Composite additive for water-soluble quenching medium and preparation method thereof

Abstract

The invention discloses a composite additive for a water-soluble quenching medium and a preparation method of the composite additive. The composite additive is prepared from the following components in parts by weight: 10 to 20 parts of polyisobutene maleic anhydride, 7 to 20 parts of polyvinyl caprolactam, 1.5 to 3.5 parts of polyacrylamide, 5 to 9 parts of organic alcohol amine, 0.5 to 0.7 part of an antirust agent, 0.5 to 0.9 part of a bactericidal mildew preventive, 0.3 to 0.5 part of a de-foaming agent and 30 to 50 parts of water. The composite additive can be efficiently mixed and dissolved with a traditional water-soluble quenching medium, the water-soluble quenching medium is promoted to achieve control over the low-temperature cooling speed and the lower characteristic temperature in the quenching technological process, and therefore the application range of the water-soluble quenching medium is widened, the quality of a quenched workpiece is improved, and the service life of the workpiece is prolonged. The composite additive disclosed by the invention not only solves the problem of low characteristic temperature of the existing water-soluble quenching medium, but also can enable the water-soluble quenching medium to keep proper maximum cooling speed and high characteristic temperature, and finally shows the cooling performance close to that of quenching oil.

Description

Technical Field

[0001] This invention relates to a composite additive for water-soluble quenching media, and also to a method for preparing the above-mentioned composite additive. Background Technology

[0002] For a long time, oil-based quenching media have been the mainstream choice in the industrial field due to their moderate cooling characteristics and good wetting ability. These media are based on mineral oil, supplemented with small amounts of functional additives such as antioxidants and detergent-dispersants, which enhance the stability of the base oil while improving its cooling uniformity and heat exchange efficiency. However, with the pursuit of green manufacturing, traditional oil-based quenching media have revealed many drawbacks: firstly, they are difficult to biodegrade, and leaks can easily cause long-term soil pollution; secondly, they have a low flash point, posing a fire hazard, especially in high-temperature operating environments; and thirdly, during use, localized overheating can generate large amounts of hydrocarbon-containing fumes, which not only harm the health of operators but may also cause air quality problems. These problems seriously restrict their sustainable application in modern manufacturing. To address these challenges, water-soluble polymer solutions are gradually emerging due to their unique physicochemical properties. Water-soluble quenching fluids are usually composed of polymers dissolved in water. By precisely controlling the solution concentration, the cooling rate curve can be flexibly adjusted to simulate or even surpass the cooling effect of some oil-based media. Compared to traditional mineral oil, water-soluble quenching fluids exhibit significant advantages: First, they completely eliminate the risk of flammability, significantly reducing the safety requirements of the production site; second, they have good environmental compatibility, and wastewater treatment is relatively simple, meeting clean production standards; third, the cooling characteristics can be customized through formula design to meet the quenching needs of workpieces of different materials and shapes.

[0003] Water-soluble quenching media are typically composed of polymers such as PAG, ACR, and PVP. Their cooling performance curves show that the upper characteristic temperature and maximum cooling rate can generally be adjusted to partially achieve or approach the cooling performance of quenching oil by regulating the viscosity of the polymer solution. However, extensive industrial applications have demonstrated that the lower characteristic temperature of these water-soluble polymer quenching media usually cannot reach or approach the lower characteristic temperature of quenching oil, especially compared to high-viscosity isothermal quenching oils, where the difference in lower characteristic temperature is even greater. This, to some extent, limits the application scenarios of water-soluble polymer quenching media. Summary of the Invention

[0004] Objective of this invention: The objective of this invention is to provide a composite additive that can be added to a water-soluble quenching medium, which can effectively improve the cooling performance of the water-soluble polymer quenching medium, enabling it to possess the cooling performance of quenching oil, especially so that the lower characteristic temperature of the cooling curve of the water-soluble polymer quenching medium can reach the lower characteristic temperature of quenching oil; another objective of this invention is to provide a method for preparing the above-mentioned composite additive.

[0005] Technical solution: The composite additive of the present invention is composed of the following components in parts by weight: 10-20 parts of polyisobutylene maleic anhydride, 7-20 parts of polyvinyl caprolactam, 1.5-3.5 parts of polyacrylamide, 5-9 parts of organic alcohol amine, 0.5-0.7 parts of rust inhibitor, 0.5-0.9 parts of bactericide and mildew inhibitor, 0.3-0.5 parts of defoamer, and 30-50 parts of RO water.

[0006] The polyisobutylene maleic anhydride has a weight-average molecular weight of 100,000 to 200,000; the polyvinylcaprolactam has a weight-average molecular weight of 10,000 to 50,000; the mass ratio of polyisobutylene maleic anhydride to polyvinylcaprolactam is 1 to 1.5:1; and the polyacrylamide has a weight-average molecular weight of 200,000 to 300,000. The organic alcohol amine is diethanolamine or triethanolamine; the bactericide and fungicide is benzoisothiazolinone (BIT) or triazine (BK) bactericide; the defoamer is emulsified silicone oil or polyether defoamer; and the rust inhibitor is one of borax, sodium nitrite, or sodium carbonate.

[0007] The mechanism by which this invention achieves its technical effect is as follows: by regulating the thickness and time of the vapor film during quenching through hydrophobic polymers (polyisobutylene maleic anhydride and polyvinyl caprolactam) within the system, a cooling behavior similar to quenching oil is achieved. The upper characteristic temperature point of water-soluble polymer quenching fluids is typically highly correlated with the solution's viscosity. Traditional water-soluble polymer quenching fluids control the upper characteristic temperature by adjusting the solution's viscosity; the higher the viscosity, the lower the upper characteristic temperature point. However, increasing the viscosity cannot change the lower characteristic temperature point of the aqueous solution quenching fluid. The composite additives of this invention, when added to traditional water-soluble polymer quenching fluids, have a minimal impact on the quenching fluid, meaning they do not significantly alter its viscosity. Therefore, the upper characteristic temperature point of the quenching fluid remains unaffected after the addition of the composite additives.

[0008] The preparation method of the above-mentioned composite additive is as follows: Mix the prescribed amount of water and polyisobutylene maleic anhydride, adjust the stirring speed to 60-80 rpm, and the temperature to 70-90℃. After stirring for 2-3 hours, add the prescribed amount of organic alcohol amine and continue stirring for 1-2 hours. Then, slowly add the prescribed amounts of polyvinylcaprolactam and polyacrylamide to the above mixture over 2-2.5 hours while stirring. After the addition is complete, continue the reaction for 1-1.5 hours. Finally, add the prescribed amounts of rust inhibitor, bactericide, mildew inhibitor, and defoamer, and continue stirring for 0.5-1 hour. Then, slowly cool to room temperature and stop stirring to obtain the composite additive.

[0009] Polyvinyl caprolactam has a large number of amide groups on its molecular chain. These groups can be entangled with the hydroxyl or amide groups at the end of the hydrolyzed polyisobutylene maleic anhydride through hydrogen bonding, thereby wrapping the hydrophobic end inside and exposing the hydrophilic skeleton on the outside, forming a core-shell structure, so as to achieve the purpose of forming a nanoscale dispersion in aqueous solution. Therefore, the order of material addition has an important influence on the formation of subsequent water-based dispersions.

[0010] The above-mentioned composite additive is added to the water-soluble quenching medium at 8-10% of the mass of the water-soluble quenching medium and mixed evenly to obtain an oil-like water-soluble quenching medium; wherein, the water-soluble quenching medium is a water-soluble PAG quenching medium.

[0011] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The composite additive of the present invention can be efficiently miscible with traditional water-soluble quenching media, promoting the control of low-temperature cooling rate and lower characteristic temperature of water-soluble quenching media during the quenching process, thereby expanding the application range of water-soluble quenching media and improving the quality of quenched workpieces. The composite additive of the present invention not only solves the problem of lower characteristic temperature of existing water-soluble quenching media, but also enables water-soluble quenching media to maintain a suitable maximum cooling rate and upper characteristic temperature, ultimately exhibiting cooling performance close to that of quenching oil. Attached Figure Description

[0012] Figure 1 The cooling characteristic curves are shown for the oil-like water-soluble quenching medium obtained based on the composite additive in Example 1 and the PAG quenching fluid (KR6480) before the addition of the composite additive. Figure 2 The cooling characteristic curves are shown for the oil-like water-soluble quenching medium obtained based on the composite additive in Example 2 and the PAG quenching fluid (KR6480) before the addition of the composite additive. Figure 3 The cooling characteristic curves are shown for the oil-like water-soluble quenching medium obtained based on the composite additive in Example 3 and the PAG quenching fluid (KR6480) before the addition of the composite additive. Figure 4 The cooling characteristic curve of quenching oil KR498; Figure 5 The cooling characteristic curves of quenching oil KR105 are shown. Detailed Implementation

[0013] Example 1 The composite additive of the present invention is composed of the following components in parts by weight: 10 parts of polyisobutylene maleic anhydride (weight average molecular weight of 100,000), 7 parts of polyvinyl caprolactam (weight average molecular weight of 10,000), 1.5 parts of polyacrylamide (weight average molecular weight of 200,000), 5 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0014] The above-mentioned composite additive was prepared by the following method: 50 parts by weight of RO water and 10 parts by weight of polyisobutylene maleic anhydride were added to a jacketed water-cooled reactor, the temperature was raised to 70°C, and the stirring was started at 60 rpm. After stirring for 2 hours, 5 parts by weight of triethanolamine were added and stirring was continued for 1 hour. Then, 7 parts by weight of polyvinyl caprolactam and 1.5 parts by weight of polyacrylamide were slowly added to the above reactor over 2 hours while stirring. After the addition was completed, the reaction was continued for 1 hour until the reaction was complete. Finally, 0.5 parts by weight of sodium nitrite, 0.5 parts by weight of BK bactericide and 0.3 parts by weight of emulsified silicone oil were added and stirring was continued for 0.5 hours until the mixture was uniform. The mixture was cooled to room temperature and stirring was stopped to obtain the composite additive.

[0015] The composite additive of Example 1 was added to the water-soluble PAG quenching medium (the commercial model of the water-soluble PAG quenching medium is water-soluble quenching medium KR6480) at 10% of the mass of the water-soluble quenching medium and mixed evenly to obtain an oil-like water-soluble PAG quenching medium.

[0016] Example 2 The composite additive of the present invention is composed of the following components in parts by weight: 15 parts of polyisobutylene maleic anhydride (weight average molecular weight of 200,000), 10 parts of polyvinyl caprolactam (weight average molecular weight of 30,000), 2.5 parts of polyacrylamide (weight average molecular weight of 250,000), 7 parts of triethanolamine, 0.7 parts of sodium nitrite, 0.9 parts of BK bactericide, 0.5 parts of emulsified silicone oil, and 40 parts of RO water.

[0017] The above-mentioned composite additive was prepared by the following method: 40 parts by weight of RO water and 15 parts by weight of polyisobutylene maleic anhydride were added to a jacketed water-cooled reactor, the temperature was raised to 80°C, and the stirring was started at 70 rpm. After stirring for 2.5 hours, 7 parts by weight of triethanolamine were added and stirring was continued for 1 hour. Then, 10 parts by weight of polyvinyl caprolactam and 2.5 parts by weight of polyacrylamide were slowly added to the above reactor over 2.3 hours while stirring. After the addition was completed, the reaction was continued for 1.5 hours until the reaction was complete. Finally, 0.7 parts by weight of sodium nitrite, 0.9 parts by weight of BK bactericide and 0.5 parts by weight of emulsified silicone oil were added and stirring was continued for 1 hour until the mixture was uniform. The mixture was cooled to room temperature and stirring was stopped to obtain the composite additive.

[0018] The composite additive of Example 2 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that of Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain an oil-like water-soluble PAG quenching medium.

[0019] Example 3 The composite additive of the present invention is composed of the following components in parts by weight: 20 parts of polyisobutylene maleic anhydride (weight average molecular weight of 200,000), 20 parts of polyvinyl caprolactam (weight average molecular weight of 50,000), 3.5 parts of polyacrylamide (weight average molecular weight of 300,000), 9 parts of triethanolamine, 0.6 parts of sodium nitrite, 0.8 parts of BK bactericide, 0.5 parts of emulsified silicone oil, and 30 parts of RO water.

[0020] The above-mentioned composite additive was prepared by the following method: 30 parts by weight of RO water and 20 parts by weight of polyisobutylene maleic anhydride were added to a jacketed water-cooled reactor, heated to 90°C, and stirred at 80 rpm for 2.5 hours. Then, 9 parts by weight of triethanolamine were added and stirred for another 1.5 hours. Next, 20 parts by weight of polyvinylcaprolactam and 3.5 parts by weight of polyacrylamide were slowly added to the reactor over 2.5 hours while stirring. After the addition was complete, the reaction was continued for another 1.5 hours until the reaction was complete. Finally, 0.6 parts by weight of sodium nitrite, 0.8 parts by weight of BK bactericide, and 0.5 parts by weight of emulsified silicone oil were added and stirred for another hour until the mixture was homogeneous. The mixture was then cooled to room temperature and stirring was stopped to obtain the composite additive.

[0021] The composite additive of Example 3 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that of Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain an oil-like water-soluble PAG quenching medium.

[0022] Comparative Example 1 A composite additive is composed of the following components in parts by weight: 10 parts of polyisobutylene maleic anhydride (weight average molecular weight of 100,000), 1.5 parts of polyacrylamide (200,000), 5 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0023] The above-mentioned composite additive was prepared by the following method: 50 parts by weight of RO water and 10 parts by weight of polyisobutylene maleic anhydride were added to a jacketed water-cooled reactor, the temperature was raised to 70°C, and the stirring was started at 60 rpm. After stirring for 2 hours, 5 parts by weight of triethanolamine were added and stirring was continued for 1 hour. Then, 1.5 parts by weight of polyacrylamide were slowly added to the above reactor over 0.5 hours while stirring. After the addition was completed, the reaction was continued for 0.5 hours until the reaction was complete. Finally, 0.5 parts by weight of sodium nitrite, 0.5 parts by weight of BK bactericide and 0.3 parts by weight of emulsified silicone oil were added and stirring was continued for 0.5 hours until the mixture was uniform. The mixture was then cooled to room temperature and stirring was stopped to obtain the composite additive.

[0024] The composite additive of Comparative Example 1 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as in Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain the water-soluble PAG quenching medium.

[0025] Comparative Example 2 A composite additive is composed of the following components in parts by weight: 10 parts of polyisobutylene maleic anhydride (weight average molecular weight of 50,000), 7 parts of polyvinyl caprolactam (weight average molecular weight of 5,000), 1.5 parts of polyacrylamide (200,000), 5 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0026] The preparation method of the composite additive in Comparative Example 2 is the same as that in Example 1.

[0027] The composite additive of Comparative Example 2 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that in Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain the water-soluble PAG quenching medium.

[0028] Comparative Example 3 A composite additive is composed of the following components in parts by weight: 20 parts of polyisobutylene maleic anhydride (weight average molecular weight of 100,000), 10 parts of polyvinyl caprolactam (weight average molecular weight of 10,000), 2.0 parts of polyacrylamide (weight average molecular weight of 200,000), 7 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0029] The preparation method of the composite additive in Comparative Example 3 is the same as that in Example 1.

[0030] The composite additive of Comparative Example 3 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that in Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain the water-soluble PAG quenching medium.

[0031] Comparative Example 4 A composite additive is composed of the following components in parts by weight: 10 parts of polyisobutylene maleic anhydride (weight average molecular weight of 100,000), 7 parts of polyvinylpyrrolidone (weight average molecular weight of 10,000), 1.5 parts of polyacrylamide (weight average molecular weight of 200,000), 5 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0032] The preparation method of the composite additive in Comparative Example 4 is the same as that in Example 1.

[0033] The composite additive of Comparative Example 4 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that in Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain the water-soluble PAG quenching medium.

[0034] Comparative Example 5 The composite additive of the present invention is composed of the following components in parts by weight: 10 parts of polyisobutylene maleic anhydride (weight average molecular weight of 100,000), 7 parts of polyvinyl caprolactam (weight average molecular weight of 10,000), 1.5 parts of polyacrylamide (weight average molecular weight of 200,000), 5 parts of triethanolamine, 0.5 parts of sodium nitrite, 0.5 parts of BK bactericide, 0.3 parts of emulsified silicone oil, and 50 parts of RO water.

[0035] The above-mentioned composite additive was prepared by the following method: 50 parts by weight of RO water and 7 parts by weight of polyvinyl caprolactam were added to a jacketed water-cooled reactor, the temperature was raised to 70°C, and the stirring was started at 60 rpm. After stirring for 2 hours, 5 parts by weight of triethanolamine were added and stirring was continued for 1 hour. Then, 10 parts by weight of polyisobutylene maleic anhydride and 1.5 parts by weight of polyacrylamide were slowly added to the above reactor over 2 hours while stirring. After the addition was completed, the reaction was continued for 1 hour until the reaction was complete. Finally, 0.5 parts by weight of sodium nitrite, 0.5 parts by weight of BK bactericide and 0.3 parts by weight of emulsified silicone oil were added and stirring was continued for 0.5 hours until the mixture was uniform. The mixture was cooled to room temperature and stirring was stopped to obtain the composite additive.

[0036] The composite additive of Comparative Example 5 was added to the water-soluble PAG quenching medium (the type of water-soluble PAG quenching medium is the same as that in Example 1) at 10% of the mass of the water-soluble quenching medium, and mixed evenly to obtain the water-soluble PAG quenching medium.

[0037] The water-soluble PAG quenching media containing composite additives prepared in Examples 1-3 and Comparative Examples 1-5 were prepared into 15wt% working solutions (diluted with deionized water) according to GB / T 30823, and their cooling performance was then tested. The test results are shown in Table 1.

[0038] Table 1

[0039] As shown in Table 1, the quenching fluids obtained in Examples 1 and 2 have cooling characteristics similar to those of ultra-fast quenching oil, and belong to the category of oil-based quenching fluid additives (the cooling rate at 300℃ is similar). The quenching fluid obtained in Example 3 has cooling characteristics similar to those of isothermal quenching oil (the cooling rate at 300℃ is basically the same).

[0040] pass Figures 1-3 It can be seen that the composite additive of the present invention can effectively improve the cooling performance of water-soluble PAG quenching medium, giving it the cooling performance of quenching oil, especially in regulating the low-temperature cooling rate of water-soluble PAG quenching medium.

Claims

1. A composite additive for water soluble quenching media, characterized in that, The polyisobutylene maleic anhydride, the polyvinyl caprolactam, the polyacrylamide, the organic alcohol amine, the antirust agent, the bacteriostatic and mildew-proof agent, the defoaming agent and the water are respectively 10-20 parts, 7-20 parts, 1.5-3.5 parts, 5-9 parts, 0.5-0.7 parts, 0.5-0.9 parts, 0.3-0.5 parts and 30-50 parts by weight.

2. The composite additive of claim 1, wherein: The weight average molecular weight of the polyisobutylene maleic anhydride is 100000-200000; the weight average molecular weight of the polyvinyl caprolactam is 10000-50000.

3. The composite additive of claim 1, wherein: The mass ratio of the polyisobutylene maleic anhydride to the polyvinyl caprolactam is 1-1.5:

1.

4. The composite additive of claim 1, wherein: The weight average molecular weight of the polyacrylamide is 200000-300000.

5. The composite additive of claim 1, wherein: The organic alcohol amine is diethanolamine or triethanolamine.

6. The composite additive of claim 1, wherein: The bacteriostatic and mildew-proof agent is benzisothiazolinone or s-triazine bactericide.

7. The composite additive of claim 1, wherein: The defoaming agent is emulsified silicone oil or polyether defoaming agent.

8. The composite additive of claim 1, wherein: The antirust agent is one of borax, sodium nitrite or sodium carbonate.

9. The composite additive of claim 1, wherein: The water-soluble quenching medium, the adding amount of the composite additive is 8-10% of the mass of the water-soluble quenching medium.

10. The method of preparing the composite additive of claim 1, characterized in that, Specifically, the formula amount of water and polyisobutylene maleic anhydride are mixed, the stirring speed is adjusted to 60-80 rpm, the temperature is 70-90℃, and after stirring for 2-3h, the formula amount of organic alcohol amine is added, and the stirring is continued for 1-2h; then the formula amount of polyvinyl caprolactam and polyacrylamide is slowly added to the above mixture within 2-2.5h, and the stirring is continued after the addition is completed for 1-1.5h; finally, the formula amount of antirust agent, bacteriostatic and mildew-proof agent and defoaming agent is added, and the stirring is continued for 0.5-1h, then slowly reduced to room temperature, and the stirring is stopped, and the composite additive is obtained.

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