JPH0532702B2 - - Google Patents

Description

[Detailed description of the invention]

This invention detects the amount of copper-based rust preventive agent in cooling water as a difference in color density and compares this with a standard color sample to determine the degree of deterioration of cooling water that can be easily measured. It's about how to do it. This invention was developed specifically to easily test the deterioration state of cooling water for internal combustion engines, and can similarly be applied to determining the degree of deterioration of various cooling fluids used for other purposes. Currently, the degree of deterioration of cooling water for internal combustion engines is determined by measuring the amount of dissolved metals and the content of rust inhibitors using analytical equipment, and the specific gravity, refractive index, etc. are also measured to control the concentration. There is. However, although the measurement of dissolved metal content and rust preventive content measurement using analytical instruments is accurate and suitable for determining the degree of deterioration of cooling water,
These methods require expensive analytical equipment and a lot of man-hours, and it is not possible to easily determine the deterioration of cooling water on site. On the other hand, when measuring specific gravity or refractive index, it is possible to measure the concentration of antifreeze used in cooling water, but it is impossible to measure the concentration of rust inhibitors used in cooling water, which are used at concentrations as low as 5%. It is. Furthermore, with these concentration measurements, it is not possible to measure the amount of rust preventive agent contained in the cooling water, and it is impossible to prevent troubles due to deterioration of the rust preventive agent. Nowadays, in response to the demands of the times for higher engine speeds, lighter vehicle bodies, and energy savings, modern automobile engines are increasingly being made of aluminum alloy, slimmer, or have a radiator mechanism with a lower capacity. Furthermore, the quality of radiator solutions for cooling automobile engines is gradually improving as various additives, including antifreeze and rust preventive agents, are used together with water. The improved quality of this radiator solution has made it extremely convenient for users in that it can withstand long-term use and eliminates the troublesome work of replacing it.However, as mentioned above, the small structure of the engine itself The radiator solution is placed in a harsh environment due to the use of aluminum alloys, aluminum alloys, or faster circulation of the radiator solution by powerful pumps due to the gradual decrease in the capacity of the radiator mechanism, which inevitably leads to a decline in the functionality of the additives. Rapid deterioration of the radiator solution is unavoidable. Therefore, when using the radiator solution continuously for a long period of time without replacing it as in the past,
This may even cause the engine itself to deteriorate and cause a serious accident. Therefore, it is desired to develop a technology that can easily determine the deterioration of radiator solution.
As mentioned above, a satisfactory determination technique has not yet been developed. The inventor of this invention discovered that the metal ion that greatly affects the functional deterioration of the radiator solution is copper ion, and that copper ions such as benzotriazole, methylbenzotriazole, mercaptozenzothiazole, They focused on the fact that a copper-based rust preventive agent is involved, and discovered that this copper-based rust preventive agent can be easily detected, and that the degree of deterioration of a radiator solution can be determined based on changes in color density, thereby completing this invention. Note that in addition to copper ions, aluminum ions, iron ions, lead ions, and zinc ions may exist in the radiator solution, but copper ions, which have the least tendency to ionize, have the strongest influence on other metals. It has been found that quantitative measurement of copper-based rust inhibitors related to copper ion generation is sufficient for determining the deterioration of radiator solutions. Hereinafter, details of the present invention will be explained with reference to drawings showing one embodiment. As shown in FIGS. 1 and 2, in the simple method for determining deterioration of internal combustion engine cooling water, etc. of the present invention, it is necessary to prepare a reagent, an extract, and a standard color sample chart. That is, the precipitation reagent 1 is placed in a bottle 2, the coloring reagent 6 is placed in a bottle 7, and the test tubes 3 and standard color sample chart 4 are stored in a case 5, for example. Extract liquid 8 is also placed in bottle 9 and prepared. Precipitation reagent 1 is a water-soluble metal salt of cupric ammonium chloride, copper sulfate, copper nitrate, cuprous chloride, or cupric chloride, and is combined with a copper-based rust inhibitor such as benzotriazole, methylbenzotriazole, or mercaptobenzothiazole. A substance that reacts to produce a colored precipitate and can be distinguished by color from precipitates such as metal hydroxides and phosphates present in degraded antifreeze is used. The coloring reagent 6 contains a substance that can react with copper ions in the cooling water to produce a coloring compound, and such substances include sodium diethyldithiocarbamate, anhydrous sodium sulfate, triethanolamine, and a compound with an average molecular weight of 4000. Certain polyethylene glycol 4000S (trade name, manufactured by Sanyo Chemical Industries, Ltd.) and ethylenediaminetetraacetate 4Na
and sodium citrate and alizarin cyanine blue. Extract liquid 8 is one that can separate and extract the coloring compound, and examples of such substances include ethyl acetate, butyl acetate, isoamyl alcohol, chloroform,
Using carbon tetrachloride, methyl ethyl ketone, and benzene. The reference color sample chart 4 is as shown in Figure 2.
This figure shows a large number of color densities that vary in stages depending on the amount of copper-based rust inhibitor. Next, in the test, the solution to be tested (radiator solution) is taken out and put into a test tube 3, and an excess of the precipitation reagent 1 is added thereto. Precipitation reagent 1 can be used as it is in powder, granule or other solid state.
Alternatively, when it is added to a test liquid in the form of an aqueous solution and reacted with a copper-based rust inhibitor, it forms a colored precipitate.
All of the copper-based rust inhibitors react with the copper ions contained in the precipitation reagent 1, leaving excess copper ions. The resulting precipitate is filtered through a filter paper, a reagent that can react with the copper ion of sodium diethyldithiocarbamate to produce a coloring compound is added to the filtered solution, and the coloring compound is extracted with an extractant such as ethyl acetate. The degree of deterioration of the test liquid is determined by comparing and contrasting it with a standard color sample chart whose color density varies depending on the concentration of copper ions. In other words, if the amounts of the test liquid and precipitation reagent 1 are fixed, the copper ions contained in the filtered liquid will have a constant value depending on the concentration of the copper-based rust preventive agent, and the copper ion concentration will change. The amount of copper-based rust preventive agent remaining can be determined by Next, three types of standard color sample charts [A], [B], and [C] are shown as examples of standard color sample charts that are prepared in advance. The reagents and samples used here are as follows. Reagent (1) Heat and dissolve 119 g of benzotriazole (BT) in ethylene glycol to make 1. Reagent (2) Heat and dissolve 133 g of methylbenzotriazole (TT) in ethylene glycol to give 1. Reagent (3) Mercaptobenzothiazole soda (MBT)
Dissolve 189g in water to make 1｜. Reagent (4) Sodium diethyldithiocarbamate 2.0g Anhydrous sodium sulfate 50.0 Triethanolamine 10.0 Polyethylene glycol 400S 37.9 and Alizarin cyanine blue 0.1 are dissolved by heating and made into particles of about 0.2 g. Reagent (5) Sodium diethyldithiocarbamate 2.0g 4Na ethylenediaminetetraacetate 2.0 Sodium citrate 2.0 Anhydrous sodium sulfate 50.0 Triethanolamine 10.0 Polyethylene glycol 4000S 33.9 and Alizarin cyanine blue 0.1 are dissolved by heating and made into particles of approximately 0.2 g. Reagent (6) Dissolve 39.2g of copper sulfate (CuSO.5HO) in water and make 1
(Cu10000ppm) Sample (7) (standard cooling water) Ethylene glycol 30.0g Water 67.0 89% phosphoric acid 0.5g Triethanolamine 1.5 and Sodium benzoate 1.0 are dissolved with stirring.

【table】

[Table] Filter and collect the filtrate using No. 4 filter paper.

【table】

[Table] Filter and collect the filtrate using No. 4 filter paper.

【table】

[Table] Filter through No. 4 filter paper and collect the filtrate. For samples (1), (2), and (3), in addition to ethylene glycol, water-soluble substances such as methyl alcohol, ethyl alcohol, and isopropyl alcohol are used. It may be dissolved in a solvent, or in water containing an alkali such as caustic soda, caustic potash, monoethanolamine, diethanolamine, triethanolamine, or the like. Samples (4) and (5) have the disadvantage that sodium diethyldithiocarbamate alone hardly clarifies the coloring state or separates the test subjects, depending on the content and concentration of the additives in the antifreeze solution. Therefore, the constituent requirements of the coloring reagent described below are essential, and their effects are as follows. Anhydrous sodium sulfate is used to facilitate separation of the test liquid and the extract, and a neutral salt such as sodium chloride can be used similarly. Triethanolamine is used to keep the test solution alkaline, and monoethanolamine, diethanolamine, sodium carbonate, etc. can be used similarly. Polyethylene glycol 4000S is used to make reagents into tablets, and it can also be made into tablets with water-soluble substances such as alginic acid, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, sodium polyacrylate, and polyethylene oxide. It can also be used as a powder without being made into tablets, or as a solution by dissolving it in water. Alizarin cyanine blue makes it easy to check the dissolution of tablets in the test solution, and is a water-soluble dye such as alizarin cyanine green, uranine conch, and erioacid red, which cannot be extracted by the extract solution. If so, you can use it as well. Ethylenediaminetetraacetate 4Na and sodium citrate are for masking iron ions, zinc ions, and lead ions, and can be used as necessary. From the above color sample standard chart, it can be seen that there is a correlation between the amount of copper-based rust inhibitor and color density. Next, we will show an example of the results when applied to the deterioration determination of radiator fluid (actual vehicle fluid) in an actual vehicle.

【table】

[Table] 10 ml of each test solution was taken into a 25 ml graduated cylinder with a stopper, 1 ml of sample (6) was added to each, shaken vigorously for 10 seconds, and filtered through No. 4 filter paper. Add 0.2g of sample (5) to each 10ml of filtrate.
The sample (5) was completely dissolved by shaking vigorously for about 5 minutes. Next, 10 ml of ethyl acetate was added to each, shaken vigorously for 10 seconds, and allowed to stand for 5 minutes. The test solution and the extract (ethyl acetate) were completely separated, with the extract forming the upper layer. Standard color sample chart [A-2], [B-2] shows the degree of coloring of this extract.
and [C-2]. As a result, the larger the amount of copper-based rust preventive agent, the less coloring, and the more the amount of copper-based rust preventive agent is increased, the less coloring occurs.
2]. As described above, this invention can detect the presence or absence of a copper-based rust preventive agent based on the shade of color of the chelate compound produced by the reaction of copper ions with a reagent. Determination of the deterioration of various types of industrial water, including water, is extremely simple and can be carried out accurately by any person without requiring any skill. In addition, the reagent is easy to handle as it can be freely handled in a solution state or solidified into tablets. This is effective for determining deterioration due to Furthermore, reagents, chemicals, instruments, etc. can be integrated into a single case along with instructions for commercialization, making it easy to determine deterioration at each site by quantifying copper-based rust preventives in internal engine coolant and other industrial water. It has the effect that can be implemented. As is clear from the above description, according to the present invention, by detecting the amount of copper-based rust preventive agent in the coolant as a difference in color shading and comparing this with a reference color sample chart, it is possible to easily improve the internal combustion engine. The degree of deterioration of the cooling water can be determined.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a reagent, and FIG. 2 is an explanatory diagram showing a standard color sample chart. 1... Reagent for precipitation, 2... Reagent bottle for precipitation, 3...
...Test tube, 4...Standard color sample chart, 5...Case, 6...Coloring reagent, 7...Coloring reagent bottle,
8...extract liquid, 9...extract liquid bottle.

Claims (1)

[Claims] 1. A standard color sample chart showing a number of color changes that vary stepwise depending on the concentration of the copper-based rust preventive agent, and a water-insoluble color chart that contains copper ions and reacts with the copper-based rust preventive agent in the test solution. A precipitation reagent comprising at least one of copper sulfate, cupric ammonium chloride, copper nitrate, cuprous chloride, and cupric chloride, which generates a salt, and copper ions in the test solution. A coloring agent composed of sodium diethyldithiocarbamate, anhydrous sodium sulfate, triethanolamine, polyethylene glycol with an average molecular weight of 4000, ethylenediaminetetraacetate 4Na, sodium citrate, and alizarin cyanine blue, which contain substances that react to produce coloring compounds. reagents for
and ethyl acetate, butyl acetate, isoamyl alcohol, chloroform, carbon tetrachloride, which can separate and extract the produced coloring compound from the test solution,
An extract consisting of at least one of methyl ethyl ketone and benzene is prepared, and the precipitation reagent is added to the test solution of cooling water to react with the copper-based rust inhibitor in the test solution. Excess copper ions are reacted with the reagent, and the amount of the copper-based rust inhibitor is measured by comparing and contrasting the color density with the presence of the extract solution, and measuring the amount of the copper-based rust inhibitor. A simple method for determining the deterioration of cooling water for an internal combustion engine, the method comprising determining the degree of deterioration of the cooling water.