WO2005054397A1

WO2005054397A1 - Cooling fluid composition

Info

Publication number: WO2005054397A1
Application number: PCT/JP2003/015330
Authority: WO
Inventors: Hiroshi Egawa; Hidemi Kado
Original assignee: Shishiai-Kabushikigaisha
Priority date: 2003-12-01
Filing date: 2003-12-01
Publication date: 2005-06-16
Also published as: JPWO2005054397A1; AU2003304592A1

Abstract

A cooling fluid composition containing a glycol as a primary component, characterized in that it further comprises (a) 0.1 to 10 wt % of at least one selected from among aliphatic monobasic acids, alkylbenzoic acids and salts thereof, (b) 0.01 to 2 wt % of 2-phosphonobutane-1, 2, 4-tricarboxylic acid and (c) 0.01 to 2 wt % of at least one selected from among polymers or copolymers of unsaturated monoethylene dicarboxylic acids having four to six carbon atoms or salts thereof, polymers or copolymers of unsaturated monoethylene monocarboxylic acids having four to six carbon atoms or salts thereof and copolymers of the above unsaturated monoethylene dicarboxylic acid having four to six carbon atoms or a salt thereof and the above unsaturated monoethylene monocarboxylic acid having four to six carbon atoms or a salt thereof. The cooling fluid composition exhibits excellent capability for the prevention of corrosion of aluminum or an aluminum alloy and also allows the reduction of the phenomenon that a clearance is formed between faces in a mechanical sealing portion of a water pump of an internal combustion engine.

Description

Akira Itoda Coolant composition

TECHNICAL FIELD The present invention relates to a coolant composition mainly used for a coolant of an internal combustion engine (more particularly, relates to a coolant composition for an internal combustion engine). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling liquid composition that is effective in reducing a reduction in face opening in a mechanical seal portion.

'' Generally, the coolant composition used in the cooling system of internal combustion engines such as engines mainly contains glycols and alcohols that lower the freezing point to prevent freezing during the cold season. Metal corrosion inhibitor is added to prevent corrosion of steel. Conventionally, metals such as aluminum or aluminum alloys, iron, steel, brass, solder, and copper have been used in the cooling system of internal combustion engines. In particular, in recent years, aluminum or aluminum alloys have been diversified as cooling system components for the purpose of reducing the weight of automobile bodies. These metals corrode on contact with water or air. In order to prevent this, coolants used in the cooling system of internal combustion engines such as engines are used for phosphates, amine salts, borates, nitrates, nitrites, silicates, and organic acids. And other metal corrosion inhibitors. In particular, phosphates have been used in many coolant compositions because of their excellent corrosion protection of aluminum or aluminum alloys. However, in the case of a coolant composition containing phosphate, the hard water component in the coolant is A large amount of precipitate was formed when diluted with hard water, since a precipitate was formed by reacting with water. The formation of sediment not only deteriorated the function of the coolant to prevent corrosion, but also caused the generated sediment to accumulate in the circulation path of the cooling system and block the cooling system. On the other hand, a non-phosphorus-based coolant composition containing no phosphate has been proposed. The non-phosphorus-based cooling liquid composition contains, for example, daricols as a main component and contains p-tert-butylbenzoic acid, 2-ethylhexanoic acid, and benzoate and / or nitrate. (See Japanese Unexamined Patent Publication No. 2000-109980). Since this cooling liquid composition does not contain a phosphate, it does not form a precipitate even when diluted with hard water. However, this cooling liquid composition has a problem that the function of preventing corrosion of aluminum under running water is low, and aluminum is corroded. On the other hand, the conventional coolant composition was added with a metal corrosion inhibitor of usually about 4% in order to obtain a predetermined protective effect, and had a considerably high concentration. For this reason, under high temperature conditions, daricols, which is a main component of the coolant composition, are vaporized in the mechanical seal portion of the water pump, and the metal corrosion inhibitor in the coolant composition is partially evaporated. In this case, it was deposited as a solid and deposited. When the metal corrosion inhibitor precipitates and accumulates in this manner, the close contact state of the mechanical seal portion cannot be ensured, and the so-called “face opening” phenomenon may occur. Therefore, in order to solve such problems, the corrosion resistance and hard water stability of metals, especially aluminum and iron-based metals, have been improved, and the `` face opening '' phenomenon in mechanical seals has been reduced. Coolant compositions have been proposed by the applicant. The cooling liquid composition contains one or more alkyl benzoic acids or an alkali metal salt, an ammonium salt or an amine salt thereof, a hydrocarbon triazole, and an alkali metal nitrate, and has an aliphatic monobasic acid in the components. Does not contain (See Japanese Patent Application Laid-Open No. Hei 8-109484).

However, this coolant composition had a problem that the function of preventing corrosion of aluminum under running water was low. Disclosure of the invention

Problems to be Solved by the Invention The present invention has been made in view of the above circumstances, and has an excellent anti-corrosion property of aluminum and an aluminum alloy, and a reduction in face opening in a mechanical seal portion of a water pump. It is an object of the present invention to provide a cooling liquid composition that can perform the cooling. Means for Solving the Problems In order to solve the above problems, the present invention provides a cooling liquid composition containing a glycol as a main component, comprising: (a) 0.1 to 10% by weight of At least one selected from aliphatic monobasic acids, alkylbenzoic acids or salts thereof, and (b) 0.01 to 2% by weight of 2-phosphonobutane-11,2,4 tricarboxylic acid; c) 0.01 to 2% by weight of a polymer or copolymer of an unsaturated monoethylene dicarboxylic acid having 4 to 6 carbon atoms or a salt thereof (hereinafter referred to as monoethylene dicarboxylic acids); Polymers and copolymers of a saturated monoethylene monocarboxylic acid or a salt thereof (hereinafter, referred to as monoethylene monocarboxylic acids), or the above-mentioned unsaturated monoethylene dicarboxylic acid having 4 to 6 carbon atoms or a salt thereof and the above-mentioned 4 to 6 carbon atoms. Unsaturated monoethylenmo SUMMARY OF THE INVENTION A gist of the present invention is a coolant composition comprising at least one selected from the group consisting of copolymers of carboxylic acids and salts thereof (hereinafter, referred to as polycarboxylic acids). Dalicols, which are the main components of the coolant composition of the present invention (hereinafter simply referred to as composition), include ethylene glycol, propylene glycol, and 1,3-butylene glycol. Examples include coal, hexylene glycol, diethylene glycol, and glycerin. Among them, ethylene glycol and propylene glycol are preferable in terms of chemical stability, handling, price, and availability. Among the components (a), aliphatic monobasic acids or salts thereof include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, pendecanoic acid, dodecanoic acid Oleic acid, linoleic acid, linolenic acid, ricinoleic acid, stearic acid and their alkali metal salts, ammonium salts and the like can be mentioned as preferred examples. Examples of the alkyl benzoic acid include P-toluic acid, P-ethyl benzoic acid, p-propyl benzoic acid, p-isopropyl benzoic acid, and p-butyl benzoic acid. Salts, ammonium salts, amine salts and the like can be mentioned. Particularly preferred are alkali metal salts, and among them, sodium salts and potassium salts are most preferred.

(a) The component, alkyl benzoic acid and aliphatic monobasic acid or their salts, exhibit excellent anticorrosion performance, particularly against aluminum and iron-based metals, and prevent corrosion of metals in cooling systems, This suppresses the formation of precipitates due to the reaction between the hard water component contained in the coolant and the component contained in the coolant, and has a stabilizing effect on hard water. Alkyl benzoic acid and aliphatic monobasic acid or their salts are 0.1 to 10 weight

It is included in the range of%. If the content of alkylbenzoic acid and aliphatic monobasic acid or their salts is less than 0.1% by weight, the corrosion-inhibiting function is not sufficiently exhibited. Is not effective, and is uneconomical.

The component (b), 2-phosphonobutane-1,1,2,4 tricarboxylic acid, is a heterogeneous gold It exhibits excellent corrosion protection against intermetallic contact, especially between aluminum alloys, iron and solder and dissimilar metals, and also exhibits excellent corrosion resistance against aluminum heat transfer surface corrosion. It is. Furthermore, even in the presence of phosphoric acid, it has the function of suppressing the formation of precipitates due to the reaction between phosphate and hard water components in the solution.

2-Phosphonobtan-1,2,4 tricarboxylic acid is contained in the range of 0.01 to 2% by weight. If the content of polycarboxylic acids and the like is less than 0.01% by weight, the corrosion-preventing function is not sufficiently exhibited. This is because

Preferred examples of the monoethylene monocarboxylic acids in the polycarboxylic acids (c) as component (c) include, for example, acrylic acid, methacrylic acid, acrylic acid, vinyl acetic acid, and alkali metal salts and ammonium salts thereof. it can. Monoethylene dicarboxylic acids include, for example, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and alkali metal salts and ammonium salts thereof, and maleic acid is most preferred. It is. Preferable examples of the polymer and copolymer of monoethylene dicarboxylic acid, the polymer and copolymer of monoethylene monocarboxylic acid, and the copolymer of monoethylene dicarboxylic acid and monoethylene monocarboxylic acid include polymalein. Examples include acids, polyacrylic acid, and maleic / acrylic acid copolymer. These polycarboxylic acids and the like have a function of effectively suppressing the precipitation of the hard water component contained in the coolant and the metal corrosion inhibitor in the coexistence of a phosphate. Excellent stability at dilution. It also has the function of preventing corrosion of aluminum or aluminum alloy and the function of preventing blackening. In particular, polymaleic acid or an alkali metal salt or an ammonium salt thereof has an excellent effect of preventing blackening. The molecular weight of the polymer or copolymer in the above-mentioned polycarboxylic acids and the like is preferably 100 to 2000. If the molecular weight is less than 1000, sufficient hard water stability, corrosion prevention function and blackening prevention function will not be obtained, and if the molecular weight exceeds 2000, it will be difficult to dissolve in the composition. Become. Further, the copolymer is in a polymerization form such as random polymerization or block polymerization. Polycarboxylic acids and the like are contained in the range of 0.01 to 2% by weight. If the content of polycarbonates, etc. is less than 0.01% by weight, the functions of preventing precipitation, preventing corrosion and preventing blackening are not sufficiently exhibited, and if the content exceeds 2% by weight, It is not economical because it is not enough. The composition of the present invention comprises a metal such as aluminum, aluminum alloy, iron, steel, brass, solder, copper, etc., by coexistence of the three components (a) to (c) in the main component. It has the effect of being excellent in corrosion inhibition and hard water stability in the presence of phosphate.

In particular, the component (b) and the component (c) provide an excellent effect of preventing corrosion of aluminum and aluminum alloys at high temperatures, and have a high corrosion inhibitory property and hard water stability with a small content. Therefore, even under high temperature conditions, the precipitation and accumulation of metal corrosion inhibitor solids due to the vaporization of glycols, the main component, in the mechanical seal portion of the water pump are reduced. The occurrence of the "face opening" phenomenon is suppressed, and the sealing state of the seal portion is ensured. Further, the composition of the present invention can also contain a phosphate. By containing a phosphate, the corrosion prevention of aluminum and aluminum alloys in particular can be further improved. Examples of the phosphate include orthophosphoric acid, pyrophosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, and the like, and one or more of these can be contained. The content of the phosphate is not particularly limited, but is preferably contained in the range of 0.01 to 2.0% by weight. Further, in the case of the composition of the present invention, a form not containing molybdate may be employed. In this case, there is an advantage that the adverse effect of promoting the oxidative deterioration of glycols by molybdate can be prevented. Effects of the Invention According to the coolant composition of the present invention, the main component is selected from (a) 0.1 to 10% by weight of an aliphatic monobasic acid, an alkylbenzoic acid or a salt thereof. At least one kind; (b) 0.01 to 2% by weight of 2-phosphonobutane-1,2,4 tricarboxylic acid; and (c) 0.01 to 2% by weight of a polycarboxylic acid. The coexistence of the three components (1) and (2) has the effect of providing excellent corrosion protection for metals such as aluminum, aluminum alloys, iron, steel, brass, solder, and copper, and excellent hard water stability in the presence of phosphate. You can do it. In particular, the component (b) and the component (c) provide an excellent effect of preventing corrosion of aluminum and aluminum alloys at high temperatures, and have a high corrosion inhibitory property and hard water stability with a small content. Therefore, even under high-temperature conditions, the precipitation and accumulation of metal corrosion inhibitor solids due to the vaporization of the main component, dalicols, are reduced in the mechanical seal of the water pump. The occurrence of the "face opening" phenomenon is suppressed, and the sealing state of the seal portion is ensured. Brief Description of Drawings

Fig. 1 is a schematic diagram showing a leak test device for checking the leakage of coolant from the mechanical seal. Explanation of symbols

1: Coolant

2: chamber one

3: Mechanical seal 4: Mounting base

5: Rotary axis

6: Holding member

7: Heater

8: Pressurizing port

9: Collection tube Best mode for carrying out the invention Hereinafter, the composition of the present invention will be described in more detail.

Table 1 shows Examples 1 and 2 of the present invention and Comparative Examples 1 to 4. Example 1

Example 2 contains the components (a) to (c), and Example 2 further includes phosphoric acid in Example 1. Comparative Example 1 contains the component (a) but does not contain the components (b) and (c), Comparative Example 2 contains the components (a) and (c), and Comparative Example 3 contains the component (a). a) Component containing phosphoric acid, Comparative Example 4 contains only component (a). In Examples 1 and 2 and Comparative Examples 1 to 3, p-tert-butylbenzoic acid was contained as the component (a), and Comparative Example 4 contained toluic acid as the component (a).

table 1

8

Replacement paper (Rule 26) Next, the samples of Examples 1 and 2 and Comparative Examples 1 to 4 were subjected to a metal corrosion test to confirm the change in mass of each metal and to confirm the presence or absence of abnormalities in appearance. The results are shown in Table 2. The metal corrosion test was carried out based on the JISK2 2 3 4 metal corrosion test, and aluminum metal, iron, steel, brass, solder, and copper test pieces were used as the metals for this test. .

Table 2

From Table 2, it was confirmed that all of the samples had excellent corrosion protection against any of the metals and had little change in appearance. Next, the samples of Examples 1 and 2 and Comparative Examples 1 to 3 were subjected to a high-temperature aluminum heat transfer surface test to confirm the change in the mass of each metal and the presence or absence of abnormal appearance. The results are shown in Table 3. JISK for high temperature aluminum heat transfer surface test

The test was carried out in accordance with the rules for corrosion resistance on aluminum heat transfer surfaces in 2 324. However, the test temperature was 160 ° C and the heat-resistant glass cell was made of stainless steel.

Table 3.

9

Replacement paper (Rule 26) From Table 3, it can be seen that the samples of Example 1, Example 2, and Comparative Example 1 had a smaller amount of corrosion than Comparative Examples 2 and 3, and no abnormalities were observed in appearance. However, it was confirmed that the high-temperature aluminum heat transfer surface had excellent corrosion protection. Next, of Example 1 and Example 2, Example 2 containing phosphoric acid in addition to components (a) to (c), and (a) containing no components (b) and (c). ) A hard water stability test was performed on each sample of Comparative Example 3 containing p-tert-butylbenzoic acid and phosphoric acid as components. In the hard water stability test, each sample to be subjected to the test was prepared by dissolving 48 mg ZL of sodium sulfate, 165 mg ZL of sodium chloride, 38 mg / L of sodium hydrogen carbonate, and 275 mg / L of calcium chloride in distilled water using synthetic hard water. After dilution to 50% by weight, the diluted solution was left at 88 t for 24 hours, and the appearance of the test solution after the test was observed. The results are shown in Table 4.

Table 4

From Table 4, precipitation of the precipitate was confirmed in the sample of Comparative Example 3, but no precipitation was observed in the sample of Example 2. From this, it was confirmed that high stability against hard water can be ensured by the coexistence of the three components (a) to (c). Next, a mechanical seal single leak test was performed on Example 1 and Comparative Examples 1, 2, and 4. The test method was performed by creating a leak test device shown in Fig. 1.

In the leak test apparatus, a mechanical seal 3 is provided at the center of a chamber 2 filled with a coolant 1 obtained by diluting a coolant composition with water, and the mechanical seal 3 has a hollow mounting ^ 4. Disk-shaped holding member 6 that is connected to the rotating shaft 5 and rotates together And is held at a predetermined pressure. The mechanical seal 3 is formed of a fixed ring 3 a attached to the mounting base 4 and a rotating ring 3 b that rotates the holding member 6 integrally, and the fixed ring 3 a and the rotating ring 3 b are brought into close contact with each other. This prevents the coolant 1 from entering the mechanical seal 3. Further, a heater 7 for heating the coolant 1 to a predetermined temperature is mounted inside the chamber 1, and further, the coolant 1 is externally pressurized at a predetermined pressure on the ceiling surface of the chamber 12. Pressurizing port 8 is formed. Then, in the test, when the coolant 1 leaks from the sliding surface between the fixed ring 3a and the rotating ring 3b into the inside of the mechanical seal 3, the leaked liquid 1a flows along the outer peripheral surface of the rotating shaft 5 to the atmosphere side. Leaks into the mounting table 4 and accumulates in the collection pipe 9. Therefore, the accumulated leaked liquid 1a was quantified. Mechanical seal itself leak test, coolant 1 concentrations 5 0 v / v%, the liquid temperature 9 0 ° C, the rotation number 6 5 0 0 rpm, the external pressure 1. 0 kg / cm 2 in ² conditions 0 I went for 0 hours. Table 5 shows the results.

Table 5

From Table 5, it can be seen that Example 1 has a leakage amount of 9 m1 and Comparative Examples 1, 2 and 4 have 19 ml, 17 m1 and 3 lm1, respectively. It is judged that the leakage amount of 1 is small. From this, it is determined that the coexistence of the three components (a) to (c) in the coolant can suppress the so-called “plane opening” phenomenon.

11

Difference paper (Rule 26)

Claims

Scope of Word

1. A coolant composition containing glycols as a main component,

(a) 0.1 to 10% by weight of at least one selected from aliphatic monobasic acids, alkylbenzoic acids or salts thereof,

(b) 0.01 to 2% by weight of 2-phosphonobutane-1,2,4 tricarboxylic acid;

(c) 0.01 to 2% by weight of a polymer or copolymer of an unsaturated monoethylene dicarboxylic acid or a salt thereof having 4 to 6 carbon atoms, and an unsaturated monoethylene monocarbon having 4 to 6 carbon atoms. A polymer or copolymer of an acid or a salt thereof, or a copolymer of the unsaturated monoethylene dicarboxylic acid having 4 to 6 carbon atoms or a salt thereof and the unsaturated monoethylene monocarboxylic acid or a salt thereof having 4 to 6 carbon atoms. A coolant composition comprising: at least one selected from the group consisting of:

2. The cooling liquid composition according to claim 1, wherein the monoethylenedicarboxylic acid or a salt thereof is maleic acid or an alkali metal salt or an ammonium salt thereof.

3. The cooling liquid composition according to claim 1, further comprising a phosphate.

4. The coolant composition according to claim 1, wherein the coolant composition does not contain molybdate.

5. The coolant composition according to claim 3, wherein the composition does not contain molybdate.