A groove edge inhibitor for aluminum alloy cutting fluid after deterioration and its preparation method and application

Abstract

The present application relates to the technical fields of cutting fluid inhibitor, and discloses a tank edge inhibitor for aluminum alloy cutting fluid after deterioration and a preparation method and application thereof, wherein the tank edge inhibitor comprises special amine and bactericide, and the bactericide is composed of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.The present application can effectively solve the problem of biological stability in the use process of aluminum alloy cutting fluid under the condition of ensuring no corrosion of aluminum alloy through the composite application of special amine, methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cutting fluid inhibitors, and particularly relates to a tank edge inhibitor for aluminum alloy cutting fluid after degradation as well as a preparation method and application thereof. BACKGROUND

[0002] In the cutting process of aluminum alloy, the selection of cutting fluid has a direct impact on the quality of the workpiece and the processing efficiency. At present, the commonly used aluminum alloy cutting fluid mainly includes emulsified type and semi-synthetic type. Among them, the emulsified cutting fluid inhibits the corrosion of aluminum alloy through high oil content. The oil film with high oil content covers the surface of the aluminum alloy, effectively isolates water and oxygen, and reduces the occurrence of corrosion. The oil film can also prevent the corrosive components in the cutting fluid from directly contacting the surface of the aluminum alloy. However, the emulsified cutting fluid with high oil content is prone to bacterial growth, causing the cutting fluid to emit odor. This is because the oil provides a rich source of nutrients for bacteria, promoting the reproduction of bacteria. The semi-synthetic cutting fluid usually adopts the following methods to inhibit corrosion in aluminum alloy processing: 1. Reducing the pH value of the cutting fluid to reduce the corrosion of aluminum alloy, but low pH value may also lead to bacterial growth, thereby affecting the stability and service life of the cutting fluid. 2. Using phosphate ester corrosion inhibitors to form a protective film on the surface of aluminum alloy to prevent aluminum alloy corrosion, however, although the phosphate ester corrosion inhibitor is effective, its decomposition products may become a source of nutrients for bacteria, promoting bacterial growth and causing the cutting fluid to emit odor.

[0003] When the on-site aluminum alloy processing cutting fluid appears bacterial growth and odor, the traditional method is to add formaldehyde releasing type bactericides such as MBM, BK, etc. However, although these bactericides containing organic bases such as monoethanolamine can effectively kill bacteria, they can also cause corrosion of aluminum alloy. While adding isothiazolinone bactericides can effectively kill bacteria, but cannot effectively increase the pH value of the on-line liquid, leading to rapid pH decrease, and thus cannot inhibit bacterial growth for a long time.

[0004] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0005] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a tank edge inhibitor for aluminum alloy cutting fluid after degradation as well as a preparation method and application thereof, aiming to solve the problem that the existing bactericides cannot complete long-acting sterilization and odor removal without corroding aluminum alloy when the existing on-site aluminum alloy processing cutting fluid appears bacterial growth and odor.

[0006] The technical scheme of the present application is as follows:

[0007] A tank edge inhibitor for aluminum alloy cutting fluid after degradation, wherein the tank edge inhibitor comprises a special amine and a bactericide, and the bactericide is composed of methyl isothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

[0008] The tank edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the specific amine is one or more of monoisopropanolamine, N-methyl diethanolamine, 2-amino-2-methyl-1-propanol and diglycolamine.

[0009] The tank edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the specific amine is 2-amino-2-methyl-1-propanol.

[0010] The tank edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the mass ratio of the specific amine to the bactericide in the tank edge inhibitor is (1-3) : 1, and the mass ratio of the methylisothiazolinone to the 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione in the bactericide is 1:1.

[0011] A preparation method of the tank edge inhibitor for aluminum alloy cutting fluid after deterioration according to the present application, wherein the method comprises the steps of:

[0012] Measuring the specific amine and the bactericide according to the proportion;

[0013] Adding the measured specific amine and bactericide into a reaction kettle, and starting the heating and stirring device to stir them uniformly to obtain a mixed solution;

[0014] Filtering the mixed solution, sterilizing it, and finally filling it to obtain the tank edge inhibitor.

[0015] The application of the tank edge inhibitor for aluminum alloy cutting fluid after deterioration according to the present application, wherein the tank edge inhibitor is directly added into a liquid tank of on-site aluminum alloy cutting fluid deterioration and corruption liquid.

[0016] The application of the tank edge inhibitor, wherein the addition amount of the tank edge inhibitor is 0.3-1.2% during use.

[0017] The application of the tank edge inhibitor, wherein the addition amount of the tank edge inhibitor is 1.2% during use.

[0018] The application of the tank edge inhibitor, wherein the addition amount of the tank edge inhibitor is 0.9% during use.

[0019] The application of the tank edge inhibitor, wherein the addition amount of the tank edge inhibitor is 0.6% during use.

[0020] Beneficial effects: The present application provides a tank edge inhibitor for aluminum alloy cutting fluid after degradation, which significantly improves the biological stability and pH buffering capacity of aluminum alloy cutting fluid during use through the synergistic effect of special amine and high-efficiency bactericide at low pH. This compounding strategy not only effectively inhibits the growth of bacteria and mold, reduces the corruption and deterioration of cutting fluid, but also enhances the stability of cutting fluid by maintaining a suitable pH value, thereby prolonging its service life. The addition of special amine not only improves the antibacterial performance of cutting fluid, but also reduces the environmental impact due to its mild properties, in line with the principles of green chemistry. In addition, the preparation method of the inhibitor of the present application is simple and easy to operate, and the prepared inhibitor is easy to add to existing cutting fluid systems, facilitating maintenance and management. The present application not only improves the cutting efficiency and processing quality, but also reduces the use cost, and at the same time improves the working environment, providing an efficient, stable and environmentally friendly solution for aluminum alloy processing. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 For the bacterial content test results of the bacteria test piece before and after adding the inhibitor in Comparative Example 1 and Examples 1-9 (from left to right, Comparative Example 1 and Examples 1-9, respectively).

[0022] Figure 2 For the aluminum corrosion semi-immersion test results of different inhibitors in Examples 1-9 (from left to right, Examples 1-9, respectively).

[0023] Figure 3 For the aluminum corrosion semi-immersion test results of different inhibitors in Examples 10-13 (from left to right, Examples 10-13, respectively). DETAILED DESCRIPTION

[0024] The present application provides a tank edge inhibitor for aluminum alloy cutting fluid after degradation, and its preparation method and application. In order to make the purpose, technical scheme and effect of the present application more clear and explicit, the present application will be further described in detail below. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application.

[0025] The terms "first", "second", "third", "fourth" and the like in the description and in the claims of the present application, and above-described drawings, if any, are used to distinguish between similar objects and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the use of the terms so-termed, where appropriate, can be interchanged with each other to the extent that the embodiments described herein can be carried out in other sequences than those illustrated or described herein. Furthermore, the terms "comprise" or "have" and any variations thereof are intended to cover non-exclusive inclusions, for example, processes, methods, systems, products, or apparatuses comprising a list of steps or units are not necessarily limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products, or apparatuses.

[0026] In the process of cutting aluminum alloy, the selection of cutting fluid has a direct impact on the quality of the workpiece and the processing efficiency. However, the existing cutting fluid (including emulsified type and semi-synthetic type) is prone to degradation after long-term use, mainly in the following aspects: bacteria breeding, causing the cutting fluid to smell. The pH value of the cutting fluid decreases, affecting the stability and service life of the cutting fluid. The commonly used antibacterial additives (such as triazine and morpholine bactericides) are alkaline, and can effectively kill bacteria only under the condition that the pH is higher than 9.0. The solvent containing organic alkali may also cause corrosion of aluminum alloy, affecting the processing quality. The isothiazolinone bactericide is relatively mild, which can kill bacteria and reduce the corrosion of aluminum alloy, but it cannot effectively improve the pH value of the online liquid, and thus cannot inhibit the breeding of bacteria for a long time.

[0027] Based on this, the present application provides a tank edge inhibitor for aluminum alloy cutting fluid after degradation, wherein the tank edge inhibitor comprises a special amine and a bactericide, and the bactericide is composed of methyl isothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

[0028] Specifically, the special amine is a class of organic compounds, which is usually connected to three different groups (such as alkyl, aryl or other substituents) by a carbon atom connected to a nitrogen atom. As an organic base, the special amine has high pH buffering capacity, which can improve the pH value of the cutting fluid, delay the decrease of the pH value, and enhance the stability of the cutting fluid. In addition, the special amine also has antibacterial properties, which can effectively inhibit the growth of bacteria in the cutting fluid and prevent the cutting fluid from smelling. The special amine is relatively mild and will not cause serious pollution to the environment, which meets the principle of green chemistry.

[0029] The application can effectively solve the problem of biological stability of aluminum alloy cutting fluid in use process under the condition of ensuring no corrosion of aluminum alloy by the complex application of triamine, methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione. In the application, triamine is introduced as a pH regulator to increase the base reserve of the cutting fluid and moderately increase the pH value; methylisothiazolinone is a broad-spectrum and efficient non-oxidizing bactericide which can maintain high bactericidal capacity under the condition of low pH of the deteriorated aluminum alloy cutting fluid and ensure the biological stability of the cutting fluid without affecting the corrosion of aluminum; 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione is a formaldehyde-releasing bactericide with higher formaldehyde content than traditional MBM and has more persistent antibacterial effect; further, the 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione is dissolved in water and does not contain ethanolamine and other organic bases which can cause corrosion of aluminum. The complex application of the three can not only enhance the broad-spectrum of the inhibitor and significantly improve the inhibition capacity to microorganisms, but also improve the stability and service life of the aluminum alloy cutting fluid online liquid.

[0030] That is to say, when the aluminum alloy is cut by using the deteriorated aluminum alloy cutting fluid, the tank edge inhibitor provided by the application is added to the tank edge to achieve the effect of not affecting the corrosion of aluminum, ensuring the sterility and no odor of the cutting fluid online liquid, and reducing the pH slowly.

[0031] In some embodiments, the triamine is one or more of monoisopropanolamine (MIPA), N-methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP95) and diglycolamine (DGA), but is not limited thereto. As preferred, the triamine is 2-amino-2-methyl-1-propanol. The 2-amino-2-methyl-1-propanol not only has excellent pH value adjusting capacity, but also has antimicrobial properties, and the 2-amino-2-methyl-1-propanol is not easy to volatilize and performs better in aluminum gas phase corrosion.

[0032] In some embodiments, the mass ratio of triamine to bactericide in the tank edge inhibitor is (1-3):1, and the mass ratio of methylisothiazolinone to 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione in the bactericide is 1:1. It is found by experiments that when the tank edge inhibitor is compounded within the range defined in the embodiments, it not only has better inhibition capacity to microorganisms, but also can improve the stability and service life of the aluminum alloy cutting fluid online liquid.

[0033] In some embodiments, the application further provides a preparation method of the tank edge inhibitor for aluminum alloy cutting fluid after deterioration, which comprises the following steps: weighing the terpene and bactericide according to the proportion; adding the weighed terpene and bactericide into a reaction kettle, and starting the heating and stirring device to stir them uniformly to obtain a mixed solution; filtering and sterilizing the mixed solution, and finally performing tanking to obtain the tank edge inhibitor.

[0034] The preparation method of the tank edge inhibitor provided by the application is simple, easy to operate, and the prepared inhibitor is easy to add to the existing cutting fluid system, which is convenient for maintenance and management.

[0035] In some embodiments, the application further provides an application of the tank edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the tank edge inhibitor is directly added into a tank of the on-site aluminum alloy cutting fluid after deterioration, and the addition amount of the tank edge inhibitor is 0.3-1.2% during use. As an example, when the addition amount of the tank edge inhibitor is 1.2%, 0.9% or 0.6%, the tank edge inhibitor not only has better bactericidal ability, but also can improve the stability and service life of the on-site aluminum alloy cutting fluid.

[0036] The application will be further explained and described below through specific examples:

[0037] In order to verify the influence of different bactericides on the bactericidal effect of the on-site aluminum alloy cutting fluid after deterioration, different bactericides are tested as shown in Table 1:

[0038] Table 1: Single and compound bactericides

[0039]

[0040] The bactericides in the above comparative examples and examples are added into the aluminum alloy cutting fluid after deterioration (pH 7.26) according to 1%, and the bacterial content before adding the inhibitor and after adding different inhibitors is tested by using a bacterium test piece, and the test results are as follows: Figure 1As shown in the figure, it can be seen that among the single-agent fungicides, methylisothiazolinone (MIT) has the most obvious antibacterial effect, followed by phenylisothiazolinone (BIT), pyridine, ethylene glycol dihydroxymethyl ether and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione (DT); while commonly used alkaline fungicides such as morpholine and s-triazine have poor antibacterial effects in low-pH corrupt fluid environments. This may be because their fungicidal activity is significantly reduced in acidic environments, resulting in an inability to effectively eliminate bacteria in low-pH aluminum alloy cutting fluid corrupt fluids. This patent carefully selected two fungicides with the best performance in aluminum corrosion performance - methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, and compounded them to form Example 9. Methylisothiazolinone can quickly inhibit the growth of microorganisms with its rapid bactericidal properties, while 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, as a fungicide that slowly releases formaldehyde, can provide a long-lasting antibacterial effect. This combination of rapid onset and long-lasting protection not only enhances the broad spectrum of the inhibitor, enabling it to act on a wider range of microbial groups, but also prolongs the overall bactericidal effect and significantly improves the ability to inhibit microorganisms. At the same time, the synergistic effect of this combination reduces the risk of microorganisms developing resistance to fungicides, thereby extending the shelf life of the product. In addition, the compound solution exhibits higher stability under different environmental conditions, which helps to extend its storage and service life. Comprehensive Figure 1 According to the test data, Example 9 has the most significant antibacterial effect, which confirms the effectiveness of the compound solution and achieves a bactericidal effect that exceeds that of a single component while ensuring that the aluminum alloy is not corroded.

[0041] Furthermore, a 7050 aluminum sheet was polished with 180-mesh and 240-mesh sandpaper, and then half-immersed in the inhibitor of Examples 1-9. After immersion for 3 hours, the sheet was taken out and photographed to observe the corrosion of the gas phase and liquid phase of the 7050 aluminum sheet. The test results are as follows: Figure 2 shown. Figure 2 The test results show that the combination of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione has a worse corrosion resistance to aluminum than the single agents of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, but exhibits milder aluminum corrosion than other examples.

[0042] In order to verify the effect of the groove edge inhibitor after degradation of the aluminum alloy cutting fluid of this patent on the improvement of the online liquid pH of the cutting fluid, the present invention tested different special amines and MIT / DT (1:1) compounds as shown in Table 2, and obtained the following inhibitor formulas.

[0043] Table 2 Different special amines and MIT / DT compounding table

[0044]

[0045] The inhibitors of Comparative Example 2 and Examples 10-13 in Table 2 were added to an aluminum alloy cutting fluid deterioration liquid taken from the field at 0.1%, and the pH values before and after adding the inhibitors were tested with a pH meter, and the test results are shown in Table 3.

[0046] Table 3 pH value test results of different examples

[0047]

[0048]

[0049] As can be seen from the data in Table 3, the pH value of the aluminum alloy cutting fluid deterioration liquid can be improved to some extent after adding the inhibitors.

[0050] A 7050 aluminum sheet was polished with 180-mesh and 240-mesh sandpaper, respectively, and then half-soaked in the inhibitors of Examples 10-13 above, and after soaking for 3 h, the 7050 aluminum sheet was taken out and photographed to observe the gas phase and liquid phase corrosion of the 7050 aluminum sheet, and the test results are shown in Figure 3 .

[0051] In combination with Table 3 and Figure 3 It can be found from the results that the inhibitor using AMP95 special amine combined with bactericide in Example 13 has a significant effect on the improvement of pH value, and performs best in aluminum gas phase corrosion. Compared with other examples, the use of AMP95 special amine can not only enhance the pH of the cutting fluid, increase the alkaline reserve and improve the biological stability, but also effectively improve the pH value without causing corrosion to aluminum.

[0052] In order to verify the influence of the compounding ratio and the addition amount of the tank-side inhibitor on the improvement of the pH value of the cutting fluid deterioration liquid and the bactericidal effect, different compounding ratios of special amines and bactericides were used in this example, and different addition amounts (0.3%, 0.6%, 0.9%, 1.2%) of the tank-side inhibitor were adopted, and the inhibitor formulations and addition ratios shown in Table 4 were obtained; at the same time, the pH value of the deterioration liquid with the added inhibitor was tested, and the results are shown in Table 5. In this example, the deterioration liquid is an emulsified cutting fluid deterioration liquid, which includes, by weight: base oil 70-80 parts, emulsified rust inhibitor 5-7 parts, phosphate ester 0.5-1 part, lubricant 4-6 parts, bactericide 1-2 parts, organic base 1-2 parts, inorganic base 0.5-1 part, emulsifier 5-7 parts, and defoamer 0.1 part.

[0053] Table 4 Corrosion liquid and tank-side inhibitor ratio table

[0054]

[0055]

[0056]

[0057] Table 5 pH value test of different examples

[0058]

[0059]

[0060] As can be seen from the data in Table 5, the addition of 0.3-1.2% of the tank edge inhibitor to the aluminum alloy cutting fluid deterioration and corruption liquid can improve the pH value of the cutting fluid to a certain extent, and under the condition of the same amount of tank edge inhibitor, when the mass ratio of special amine and bactericide in the tank edge inhibitor is (1-3): 1, the pH value is improved more obviously. As can be seen from Table 5, in Example 31, when the tank edge inhibitor is added to the aluminum alloy cutting fluid deterioration and corruption liquid at a proportion of 1.2%, and the mass ratio of special amine and bactericide in the tank edge inhibitor is 3:1, the pH value can be effectively improved to 8.47, reaching the ideal aluminum alloy cutting fluid processing pH range.

[0061] In the present application, special amine AMP95 as an effective pH regulator can increase the alkaline reserve of the cutting fluid, thereby improving the pH value to a certain extent and enhancing the stability of the cutting fluid; at the same time, the addition of bactericide effectively controls the growth of microorganisms in the corruption liquid, preventing further corruption and odor problems. This synergistic effect not only improves the biological stability of the cutting fluid, but also prolongs its service life.

[0062] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. Use of a slot edge suppressor, characterized in that, The groove edge inhibitor is directly added into the tank of the deteriorated and corrupted liquid of the aluminum alloy cutting fluid on site, and the groove edge inhibitor is composed of a special amine and a bactericide, the bactericide is composed of a methyl isothiazolinone and a 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, the special amine is 2-amino-2-methyl-1-propanol, the mass ratio of the special amine to the bactericide is (1-3):1, and the mass ratio of the methyl isothiazolinone to the 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione in the bactericide is 1:

1.

2. The use of a slot edge suppressor according to claim 1, characterised in that, In use, the adding amount of the groove edge inhibitor is 0.3-1.2%.

3. The use of the groove edge inhibitor according to claim 1, characterized in that: In use, the adding amount of the groove edge inhibitor is 1.2%.

4. The use of a slot edge suppressor according to claim 1, wherein, In use, the adding amount of the groove edge inhibitor is 0.9%.

5. The use of a slot edge suppressor according to claim 1, wherein, In use, the adding amount of the groove edge inhibitor is 0.6%.

6. The use of a slot edge suppressor according to claim 1, wherein, The preparation method of the groove edge inhibitor comprises the following steps: The special amine and the bactericide are weighed according to the proportion; The weighed special amine and bactericide are added into a reaction kettle, and a heating and stirring device is started to uniformly stir the special amine and bactericide, so that a mixed liquid is obtained; The mixed liquid is filtered, sterilized, and finally canned to prepare the groove edge inhibitor.

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