JP6208620B2 - 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 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, but the viscosity index improver described therein is fluid at low temperatures. It is formulated for the purpose of reducing the viscosity drop at high temperature while maintaining the temperature. 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.

  Patent Document 7 discloses a coolant composition containing water and a surfactant having a cloud point, and 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 specify a kinematic viscosity of a coolant composition by adding a viscosity property improver comprising at least one selected from betaine and an ionic substance and at least one anionic surfactant. It has been found that by setting the range, it is possible to reduce the cooling loss at low temperatures and maintain the cooling capacity at high temperatures, and thus the fuel efficiency effect of the internal combustion engine is greatly improved.
That is, the present invention includes the following inventions.

（式中、Ｒ_１はＣ_８〜Ｃ_１８のアルキル基である）
又は下記式（２）で表される化合物：

（式中、Ｒ_２はＣ_７〜Ｃ_１７のアルキル基である）
を含み、
イオン性物質が下記式（３）で表される化合物：

（式中、Ｒ_３はＣ_８〜Ｃ_１８の飽和又は不飽和アルキル基である）
を含み、
アニオン性界面活性剤が、下記式（４）で表される化合物：

（式中、Ｒ_４はＣ_６〜Ｃ_１３のアルキル基である）
、下記式（５）で表される化合物：

（式中、
Ｒ_５はＣ_８〜Ｃ_１４のアルキル基であり、
ｎは１〜１０の整数であり、
ＭはＮａ又はＮＨ（ＣＨ_２ＣＨ_２ＯＨ）_３である）
、下記式（６）で表される化合物：

（式中、Ｒ_６はＣ_１０〜Ｃ_１４のアルキル基である）
又は下記式（７）で表される化合物：

（式中、Ｒ_７はＣ_４アルキル基である）
を含み、
基材が、一価アルコール、二価アルコール、三価アルコール及びグリコールモノアルキルエーテルからなる群から選ばれる少なくとも１種のアルコール類を含み、
動粘度が、２５℃で８．５ｍｍ^２／秒以上であり、かつ１００℃で２．０ｍｍ^２／秒以下である冷却液組成物。 (1) A coolant composition containing a viscosity property improver and a substrate,
The viscosity property improver comprises at least one selected from betaine and an ionic substance and at least one anionic surfactant;
Compound in which betaine is represented by the following formula (1):

(Wherein R ₁ is a C _{8 to} C ₁₈ alkyl group)
Or a compound represented by the following formula (2):

(Wherein R ₂ is a C _{7 to} C ₁₇ alkyl group)
Including
A compound in which the ionic substance is represented by the following formula (3):

(Wherein R ₃ is a C _{8 to} C ₁₈ saturated or unsaturated alkyl group)
Including
A compound in which the anionic surfactant is represented by the following formula (4):

(Wherein R ₄ is a C ₆ -C ₁₃ alkyl group)
And a compound represented by the following formula (5):

(Where
R ₅ is a C _{8 to} C ₁₄ alkyl group,
n is an integer of 1 to 10,
M is Na or NH (CH ₂ CH ₂ OH) ₃ )
And a compound represented by the following formula (6):

(Wherein R ₆ is a C _{10 to} C ₁₄ alkyl group)
Or a compound represented by the following formula (7):

(Wherein R ₇ is a C ₄ alkyl group)
Including
The substrate 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 coolant composition according to (1), wherein the ratio of the total amount of anionic surfactant: betaine and ionic substance is 5: 5 to 1: 9.
(3) The coolant composition according to (1) or (2), wherein the viscosity characteristic improver is contained in an amount of 2.0 mmol / 100 g of composition to 10.0 mmol / 100 g of composition.
(4) The coolant composition according to any one of (1) to (3), further including a rust inhibitor.

(5) A method for operating an internal combustion engine, wherein the coolant composition according to any one of (1) to (4) is used as a coolant for the internal combustion engine.
(6) A concentrated composition for obtaining a coolant composition according to any one of (1) to (4).

  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.

  The coolant composition of the present invention contains a specific 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 viscosity property improver is an ion aggregate (ion associative agent) composed of at least one selected from betaine and an ionic substance and at least one anionic surfactant. In the present invention, betaine means a compound having a positive charge and a negative charge at positions not adjacent to each other in the same molecule. Moreover, in this invention, an ionic substance means the compound which can dissociate in water.

（式中、Ｒ_１はＣ_８〜Ｃ_１８のアルキル基である）
又は下記式（２）で表されるベタイン：

（式中、Ｒ_２はＣ_７〜Ｃ_１７のアルキル基である）
を含む。 The betaine constituting the viscosity characteristic improver of the present invention is a betaine represented by the following formula (1):

(Wherein R ₁ is a C _{8 to} C ₁₈ alkyl group)
Or betaine represented by the following formula (2):

(Wherein R ₂ is a C _{7 to} C ₁₇ alkyl group)
including.

In the above formula (1), R ₁ is a C _{8 to} C ₁₈ alkyl group, preferably a linear or branched C _{12 to} C ₁₈ alkyl group, and particularly preferably an n-dodecyl group or n. -An octadecyl group. The compound represented by Formula (1) can be used individually or in combination of 2 or more types.
Specific examples of the compound represented by the above formula (1) include amphital 20BS (manufactured by Kao Corporation) in which R ₁ is an n-dodecyl group and amphital 86B (manufactured by Kao Corporation) in which R ₁ is an n-octadecyl group. Can be mentioned.

In the above formula (2), R ₂ is a C _{7 to} C ₁₇ alkyl group, preferably a C _{9 to} C ₁₃ alkyl group, and particularly preferably an n-nonyl group. The compound represented by Formula (2) can be used individually or in combination of 2 or more types.
Specific examples of the compound represented by the above formula (2) include commercially available products such as Amphithr 20AB (manufactured by Kao Corporation) in which R ₂ is an n-nonyl group.

（式中、Ｒ_３はＣ_８〜Ｃ_１８のアルキル基である）
を含む。 The ionic substance constituting the viscosity characteristic improver is a compound represented by the following formula (3):

(Wherein R ₃ is a C _{8 to} C ₁₈ alkyl group)
including.

In the above formula (3), R ₃ is a C _{8 to} C ₁₈ saturated or unsaturated alkyl group, preferably a C _{10 to} C ₁₆ saturated or unsaturated alkyl group. The compound represented by Formula (3) can be used individually or in combination of 2 or more types.
Specific examples of the compound represented by the above formula (3) include commercially available products such as acetamine 24 (manufactured by Kao Corporation).

（式中、Ｒ_４はＣ_６〜Ｃ_１３のアルキル基である）
、下記式（５）で表される化合物：

（式中、
Ｒ_５はＣ_８〜Ｃ_１４のアルキル基であり、
ｎは１〜１０の整数であり、
ＭはＮａ又はＮＨ（ＣＨ_２ＣＨ_２ＯＨ）_３である）
、下記式（６）で表される化合物：

（式中、Ｒ_６はＣ_１０〜Ｃ_１４のアルキル基である）
又は下記式（７）で表される化合物：

（式中、Ｒ_７はＣ_４アルキル基である）
を含む。 On the other hand, the anionic surfactant constituting the viscosity characteristic improver is a compound represented by the following formula (4):

(Wherein R ₄ is a C ₆ -C ₁₃ alkyl group)
And a compound represented by the following formula (5):

(Where
R ₅ is a C _{8 to} C ₁₄ alkyl group,
n is an integer of 1 to 10,
M is Na or NH (CH ₂ CH ₂ OH) ₃ )
And a compound represented by the following formula (6):

(Wherein R ₆ is a C _{10 to} C ₁₄ alkyl group)
Or a compound represented by the following formula (7):

(Wherein R ₇ is a C ₄ alkyl group)
including.

In the above formula (4), R ₄ is a C ₆ -C ₁₃ alkyl group, preferably an n-octyl group, a branched octyl group and an n-tridecyl group, particularly preferably an n-octyl group, 2 -An ethylhexyl group and an n-tridecyl group. The compound represented by Formula (4) can be used individually or in combination of 2 or more types.

Specific examples of the compound represented by the above formula (4) include Perex OT-P (manufactured by Kao Corporation) in which R ₄ is a 2-ethylhexyl group, and Perex TR (manufactured by Kao Corporation) in which R ₄ is an n-tridecyl group. ) And the like (Kao Prototype) synthesized by changing R ₄ of Perex OT-P to an n-octyl group.

を挙げることができる。この化合物は、エマール２０Ｃ（花王社製）として市販されている。 In the above formula (5), R ₅ is a C _{8 to} C ₁₄ alkyl group, particularly preferably an n-dodecyl group.
In the above formula (5), n is an integer of 1 to 10, preferably 2 to 8, particularly preferably 3.
In the above formula (5), M is Na or NH (CH ₂ CH ₂ OH) ₃ .
As a preferable compound represented by the above formula (5), R ₅ is an n-dodecyl group,
Compound of the following formula (5-1) wherein n is 3 and M is Na:

Can be mentioned. This compound is commercially available as EMAL 20C (manufactured by Kao Corporation).

を挙げることができる。この化合物は、エマール２０Ｔ（花王社製）として市販されている。 Further, as another preferable compound represented by the above formula (5), R ₅ is an n-dodecyl group, n is 3, and M is NH (CH ₂ CH ₂ OH) _3. -2) Compound:

Can be mentioned. This compound is commercially available as EMAL 20T (manufactured by Kao Corporation).

The compound represented by Formula (5) can be used individually or in combination of 2 or more types.
In the above formula (6), R ₆ is a C _{10 to} C ₁₄ alkyl group. The compound represented by Formula (6) can be used individually or in combination of 2 or more types.

In the above formula (7), R ₇ is a C ₄ alkyl group, and examples thereof include n-butyl, sec-butyl, isobutyl and tert-butyl groups, and particularly preferred is a tert-butyl group. The compound represented by Formula (7) can be used individually or in combination of 2 or more types.

Specific examples of the compound represented by the above formula (7) include commercially available products such as Perex NB-L (manufactured by Kao Corporation) in which R ₇ is a tert-butyl group.

  The combination of betaine or cation and an anionic surfactant in the viscosity property improver of the present invention is represented by the compound represented by the formula (1), the compound represented by the formula (4), and the formula (1). And a compound represented by formula (7), a compound represented by formula (2), a compound represented by formula (4), a compound represented by formula (3) and a formula (5) A combination of compounds is preferred.

  The total ratio of the anionic surfactant: betaine and the ionic substance in the viscosity characteristic improver of the present invention is preferably 5: 5 to 1: 9. When the total ratio of the anionic surfactant: betaine and the ionic substance in the cooling liquid composition is within this range, a synergistic thickening effect can be obtained, and in particular, a sufficient thickening effect can be obtained at low temperatures. Therefore, a coolant composition having excellent warm-up properties can be obtained.

  The blending amount of the viscosity property improving agent is not particularly limited as long as the kinematic viscosity of the coolant composition at low temperature and high temperature can be within the predetermined range, but 2.0 mmol / 100 g to 10 g of the composition. It is preferably 0.0 mmol / 100 g of composition, and particularly preferably 4.0 mmol / 100 g of composition to 9.0 mmol / 100 g of composition. When the blending amount of the viscosity property improving agent is 2.0 mmol / 100 g or more of the composition, the cooling liquid composition can have a sufficient thickening effect at low temperatures, and the blending amount of the viscosity property improving agent is 10. A cooling fluid composition can have sufficient cooling performance as it is 0 mmol / 100g or less of composition. The above various viscosity characteristic improvers can also 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 includes a base having antifreezing properties. The blending amount of the base is preferably 75 to 100 parts by mass, particularly preferably 80 to 100 parts by mass with respect to 100 parts by mass of the composition (excluding the viscosity property improver).

  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 8.0 to 100 parts by mass with respect to 100 parts by mass of the composition (excluding the viscosity property improver) in consideration of antifreezing properties, and 20.0 to 100 parts by mass. Part is particularly preferred.

  The base may contain water, and the water is preferably ion-exchanged water. The blending amount of water is preferably 1.6 to 90 parts by mass, particularly preferably 8.0 to 75 parts by mass with respect to 100 parts by mass of the composition (excluding the viscosity property improver). 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. .

  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, in the coolant composition of the present invention, in order to effectively suppress corrosion of the metal used in the engine coolant path, at least one rust preventive agent is added in a range that does not affect kinematic viscosity. Can be included. 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, to the coolant composition of the present invention, for example, a pH adjuster such as sodium hydroxide or potassium hydroxide, an antifoaming agent, a colorant, a dye, or a dispersant is appropriately added within a range that does not affect kinematic viscosity. can do.

  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 (excluding the viscosity property improver).

  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 2.4 to 20.0 mmol of the above-mentioned viscosity property improving agent with respect to 100 g of the concentrated composition. It is preferable to contain 1-99.9 mass parts with respect to (except).

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to the range of an Example.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to these examples.

[Example 1-4 and Comparative Example 1-4]
Example 1
51 parts by mass of ethylene glycol and 47 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 4.4 g of stearyl betaine (manufactured by Kao Corp .: Amphitol 86B) / 100 g of the composition as a viscosity characteristic improver to the obtained mixture, the mixture was stirred and mixed uniformly. After adding sodium tert-butyl naphthalenesulfonate (product of Kao Corporation: Perex NBL) 4.4 mmol / 100 g of the composition to the obtained mixed liquid, the mixture was stirred and cooled to obtain a cooling liquid composition.

(Example 2)
Instead of stearyl betaine 4.4 mmol / 100 g of composition, stearyl betaine 6.2 mmol / 100 g of composition is used, and 4.4 mmol / sodium tert-butylnaphthalenesulfonate / sodium tert-butylnaphthalenesulfonate 2 instead of 100 g of composition A coolant composition was obtained in the same manner as in Example 1 except that .6 mmol / 100 g of the composition was used.

(Example 3)
Stearyl betaine 4.4 mmol / composition 100 g instead of stearyl betaine 1.4 mmol / composition 100 g, tert-butyl naphthalene sulfonate 4.4 mmol / composition 100 g instead of sodium tert-butyl naphthalene sulfonate 0 A coolant composition was obtained in the same manner as in Example 1 except that .6 mmol / 100 g of the composition was used.

Example 4
Stearyl betaine 4.4 mmol / 100 g composition 100 g instead of stearyl betaine 7.9 mmol / composition 100 g, sodium tert-butyl naphthalenesulfonate 4.4 mmol / 100 g composition 100 g sodium tert-butyl naphthalenesulfonate 0 A coolant composition was obtained in the same manner as in Example 1 except that .9 mmol / 100 g of the composition was used.

(Comparative Example 1)
The same as Example 1 except that stearylbetaine was not used and tert-butyl naphthalene sulfonate 8.4 mmol / composition 100 g was used instead of tert-butyl naphthalene sulfonate 4.4 mmol / composition 100 g. A coolant composition was obtained by this method.

(Comparative Example 2)
Instead of stearyl betaine 4.4 mmol / 100 g of composition, 3.5 mmol of stearyl betaine / 100 g of composition, 4.4 mmol of sodium tert-butylnaphthalenesulfonate / sodium tert-butylnaphthalenesulfonate 5 instead of 100 g of composition A coolant composition was obtained in the same manner as in Example 1, except that .3 mmol / 100 g of the composition was used.

(Comparative Example 3)
Stearyl betaine 4.4 mmol / composition 100 g instead of stearyl betaine 8.36 mmol / composition 100 g, tert-butyl naphthalene sulfonate 4.4 mmol / composition 100 g instead of tert-butyl naphthalene sulfonate 0 A coolant composition was obtained in the same manner as in Example 1 except that .44 mmol / 100 g of the composition was used.

(Comparative Example 4)
Coolant composition in the same manner as in Example 1 except that stearylbetaine 8.8 mmol / 100 g of composition is used instead of stearylbetaine 4.4 mmol / 100 g of composition, and sodium tert-butylnaphthalenesulfonate is not used. Got.

[Example 5-11 and Comparative Example 5-11]
(Example 5)
Instead of stearylbetaine, Cl ⁻ is 48000 ppm amidopropylbetaine laurate (manufactured by Kao Corporation: Amhitoal 20AB), and sodium di-2-ethylhexylsulfosuccinate (manufactured by Kao Corporation: instead of sodium tert-butylnaphthalenesulfonate) A coolant composition was obtained in the same manner as in Example 1 except that PELEX OT-P) was used.

(Example 6)
Instead of stearylbetaine 4.4 mmol / 100 g of composition, 2.2 mmol / 100 g of amide amidopropyl betaine (Kao Corporation: Amphital 20AB) with Cl ⁻ of less than 1 ppm was used, and sodium tert-butylnaphthalenesulfonate A coolant composition was obtained in the same manner as in Example 1, except that 2.2 mmol / sodium di-2-ethylhexylsulfosuccinate 2.2 mmol / 100 g of composition was used instead of 4.4 mmol / 100 g of composition.

(Example 7)
A coolant composition was obtained in the same manner as in Example 1 except that lauryl betaine was used in place of stearyl betaine and di-2-ethylhexyl sulfosuccinate sodium was used in place of sodium tert-butylnaphthalenesulfonate. .

(Example 8)
Instead of stearyl betaine 4.4 mmol / 100 g composition 100 g lauryl betaine / 100 g composition is used and 4.4 mmol sodium tert-butylnaphthalenesulfonate / 100 g composition 100 g di-n-octylsulfosuccinic acid A coolant composition was obtained in the same manner as in Example 1 except that sodium (Kao prototype) 2.2 mmol / 100 g of the composition was used.

Example 9
Instead of stearyl betaine 4.4 mmol / 100 g composition 100 g lauryl betaine / 100 g composition is used and 4.4 mmol sodium tert-butylnaphthalenesulfonate / 100 g composition 100 g sodium ditridecylsulfosuccinate (Kao) A cooling liquid composition was obtained in the same manner as in Example 1 except that 2.2 mmol / 100 g of the composition was used.

(Example 10)
Instead of stearyl betaine, coconutamine acetate (Kao Corporation: Acetamine 24) was used, and sodium tert-butylnaphthalenesulfonate instead of sodium polyoxyethylene (POE) lauryl ether sulfate (Kao Corporation: Emar 20C) A coolant composition was obtained in the same manner as in Example 1 except that was used.

(Example 11)
In place of stearyl betaine, coconut amine acetate was used, and in place of sodium tert-butylnaphthalenesulfonate, polyoxyethylene (POE) lauryl ether sulfate triethanolamine (TEA) (manufactured by Kao Corporation: Emar 20T) was used. Except for the above, a coolant composition was obtained in the same manner as in Example 1.

(Comparative Example 5)
A coolant composition was obtained in the same manner as in Example 1 except that sodium octylbenzenesulfonate (manufactured by Kao Corporation: Viscotop A) was used instead of sodium tert-butylnaphthalenesulfonate.

(Comparative Example 6)
A coolant composition was obtained in the same manner as in Example 1 except that sodium lauryl sulfate (manufactured by Kao Corporation: Emar 2F-30) was used instead of sodium tert-butylnaphthalenesulfonate.

(Comparative Example 7)
A coolant composition was obtained in the same manner as in Example 5 except that sodium octylbenzenesulfonate was used instead of sodium di-2-ethylhexylsulfosuccinate.

(Comparative Example 8)
A coolant composition was obtained in the same manner as in Example 10, except that sodium octylbenzenesulfonate was used in place of sodium polyoxyethylene (POE) lauryl ether sulfate.

(Comparative Example 9)
A coolant composition was obtained in the same manner as in Example 10 except that sodium lauryl sulfate was used instead of polyoxyethylene (POE) sodium lauryl ether sulfate.

(Comparative Example 10)
In the same manner as in Example 10, except that C _{16 to} C ₁₈ alkyltrimethylammonium chloride (Kao Co., Ltd .: Viscotop 100B) containing hexadecyltrimethylammonium chloride as a main component was used instead of coconutamine acetate. A coolant composition was obtained.

(Comparative Example 11)
A coolant composition was obtained in the same manner as in Example 10 except that cetyltrimethylammonium chloride (manufactured by Kao Corporation: Cotamine 60W) was used instead of coconut amine acetate.

  The kinematic viscosities at 25 ° C. and 100 ° C. of the coolant compositions obtained in Example 1-11 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 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 using a simple thermal property evaluation test apparatus at room temperature of 25 ° C. (see FIG. 1), and the time required for the aluminum casting to rise from 25 ° C. to 60 ° C. was measured. The result of Comparative Example 1 (240 seconds) was set to a reference value of 1.0.

<Cooling performance>
The cooling 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 temperature of 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.
Tables 1 and 2 show the measurement results of kinematic viscosity, warm-up performance, and cooling performance of the coolant compositions obtained in Example 1-11 and Comparative Example 1-11.

  From Table 1 and Table 2, the coolant composition of Example 1-11 has a higher kinematic viscosity at low temperatures, improved warm-up performance, and higher temperatures than the coolant composition of Comparative Example 1. The kinematic viscosity was sufficiently lowered, and the cooling performance was equivalent. Comparing the cooling liquid composition of Example 1-4 and the cooling liquid composition of Comparative Example 1-4 with different anionic surfactant: betaine ratios, the cooling liquid composition of Example 1-4 was at a low temperature. The kinematic viscosity was high, showed sufficient warm-up performance, and kinematic viscosity decreased sufficiently at high temperatures, and showed sufficient cooling performance. The kinematic viscosity drop is sufficient and the cooling performance is excellent, but the kinematic viscosity at low temperature is low and the warm-up performance is poor, and the cooling fluid compositions of Comparative Examples 3 and 4 are separated or non-uniform at low temperature. Precipitation was observed.

  Further, the coolant compositions of Examples 1 and 5-9 had high kinematic viscosity at low temperature and sufficient kinematic viscosity reduction at high temperature, and showed sufficient warm-up performance and cooling performance. The cooling fluid compositions of Comparative Examples 5 to 7 in which the surfactant was replaced with sodium octylbenzenesulfonate or sodium lauryl sulfate had low kinematic viscosity at low temperatures and poor warm-up performance (Comparative Examples 5 and 7). Alternatively, separation or non-uniform precipitation was observed at a low temperature (Comparative Example 6).

  In addition, the coolant compositions of Examples 10 and 11 had high kinematic viscosity at low temperatures, showed excellent warm-up performance, and had sufficient kinematic viscosity reduction at high temperatures, showing sufficient cooling performance. In the cooling liquid compositions of Comparative Examples 8 and 9 in which the anionic surfactant was replaced with sodium octylbenzenesulfonate or sodium lauryl sulfate, the kinematic viscosity at a low temperature compared with the cooling liquid compositions of Examples 10 and 11 Comparative example in which the ionic substance is replaced with hexadecyltrimethylammonium chloride or cetyltrimethylammonium chloride, which is low in temperature and inferior in warm air performance (Comparative Example 8), or is separated or non-uniformly precipitated at a low temperature (Comparative Example 9). In the cooling liquid compositions of Nos. 10 and 11, the kinematic viscosity at low temperatures is low compared to the cooling liquid composition of Example 10, the warming performance is inferior, and the cooling liquid compositions are low in temperature. Or uneven deposition was observed.

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

Claims (6)

A cooling liquid composition containing a viscosity characteristic improver and a substrate,
Viscosity characteristics modifier, and one of the betaine even without least consists of at least one anionic surfactant, betaine, compounds represented by the following formula (1):

(Wherein R ₁ is a C _{8 to} C ₁₈ alkyl group)
Or a compound represented by the following formula (2):

(Wherein R ₂ is a C _{7 to} C ₁₇ alkyl group)
Only including,
A anion surfactant is represented by the following formula (4) compound:

(Wherein R ₄ is a C ₆ -C ₁₃ alkyl group )
Or represented by the following formula (7) Compound:

(Wherein R ₇ is a C ₄ alkyl group)
Including
The substrate 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. Anionic surfactants: Betai ratio of emissions is 5: 5 to 1: 9 coolant composition of claim 1 which is. The coolant composition according to claim 1 or 2 , comprising a viscosity characteristic improver in an amount of 2.0 mmol / 100 g of composition to 10.0 mmol / 100 g of composition. The coolant composition according to claim 1, further comprising a rust inhibitor. Used coolant composition according to any one of claims 1 to 4 as a coolant for the internal combustion engine, a method of operating an internal combustion engine. Concentrate composition for obtaining the coolant composition according to any one of claims 1 to 4.

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