) is preferably 2: 1 to 10: 1, particularly preferably 3: 1 to 5: 1. is there. In particular, when both the compound represented by the above formula (1) and the compound represented by the above formula (2) are used, a synergistic effect can be expected with respect to the thermal characteristics of the cooling composition by using the above compounding ratio. . Further, from the viewpoint of obtaining a synergistic effect on thermal characteristics, it is preferable to combine a compound represented by the formula (1) and a compound represented by the formula (2) with a high and low HLB value. Any of the compound represented by the formula (1) and the compound represented by the formula (2) may be used as one having a high HLB value and one having a low HLB value. For example, it is preferable to combine a compound represented by the formula (1) and a compound represented by the formula (2) having an HLB of less than 16 and a compound having a HLB of 16 or more. It is particularly preferred to combine certain things.

  In the cooling composition of the present invention, if necessary, other additives can be blended with the base as long as the effects of the present invention are not impaired, in addition to the above-described viscosity characteristic 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. Examples of rust preventives include phosphoric acid and / or salts thereof, aliphatic carboxylic acids 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 present invention also relates to a concentrated composition for obtaining the coolant composition. The concentrated composition of the present invention is a composition containing 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 1-3 and Comparative Example 1-6
[Example 1]
47 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 1 part by mass of polyethylene glycol monofatty acid ester to the obtained mixed liquid, the mixed liquid was heated to 80 ° C., then stirred for 30 minutes, stirred and cooled to obtain a cooling liquid composition.

[Example 2]
In the same manner as in Example 1 except that 23 parts by mass of ethylene glycol was used instead of 47 parts by mass of ethylene glycol and 25 parts by mass of polyethylene glycol monofatty acid ester was used instead of 1 part by mass of polyethylene glycol monofatty acid ester. A coolant composition was obtained.

[Example 3]
Example, except that 47.8 parts by mass of ethylene glycol was used instead of 47 parts by mass of ethylene glycol, and 0.2 parts by mass of polyoxyethylene polyoxypropylene glycol was used instead of 1 part by mass of polyethylene glycol monofatty acid ester 1 was used to obtain a coolant composition.

[Comparative Example 1]
A coolant composition was obtained in the same manner as in Example 1 except that 48 parts by mass of ethylene glycol was used instead of 47 parts by mass of ethylene glycol, and polyethylene glycol monofatty acid ester was not used. The coolant composition of Comparative Example 1 corresponds to a conventional 50% ethylene glycol coolant, and was used as a reference when evaluating warm-up performance and cooling performance.

[Comparative Example 2]
47.8 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. To the obtained liquid mixture, 0.2 part by weight of carboxyvinyl polymer was added and dissolved at room temperature, and then neutralized with potassium hydroxide to obtain a cooling liquid composition. The coolant composition of Comparative Example 2 corresponds to a coolant with improved warm-up performance obtained by adding a thickener to a conventional 50% ethylene glycol coolant.

[Comparative Example 3]
A coolant composition was obtained in the same manner as in Example 1 except that 1 part by mass of polyethylene glycol was used instead of 1 part by mass of polyethylene glycol monofatty acid ester. The coolant composition of Comparative Example 3 corresponds to a coolant with improved warm-up performance in which a thickener is added to a conventional 50% ethylene glycol coolant.

[Comparative Example 4]
A coolant composition was obtained in the same manner as in Example 1 except that ethylene glycol and polyethylene glycol monofatty acid ester were not used and 98 parts by mass of ion-exchanged water was used instead of 50 parts by mass of ion-exchanged water. The cooling liquid composition of Comparative Example 4 corresponds to a conventional cooling liquid having water as a base and high cooling performance.

[Comparative Example 5]
Example, except that 47.9 parts by mass of ethylene glycol was used instead of 47 parts by mass of ethylene glycol, and 0.1 parts by mass of polyoxyethylene polyoxypropylene glycol was used instead of 1 part by mass of polyethylene glycol monofatty acid ester 1 was used to obtain a coolant composition.

[Comparative Example 6]
In the same manner as in Example 1, except that 18 parts by mass of ethylene glycol was used instead of 47 parts by mass of ethylene glycol, and 30 parts by mass of polyethylene glycol monofatty acid ester was used instead of 1 part by mass of polyethylene glycol monofatty acid ester. A coolant composition was obtained.

  The kinematic viscosity at 25 ° C. and 100 ° C. of the cooling compositions obtained in Example 1-3 and Comparative Example 1-6 was 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 cooling 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 having a measurement time of 200 seconds or longer, 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 1 (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 at room temperature of 25 ° C. (see FIG. 1), and the time until the aluminum casting was cooled from 90 ° C. to 80 ° C. was measured. The result of Comparative Example 1 (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 1-3 and Comparative Example 1-6.

  From Table 1, the coolant composition of Example 1-3 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. In particular, Example 2 shows that the warm-up performance is further improved than the coolant compositions of Comparative Examples 2 and 3 in which the conventional warm-up performance is improved.

  It can be seen that the cooling liquid compositions of Comparative Examples 2, 3, and 6 have high warm-up performance, but are inferior in cooling performance because of a small decrease in kinematic viscosity at high temperatures. On the other hand, the cooling liquid composition of Comparative Example 4 has high cooling performance, but has a low kinematic viscosity at low temperatures and is inferior in warm-up performance.

  It can be seen that the coolant composition of Comparative Example 5 does not have an effect as a viscosity characteristic improver because the content of the nonionic surfactant is not sufficient.

Example 4-15 and Comparative Example 7-10
[Example 4]
47.2 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 0.8 parts by mass of polyoxyethylene (5) cured beef tallow amide (Lion Corporation, Esomide HT / 15) to the obtained mixed liquid, the temperature of the mixed liquid was raised to 80 ° C., and then 30 minutes The mixture was stirred and cooled with stirring to obtain a cooling liquid composition.

[Example 5]
A coolant composition was obtained in the same manner as in Example 4 except that 47.1 parts by mass of ethylene glycol and 0.9 parts by mass of polyoxyethylene (5) -cured beef tallow amide were used.

[Example 6]
A coolant composition was obtained in the same manner as in Example 4 except that 46.5 parts by mass of ethylene glycol was used and 1.5 parts by mass of polyoxyethylene (5) -cured beef tallow amide was used.

[Example 7]
A coolant composition was obtained in the same manner as in Example 4 except that 46 parts by mass of ethylene glycol was used and 2 parts by mass of polyoxyethylene (5) -cured beef tallow amide was used.

[Example 8]
A coolant composition was obtained in the same manner as in Example 4 except that 45 parts by mass of ethylene glycol was used and 3 parts by mass of polyoxyethylene (5) -cured beef tallow amide was used.

[Example 9]
A coolant composition was obtained in the same manner as in Example 4 except that 44 parts by mass of ethylene glycol was used and 4 parts by mass of polyoxyethylene (5) -cured beef tallow amide was used.

[Example 10]
Except for using 38 parts by mass of ethylene glycol and using 10 parts by mass of polyoxyethylene (50) stearamide (Brownon SD-50, manufactured by Aoki Oil & Fat Co., Ltd.) instead of polyoxyethylene (5) cured beef tallow amide Obtained a coolant composition in the same manner as in Example 4.

[Example 11]
Coolant composition in the same manner as in Example 4 except that 34 parts by mass of ethylene glycol was used and 14 parts by mass of polyoxyethylene (50) stearamide was used instead of polyoxyethylene (5) cured beef tallow amide I got a thing.

[Example 12]
Coolant composition in the same manner as in Example 4 except that 32 parts by mass of ethylene glycol was used and 16 parts by mass of polyoxyethylene (50) stearamide was used instead of polyoxyethylene (5) cured beef tallow amide I got a thing.

[Example 13]
Using 45.6 parts by mass of ethylene glycol, 2 parts by mass of polyoxyethylene (5) -cured beef tallow amide and 0.4 parts by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is 75 ° C. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to.

[Example 14]
Using 45.5 parts by mass of ethylene glycol, 2 parts by mass of polyoxyethylene (5) hardened beef tallow amide and 0.5 parts by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is 75 ° C. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to.

[Example 15]
Using 45.3 parts by mass of ethylene glycol, 2 parts by mass of polyoxyethylene (5) hardened beef tallow amide and 0.7 parts by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is 75 ° C. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to.

[Example 16]
Using 45 parts by mass of ethylene glycol, 2 parts by mass of polyoxyethylene (5) cured beef tallow amide and 1 part by mass of polyoxyethylene (50) stearamide were added in this order, and the mixture was heated to 75 ° C. Except for the above, a coolant composition was obtained in the same manner as in Example 4.

[Example 17]
Using 46.2 parts by mass of ethylene glycol, 1.5 parts by mass of polyoxyethylene (5) -cured beef tallow amide and 0.3 parts by mass of polyoxyethylene (50) stearamide are added in this order to prepare a mixed solution. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to 75 ° C.

[Example 18]
Using 46.1 parts by mass of ethylene glycol, 1.5 parts by mass of polyoxyethylene (5) -cured beef tallow amide and 0.4 parts by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is prepared. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to 75 ° C.

[Example 19]
Using 46 parts by mass of ethylene glycol, 1.5 parts by mass of polyoxyethylene (5) hardened beef tallow amide and 0.5 parts by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is 75 ° C. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to.

[Example 20]
Using 45.8 parts by mass of ethylene glycol, 1.5 parts by mass of polyoxyethylene (5) -cured beef tallow amide and 0.7 parts by mass of polyoxyethylene (50) stearamide are added in this order. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to 75 ° C.

[Example 21]
Using 46.9 parts by mass of ethylene glycol, 0.9 part by mass of polyoxyethylene (5) -cured beef tallow amide and 0.2 part by mass of polyoxyethylene (50) stearamide are added in this order, and the mixture is prepared. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to 75 ° C.

[Example 22]
Using 46.8 parts by mass of ethylene glycol, 0.9 part by mass of polyoxyethylene (5) -cured beef tallow amide and 0.3 part by mass of polyoxyethylene (50) stearamide are added in this order to prepare a mixed solution. A coolant composition was obtained in the same manner as in Example 4 except that the temperature was raised to 75 ° C.

[Comparative Example 7]
A coolant composition was obtained in the same manner as in Example 4 except that 47.3 parts by mass of ethylene glycol and 0.7 parts by mass of polyoxyethylene (5) -cured beef tallow amide were used.

[Comparative Example 8]
The coolant composition was the same as in Example 4 except that 28 parts by mass of ethylene glycol was used and 20 parts by mass of polyoxyethylene (50) stearamide was used instead of polyoxyethylene (5) cured beef tallow amide. I got a thing.

[Comparative Example 9]
The same method as in Example 4 except that 47.5 parts by mass of ethylene glycol was used and 0.5 parts by mass of polyoxyethylene (50) stearamide was used instead of polyoxyethylene (5) cured beef tallow amide. A coolant composition was obtained.

[Comparative Example 10]
The same method as in Example 4 except that 47.7 parts by mass of ethylene glycol was used and 0.3 parts by mass of polyoxyethylene (50) stearamide was used instead of polyoxyethylene (5) cured beef tallow amide. A coolant composition was obtained.

  The kinematic viscosity at 25 ° C. and 100 ° C. and the thermal characteristics (warming-up performance and cooling performance) of the cooling compositions obtained in Example 4-22 and Comparative Examples 1 and 7-10 were evaluated by the methods described above.

  Table 1 shows the measurement results of the kinematic viscosity, warm-up performance, and cooling performance of the coolant compositions of Example 4-22 and Comparative Examples 1 and 7-10.

  From Table 2, the coolant composition of Example 4-22 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.

By comparing Comparative Example 1 and Comparative Example 9, when 0.5 part by mass of polyoxyethylene (50) stearamide corresponding to the compound of formula (2) was used alone, It can be seen that the effect of improving kinematic viscosity at a low temperature is not obtained (while maintaining 3 mm ² / s), and the heating performance is not improved. However, the coolant composition of Example 6 containing 1.5 parts by mass of polyoxyethylene (5) -cured beef tallow amide has a kinematic viscosity at a low temperature of 44 mm ² / s and a warming performance of 0.9. On the other hand, the coolant composition of Example 19 in which 0.5 parts by mass of polyoxyethylene (50) stearamide was added thereto had a kinematic viscosity at a low temperature of 52 mm ² / s and the kinematic viscosity increased more than expected. The heating performance was further improved to 0.8. Thus, it was found that the combined use of polyoxyethylene (5) beef tallow amide and polyoxyethylene (50) stearamide increased the kinematic viscosity at a lower temperature than expected, and a synergistic effect was obtained. The same applies to the coolant composition of Example 22 (see Example 5 and Comparative Examples 1 and 10).

  It can be seen that the coolant composition of Comparative Example 7 does not have an effect as a viscosity characteristic improver because the polyoxyethylene fatty acid amide content is not sufficient. It can be seen that the cooling liquid composition of Comparative Example 8 has a low content of polyoxyethylene fatty acid amide and is poor in cooling performance because of a small decrease in kinematic viscosity at high temperatures.

  The coolant composition of the present invention is suitably used for cooling internal combustion engines, particularly automobile engines, inverters and batteries.

Claims (11)

Containing nonionic surfactants and bases as viscosity property improvers,
The base contains at least one alcohol selected from the group consisting of monohydric alcohols, dihydric alcohols, trihydric alcohols and glycol monoalkyl ethers,
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.   The viscosity property improver is at least one selected from the group consisting of a compound having a polyethylene glycol chain, an ethylene glycol fatty acid ester, a propylene glycol fatty acid ester, a glycerin fatty acid ester, a polyglycerin fatty acid ester, and a fatty acid alkanolamide. A coolant composition according to 1.   The coolant composition according to claim 1 or 2, wherein the viscosity characteristic improver is a compound having a polyethylene glycol chain.   Viscosity improvers are polyoxyethylene polyoxypropylene glycol, polyoxyethylene monoalkyl ether, polyoxyethylene dialkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol mono fatty acid ester, polyethylene Selected from the group consisting of glycol difatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil and polyoxyethylene fatty acid amide The coolant composition according to claim 3, which is at least one kind.   The coolant according to claim 1 or 2, wherein the viscosity characteristic improver is at least one selected from the group consisting of ethylene glycol fatty acid ester, propylene glycol fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, and fatty acid alkanolamide. Composition.   The coolant composition according to any one of claims 1 to 5, wherein the viscosity characteristic improver is contained in an amount of 0.15 to 28 parts by mass with respect to 100 parts by mass of the composition. The viscosity characteristic improver is a polyoxyethylene fatty acid amide, and the polyoxyethylene fatty acid amide is represented by the following formula (1):

(Where
R ¹ is a hydrocarbon group having 7 or more carbon atoms,
n is an integer of 3 to 10)
And a compound represented by the following formula (2):

(Where
R ² is a hydrocarbon group having 7 or more carbon atoms,
a and b are positive integers;
(The sum of a and b is an integer of 30 to 300)
The cooling fluid composition according to claim 3, which is at least one selected from the compounds represented by:   The coolant composition according to claim 7, comprising a compound of formula (1) and a compound of formula (2).   The coolant composition according to claim 7 or 8, comprising 0.75 to 18 parts by mass of polyoxyethylene fatty acid amide with respect to 100 parts by mass of the composition.   The operating method of an internal combustion engine using the cooling fluid composition in any one of Claims 1-9 as a cooling fluid of an internal combustion engine.   The concentrated composition for obtaining the cooling fluid composition of any one of Claims 1-9.

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