Groove edge inhibitor used after degradation of aluminum alloy cutting fluid as well as preparation method and application of groove edge inhibitor

Abstract

The invention relates to the technical field of cutting fluid inhibitors, and discloses a groove edge inhibitor used after aluminum alloy cutting fluid degradation and a preparation method and application thereof.The groove edge inhibitor comprises special amine and a bactericide, and the bactericide is composed of methylisothiazolinone and 1, 3-bis (hydroxymethyl)-5, 5-dimethylimidazolidine-2, 4-diketone. According to the aluminum alloy cutting fluid disclosed by the invention, through compound application of the special amine, the methylisothiazolinone and the 1, 3-bis (hydroxymethyl)-5, 5-dimethylimidazolidine-2, 4-diketone, the problem of biological stability in the use process of the aluminum alloy cutting fluid can be effectively solved under the condition of ensuring that an aluminum alloy is not corroded.

Description

Technical Field

[0001] The invention belongs to the technical field of cutting fluid inhibitors, and in particular relates to a groove edge inhibitor used for deteriorated aluminum alloy cutting fluid, and a preparation method and application thereof. Background Art

[0002] In the cutting process of aluminum alloy, the choice of cutting fluid has a direct impact on the quality and processing efficiency of the workpiece. At present, the commonly used aluminum alloy cutting fluids mainly include emulsified and semi-synthetic types. Among them, emulsified cutting fluids inhibit the corrosion of aluminum alloys through high oil content. The oil film with high oil content covers the surface of aluminum alloy, effectively isolating water and oxygen and reducing the occurrence of corrosion. The oil film can also prevent the corrosive components in the cutting fluid from directly contacting the surface of aluminum alloy. However, emulsified cutting fluids with high oil content are prone to breed bacteria, causing the cutting fluid to stink. This is because grease provides a rich source of nutrition for bacteria and promotes bacterial reproduction. Semi-synthetic cutting fluids usually take the following methods to inhibit corrosion in aluminum alloy processing: 1. Reduce the corrosion of aluminum alloy by lowering the pH value of the cutting fluid, but low pH value may also cause bacterial growth, thereby affecting the stability and service life of the cutting fluid. 2. Use phosphate corrosion inhibitors to form a protective film on the surface of aluminum alloys to prevent aluminum alloy corrosion. However, although phosphate corrosion inhibitors are effective, their decomposition products may become a nutrient source for bacteria, promote bacterial growth, and cause the cutting fluid to stink.

[0003] When there is bacterial growth and odor in the aluminum alloy cutting fluid on site, the traditional method is to add formaldehyde-releasing fungicides such as MBM and BK. However, these fungicides containing organic bases such as monoethanolamine can effectively kill bacteria, but they can also cause aluminum alloy corrosion. Although adding fungicides such as isothiazolinone can effectively kill bacteria, it cannot effectively increase the pH value of the online fluid, causing the pH to drop too quickly, and thus failing to inhibit bacterial growth for a long time.

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

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a groove edge inhibitor for aluminum alloy cutting fluid after deterioration, and its preparation method and application, aiming to solve the problem that when bacteria grow and stink in the existing on-site aluminum alloy processing cutting fluid, the existing bactericides cannot achieve long-term sterilization and deodorization without corroding the aluminum alloy.

[0006] The technical solution of the present invention is as follows:

[0007] A groove edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the groove edge inhibitor comprises a special amine and a bactericide, and the bactericide consists of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

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

[0009] The groove edge inhibitor used for aluminum alloy cutting fluid after degradation, wherein the special amine is 2-amino-2-methyl-1-propanol.

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

[0011] A method for preparing a groove edge inhibitor for aluminum alloy cutting fluid after degradation according to the present invention, comprising the steps of:

[0012] Weigh the tert-amine and fungicide according to the ratio;

[0013] Add the weighed special amine and fungicide into the reactor, start the heating and stirring device, stir them evenly to obtain a mixed solution;

[0014] The mixed solution is filtered and then sterilized, and finally canned to obtain the tank edge inhibitor.

[0015] An application of the groove edge inhibitor for deteriorated aluminum alloy cutting fluid as described in the present invention, wherein the groove edge inhibitor is directly added into a liquid tank of deteriorated and corrupted aluminum alloy cutting fluid on site.

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

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

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

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

[0020] Beneficial effects: The present invention provides a groove edge inhibitor for aluminum alloy cutting fluid after deterioration. The groove edge inhibitor significantly improves the biological stability and pH buffering capacity of the aluminum alloy cutting fluid during use through the synergistic effect of special amines and high-efficiency bactericides at low pH; this compounding strategy not only effectively inhibits the growth of bacteria and molds, reduces the corruption and deterioration of the cutting fluid, but also enhances the stability of the cutting fluid by maintaining a suitable pH value, thereby extending its service life; the addition of special amines not only improves the antibacterial properties of the cutting fluid, but also reduces the impact on the environment due to its mild characteristics, which complies with the principles of green chemistry. In addition, the inhibitor preparation method of the present invention is simple and easy to operate, and the prepared inhibitor is easy to add to the existing cutting fluid system, which is convenient for maintenance and management. The present invention not only improves the cutting efficiency and processing quality, but also reduces the cost of use, while improving the working environment, providing an efficient, stable and environmentally friendly solution for aluminum alloy processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The graph is a graph showing the test results of the bacterial content before and after adding different inhibitors using a bacterial test piece in Comparative Example 1 and Examples 1-9 (from left to right are Comparative Example 1 and Examples 1-9, respectively).

[0022] Figure 2 Graph showing the results of aluminum corrosion semi-immersion tests with different inhibitors in Examples 1-9 (from left to right are Examples 1-9 respectively).

[0023] Figure 3 Graph showing the results of aluminum corrosion semi-immersion tests with different inhibitors in Examples 10-13 (from left to right are Examples 10-13 respectively). DETAILED DESCRIPTION

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

[0025] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" or "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] In the aluminum alloy cutting process, the choice of cutting fluid has a direct impact on the quality of the workpiece and the processing efficiency. However, the existing cutting fluids (including emulsified and semi-synthetic types) are prone to deterioration after long-term use, which is mainly manifested in the following aspects: bacterial growth, causing the cutting fluid to stink. The pH value of the cutting fluid is reduced, affecting the stability and service life of the cutting fluid. Commonly used antibacterial additives (such as triazine and morpholine fungicides) are alkaline and can only effectively kill bacteria when the pH is higher than 9.0. The organic base solvents they contain may also cause aluminum alloy corrosion and affect the processing quality. Isothiazolinone fungicides are relatively mild, which can both kill bacteria and reduce corrosion to aluminum alloys, but they cannot effectively increase the pH value of the online fluid, and thus cannot inhibit bacterial growth for a long time.

[0027] Based on this, the present invention provides a groove edge inhibitor for aluminum alloy cutting fluid after deterioration, wherein the groove edge inhibitor includes special amine and a bactericide, and the bactericide is composed of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

[0028] Specifically, amines are a class of organic compounds, usually composed of a carbon atom connected to three nitrogen atoms of different groups (such as alkyl, aryl or other substituents). As an organic base, amines have a high pH buffering capacity, which can increase the pH value of the cutting fluid, delay the decline of the pH value, and enhance the stability of the cutting fluid; in addition, amines also have antibacterial properties, which can effectively inhibit the proliferation of bacteria in the cutting fluid and prevent the cutting fluid from stinking; amines are relatively mild and will not cause serious pollution to the environment, which is in line with the principles of green chemistry.

[0029] The present invention can effectively solve the problem of biological stability during the use of aluminum alloy cutting fluid by composite application of special amine, methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, while ensuring that the aluminum alloy is corrosion-free. In the present invention, by introducing special amine as a pH regulator, the alkali reserve of the cutting fluid is increased and the pH value is moderately increased; methylisothiazolinone is a broad-spectrum, efficient non-oxidizing bactericide, which can maintain efficient bactericidal ability under the condition of low pH of aluminum alloy cutting fluid degradation fluid, and ensure the biological stability of the cutting fluid without affecting aluminum corrosion; 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione is a formaldehyde-releasing bactericide, the formaldehyde content is higher than that of traditional MBM, and has a more lasting antibacterial effect; further, the 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione is made of water as a solvent, and does not contain organic bases such as ethanolamine that can corrode aluminum. The present invention uses these three in combination, which not only enhances the broad spectrum of the inhibitor and significantly improves the ability to inhibit microorganisms, but also improves the stability and service life of the aluminum alloy cutting fluid online fluid.

[0030] That is to say, when using degraded aluminum alloy cutting fluid to cut aluminum alloy, by adding the groove edge inhibitor provided by the present invention to the groove edge, it is possible to achieve the effect of not affecting aluminum corrosion, ensuring that the cutting fluid online is sterile, does not stink, and the pH value decreases more slowly.

[0031] In some embodiments, the special amine 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. Preferably, the special amine is 2-amino-2-methyl-1-propanol. The 2-amino-2-methyl-1-propanol not only has excellent pH adjustment ability, but also has antimicrobial properties, and the 2-amino-2-methyl-1-propanol is not easy to volatilize and performs better in aluminum vapor corrosion.

[0032] In some embodiments, the mass ratio of the special amine to the bactericide in the groove 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 through experiments that when the groove edge inhibitor is compounded within the range defined in this embodiment, it not only has a better inhibitory ability against microorganisms, but also can improve the stability and service life of the aluminum alloy cutting fluid online fluid.

[0033] In some embodiments, a method for preparing a groove edge inhibitor for deteriorated aluminum alloy cutting fluid is also provided, which includes the steps of: weighing special amine and bactericide according to a ratio; adding the weighed special amine and bactericide into a reactor, and starting a heating and stirring device to stir them evenly to obtain a mixed liquid; filtering the mixed liquid and then sterilizing it, and finally canning it to obtain the groove edge inhibitor.

[0034] The method for preparing the groove edge inhibitor provided by the invention is simple and easy to operate, and the prepared inhibitor is easy to add into the existing cutting fluid system, which is convenient for maintenance and management.

[0035] In some embodiments, a groove edge inhibitor for aluminum alloy cutting fluid after deterioration is also provided, wherein the groove edge inhibitor is directly added to the liquid tank of the aluminum alloy cutting fluid deterioration and corruption liquid on site, and during use, the addition amount of the groove edge inhibitor is 0.3-1.2%. As an example, when the addition amount of the groove edge inhibitor is 1.2%, 0.9%, and 0.6%, it not only has better sterilization ability, but also can improve the stability and service life of the aluminum alloy cutting fluid online liquid.

[0036] The present invention will be further explained below by means of specific embodiments:

[0037] In order to verify the influence of different bactericides on the sterilization effect of the online fluid of aluminum alloy deterioration cutting fluid, different bactericides were tested as single agents and compound agents as shown in Table 1:

[0038] Table 1 Single agent and compound fungicide

[0039]

[0040] The bactericides in the comparative examples and embodiments were added to the corrupted aluminum alloy cutting fluid (pH 7.26) collected from the site at 1%, and the bacterial content before and after adding different inhibitors was tested using a bacterial test sheet. The test results are as follows: Figure 1As shown in the figure, it can be seen that among the single bactericides, 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 bactericides such as morpholine and triazine have poor antibacterial effects in low pH corrupt fluid environments, which may be because their bactericidal activity is significantly reduced in acidic environments, resulting in the inability to effectively eliminate bacteria in low pH aluminum alloy cutting fluid corrupt fluids. This patent carefully selected two bactericides 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 work 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. Summary Figure 1 According to the test data, the antibacterial effect of Example 9 is the most significant, which confirms the effectiveness of the compounding scheme and achieves a bactericidal effect that exceeds that of a single component while ensuring that the aluminum alloy is not corroded.

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

[0042] In order to verify the effect of the groove edge inhibitor after deterioration 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) compounding 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 prepared in Comparative Example 2 and Examples 10-13 in Table 2 were added at 0.1% to the corrupted aluminum alloy cutting fluid retrieved from the site, and the pH value before and after adding the inhibitors was tested with a pH meter. The test results are shown in Table 3.

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

[0047]

[0048]

[0049] It can be seen from the data in Table 3 that the addition of inhibitors can increase the pH value of the aluminum alloy cutting fluid to a certain extent.

[0050] Take a 7050 aluminum sheet, polish it with 180 mesh and 240 mesh sandpaper respectively, and then half-immerse it in the inhibitor of the above Examples 10-13. After immersion for 3 hours, take it out and take pictures to observe the gas phase and liquid phase corrosion of the 7050 aluminum sheet. The test results are shown in Figure 3 .

[0051] Combining Table 3 and Figure 3 The results show that the inhibitor using the combination of AMP95 special amine and fungicide in Example 13 has a significant effect on the improvement of pH value and performs best in aluminum vapor phase corrosion. Compared with other examples, the use of AMP95 special amine can not only enhance the pH of the cutting fluid, increase the alkali storage and improve the biological stability, but also effectively increase the pH value without causing corrosion to aluminum.

[0052] In order to verify the effect of the compounding ratio and addition amount of the groove edge inhibitor of the present invention on the improvement of the pH value of the cutting fluid corruption liquid and the bactericidal effect, this example adopts the compounding ratio of different special amines and bactericides, and adopts different addition amounts of groove edge inhibitors (0.3%, 0.6%, 0.9%, 1.2%), and obtains the inhibitor formula and addition ratio shown in Table 4; At the same time, the pH value of the corruption liquid with the inhibitor added is tested, and the results are shown in Table 5. In this embodiment, the corruption liquid is an emulsified cutting fluid deterioration corruption liquid, which includes, by weight: 70-80 parts of base oil, 5-7 parts of emulsified rust inhibitor, 0.5-1 parts of phosphate ester, 4-6 parts of lubricant, 1-2 parts of bactericide, 1-2 parts of organic base, 0.5-1 parts of inorganic base, 5-7 parts of emulsifier, and 0.1 parts of defoamer.

[0053] Table 4 Ratio of corrupt liquid to tank side inhibitor

[0054]

[0055]

[0056]

[0057] Table 5 pH value test of different embodiments

[0058]

[0059]

[0060] From the data in Table 5, it can be seen that adding 0.3-1.2% of the groove edge inhibitor to the deteriorated and corrupted aluminum alloy cutting fluid can increase the pH value of the cutting fluid to a certain extent, and under the condition of the same amount of groove edge inhibitor added, when the mass ratio of the special amine to the bactericide in the groove edge inhibitor is (1-3):1, the pH value is improved more significantly. It can also be seen from Table 5 that in Example 31, when the groove edge inhibitor is added to the deteriorated and corrupted aluminum alloy cutting fluid at a ratio of 1.2%, and the mass ratio of the special amine to the bactericide in the groove edge inhibitor is 3:1, the pH can be effectively increased to 8.47, reaching the ideal pH range for aluminum alloy cutting fluid processing.

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

[0062] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A groove edge inhibitor for aluminum alloy cutting fluid after degradation, characterized in that: The groove edge inhibitor comprises special amine and fungicide, and the fungicide consists of methylisothiazolinone and 1,3-bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione.

2. The groove edge inhibitor for aluminum alloy cutting fluid after degradation according to claim 1, characterized in that: The special amine is one or more of monoisopropanolamine, N-methyldiethanolamine, 2-amino-2-methyl-1-propanol and diglycolamine.

3. The groove edge inhibitor for aluminum alloy cutting fluid after degradation according to claim 1, characterized in that: The special amine is 2-amino-2-methyl-1-propanol.

4. The groove edge inhibitor for aluminum alloy cutting fluid after degradation according to any one of claims 1 to 3, characterized in that: The mass ratio of the special amine to the fungicide in the groove 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 fungicide is 1:

1.

5. A method for preparing a groove edge inhibitor for aluminum alloy cutting fluid after degradation according to any one of claims 1 to 4, characterized in that: Includes steps: Weigh the tert-amine and fungicide according to the ratio; Add the weighed special amine and fungicide into the reactor, start the heating and stirring device, stir them evenly to obtain a mixed solution; The mixed solution is filtered and then sterilized, and finally canned to obtain the tank edge inhibitor.

6. An application of the groove edge inhibitor for deteriorated aluminum alloy cutting fluid as claimed in any one of claims 1 to 4, characterized in that: The groove edge inhibitor is directly added into the liquid tank of the deteriorated and corrupted aluminum alloy cutting fluid on site.

7. The use of the groove edge inhibitor according to claim 6, characterized in that: During use, the addition amount of the groove edge inhibitor is 0.3-1.2%.

8. The use of the groove edge inhibitor according to claim 6, characterized in that: During use, the addition amount of the slot edge inhibitor was 1.2%.

9. The use of the groove edge inhibitor according to claim 6, characterized in that: During use, the addition amount of the groove edge inhibitor was 0.9%.

10. The use of the groove edge inhibitor according to claim 6, characterized in that: During use, the addition amount of the groove edge inhibitor was 0.6%.

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