A neutral flow enhancer specifically for aluminum pop can production and method of making

Abstract

This invention relates to the field of cleaning agent technology, particularly to IPC C23G1, and more specifically to a neutral flow enhancer and its preparation method specifically for the production of aluminum cans. This invention, by adding bactericides, organic acids, pH adjusters, surfactants, auxiliary wetting agents, silicone defoamers, and deionized water, yields a neutral flow enhancer that improves drying efficiency, reduces energy consumption, and contributes to improved efficiency in subsequent printing processes.

Description

Technical Field

[0001] This invention relates to the field of cleaning agent technology, particularly to IPC C23G1, and more specifically to a neutral flow enhancer and its preparation method specifically for the production of aluminum cans. Background Technology

[0002] Aluminum beverage cans, as a type of packaging that is high-strength, not easily broken, lightweight, and has good sealing properties, have seen rapid development, and domestic production of aluminum beverage cans is constantly increasing. The process of making aluminum beverage cans includes conveying aluminum materials, cup rinsing and stretching, trimming, cleaning the can body, drying, printing and decoration, necking and flanging, etc. Among these processes, cleaning the can body and drying have a significant impact on energy loss and subsequent printing.

[0003] Existing patent CN201810616070.8 discloses a rust-preventive cleaning agent for aluminum and aluminum alloys and its preparation method. It discloses an alkaline cleaning aid, including sodium tripolyphosphate, sodium pyrophosphate, sodium orthophosphate, potassium pyrophosphate, potassium orthophosphate, sodium metaphosphate, potassium carbonate, sodium carbonate, and sodium metasilicate pentahydrate. When added to the cleaning agent for cleaning, it has poor water removal film and is alkaline in pH, which can easily damage the machine.

[0004] Currently used flow enhancers for aluminum cans have three main problems: First, they contain high levels of phosphorus, which can easily lead to eutrophication of water bodies during discharge, harming the environment and increasing wastewater treatment costs. Second, excessive acidity or alkalinity in the flow enhancer system can cause volatilization during operation, leading to environmental pollution, harm to workers' health, and corrosion of machinery, reducing its lifespan and increasing costs. Third, the flow enhancer produces a weak water film, requiring high drying temperatures and consuming a lot of energy, which is not conducive to energy conservation and emission reduction.

[0005] Therefore, it is necessary to develop a neutral flow enhancer to improve the fluidity of the water film after cleaning the can, thereby reducing the drying temperature, improving drying efficiency, reducing energy consumption, and also helping to improve the efficiency of subsequent printing processes. Summary of the Invention

[0006] To address the problems in the prior art, the first aspect of this invention provides a neutral flow enhancer specifically for the production of aluminum beverage cans. The raw materials for its preparation, by mass percentage, include 1-5% bactericide, 11-20% organic acid, 1-5% pH adjuster, 5-10% surfactant, 0.5-2.0% auxiliary wetting agent, and 0.05-0.1% organosilicon defoamer.

[0007] Preferably, the bactericide includes one or more of the following: capryloyl hydroxamic acid, PESA polyepoxysuccinate, hydroxyethyl hexahydrotriazine, chlorine dioxide, triclocarban, iodopropynyl butylamine, and sodium polyacrylate.

[0008] Preferably, the organic acid includes at least two of citric acid, tartaric acid, malic acid, glycolic acid, salicylic acid, and caffeic acid.

[0009] Preferably, the mass ratio of the organic acid to the surfactant is (10-15):7; more preferably, it is 12:7.

[0010] Preferably, the mass ratio of citric acid to glycolic acid is (3-7):1; more preferably, it is 5:1.

[0011] Preferably, the pH adjuster includes ammonia; more preferably, the ammonia is 25 wt% ammonia.

[0012] In this invention, organic acids and surfactants react in a system, and by controlling their proportions to achieve a neutral pH, they are then combined with bactericides, auxiliary wetting agents, and silicone-based defoamers to further neutralize the overall pH of the system. This results in a neutral flow enhancer using fewer pH adjusters, reducing corrosive damage to instruments, increasing container lifespan, and lowering labor and instrument costs. Furthermore, the neutral system contains less acid and alkali, making it less volatile and reducing potential harm to employee health.

[0013] Preferably, the surfactant includes fatty amine polyoxyethylene ether.

[0014] Preferably, the fatty amine polyoxyethylene ether includes one or more of tallow amine polyoxyethylene ether, dodecylamine polyoxyethylene ether, and octadecylamine polyoxyethylene ether.

[0015] Preferably, the average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 2 to 10; more preferably, it is 2, 5 or 10.

[0016] In this invention, by selecting specific fatty amine polyoxyethylene ethers, especially tallow amine polyoxyethylene ethers, to form organic saponifications with organic acids, drying efficiency can be improved, resulting in lower drying temperatures and reduced energy consumption. The inventors have creatively discovered that adding tallow amine polyoxyethylene ethers to a neutral flow enhancer can form organic saponifications with organic acids. Under the action of a wetting agent, these saponifications bind water molecules, reducing the steady-state surface tension and enhancing the fluidity of the water film. This, in turn, lowers the drying temperature, improves drying efficiency, and reduces energy consumption.

[0017] By selecting tallow amine polyoxyethylene ethers with a specific average EO number, particularly tallow amine polyoxyethylene ethers with an average EO number of 10, drying efficiency has been further improved and energy consumption reduced. The inventors believe that a higher average EO number indicates weaker hydrophobicity and stronger hydrophilicity, and a suitable water-oil balance can enhance the fluidity of the water film. Long-term experiments have shown that tallow amine polyoxyethylene ethers with an average EO number of 2–10 can enhance the fluidity of the water film to a certain extent. Especially tallow amine polyoxyethylene ethers with an average EO number of 10, under water rinsing, have some of their hydrophilic groups combine with water molecules in the water film on the metal surface, enhancing the fluidity of the water film, reducing the amount of water remaining on the metal surface, and shortening the drying time. When the average EO number is 15 or 30, its hydrophilicity is too strong, failing to enhance the fluidity of the water film and improve drying efficiency.

[0018] Preferably, the auxiliary wetting agent includes alkynyl alcohol wetting agents.

[0019] Preferably, the alkynyl alcohol wetting agent includes one or more of 2,4,7,9-tetramethyl-5-decyn-4,7-diol, ethoxylated alkynyl alcohol, and 2,5-hexynyl alcohol.

[0020] Preferably, the active ingredient in the silicone defoamer is a three-dimensional siloxane; more preferably, the viscosity of the silicone defoamer is 2200-3600 cps at 25°C.

[0021] A second aspect of this invention provides a method for preparing a neutral flow enhancer specifically for the production of aluminum beverage cans, comprising the following steps:

[0022] S1: Add deionized water, stir and heat to 50-70℃;

[0023] S2: Add fatty amine polyoxyethylene ether and organic acid sequentially to deionized water at 50-70℃, and stir for 50-80 minutes to form organic saponification.

[0024] S3: After the organic saponification is formed, lower the temperature to 40°C and keep it warm. Then add bactericide, pH adjuster, alkynyl alcohol wetting agent and silicone defoamer in sequence, and stir for 20 to 50 minutes to make the solution uniform.

[0025] S4: Turn off the heating, stir until cooled to room temperature, and set aside.

[0026] Preferably, the organic saponified product is tallow amine polyoxyethylene ether-citric acid soap and tallow amine polyoxyethylene ether-glycolic acid soap.

[0027] The reaction formula for the tallow amine polyoxyethylene ether-citric acid soap is as follows:

[0028]

[0029] The reaction formula for the tallow amine polyoxyethylene ether-glycolic acid soap is as follows:

[0030]

[0031] In this invention, different ratios of citric acid and glycolic acid are reacted with surfactants to form different organic soap blends, thereby improving the drying effect. The inventors believe that by reacting different ratios of citric acid and glycolic acid with tallow amine polyoxyethylene ether, specific ratios of tallow amine polyoxyethylene ether-citric acid soap and tallow amine polyoxyethylene ether-glycolic acid soap are formed. The blending of these two organic soaps creates mixed micelles, allowing moisture on the metal surface and trace residues from previous processes to form a stable two-phase dispersion system. This removes moisture and residues from the metal surface, while simultaneously reducing the steady-state surface tension, decreasing residual moisture, shortening drying time, and improving drying efficiency.

[0032] Beneficial effects

[0033] 1. In this invention, by selecting specific fatty amine polyoxyethylene ethers, especially tallow amine polyoxyethylene ethers, to form organic saponifications with organic acids, the drying efficiency can be improved, resulting in lower drying temperatures and reduced energy consumption.

[0034] 2. In this invention, tallow amine polyoxyethylene ether with a specific average EO number is selected, especially tallow amine polyoxyethylene ether with an average EO number of 10, which further improves drying efficiency and reduces energy consumption costs.

[0035] 3. In this invention, specific organic acids (citric acid and glycolic acid) are used to react with tallow amine polyoxyethylene ether in a specific ratio to form corresponding organic soaps, forming tallow amine polyoxyethylene ether-citric acid soap and tallow amine polyoxyethylene ether-glycolic acid soap complexes. With the assistance of alkynyl alcohol wetting agents, their wetting performance is improved. When processing metals, they can remove residual impurities on the metal surface, reduce the coverage area of ​​the water film, thereby reducing the drying time and improving the drying effect.

[0036] 4. In this invention, organic acids and surfactants react in the system, and by controlling their proportions to achieve a neutral pH, they are then combined with bactericides, auxiliary wetting agents, and silicone defoamers to make the overall system pH more neutral. Using less pH adjuster, a neutral flow enhancer is obtained, reducing corrosive damage to instruments, increasing container lifespan, and lowering labor and instrument costs. Simultaneously, the neutral system contains less acid and alkali, making it less volatile and reducing harm to employee health.

[0037] 5. In this invention, by selecting phosphorus-free raw materials, the wastewater treatment steps are reduced, preventing eutrophication pollution of water bodies. Compared with commercially available products, this invention, by adding bactericides, organic acids, pH adjusters, surfactants, auxiliary wetting agents, silicone defoamers, and deionized water, yields a neutral flow enhancer with higher drying efficiency, lower energy consumption, and significantly improved efficiency in subsequent printing processes. Detailed Implementation

[0038] Example 1

[0039] The first aspect of this embodiment provides a neutral flow enhancer specifically for the production of aluminum beverage cans. The raw materials for its preparation, by mass percentage, are 2% bactericide, 12% organic acid, 0.2% pH adjuster, 7% surfactant, 1.5% auxiliary wetting agent, 0.1% organosilicon defoamer, and deionized water to make up the balance.

[0040] The bactericide is hydroxyethyl hexahydrotriazine.

[0041] The hydroxyethyl hexahydrotriazine was purchased from NIPACIDE BK of Clariant Chemicals (China) Co., Ltd.

[0042] The organic acids are citric acid and glycolic acid.

[0043] The citric acid was purchased from Sinopharm Group as citric acid monohydrate.

[0044] The glycolic acid mentioned was purchased from Sinopharm Group.

[0045] The mass ratio of citric acid to glycolic acid is 5:1.

[0046] The pH adjuster is 25 wt% ammonia.

[0047] The ammonia water was purchased from Sinopharm Group.

[0048] The surfactant is a fatty amine polyoxyethylene ether.

[0049] The fatty amine polyoxyethylene ether is tallow amine polyoxyethylene ether.

[0050] The average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 2.

[0051] The tallow amine polyoxyethylene ether was purchased from Rhodia Group's FENTACARE T02.

[0052] The auxiliary wetting agent is an alkynyl alcohol wetting agent.

[0053] The alkynyl alcohol wetting agent is 2,4,7,9-tetramethyl-5-decyn-4,7-diol.

[0054] The 2,4,7,9-tetramethyl-5-decyn-4,7-diol was purchased from Air Products Surfynol 104E.

[0055] The active ingredient in the silicone defoamer is a three-dimensional siloxane; the viscosity of the silicone defoamer is 2200-3600 cps at 25°C.

[0056] The aforementioned silicone defoamer was purchased from Mingling. HP990.

[0057] The second aspect of this embodiment provides a method for preparing a neutral flow enhancer specifically for the production of aluminum beverage cans, comprising the following steps:

[0058] S1: Add deionized water, stir and heat to 60℃;

[0059] S2: Add fatty amine polyoxyethylene ether and organic acid sequentially to deionized water at 60℃, stir for 1 hour to form organic saponification;

[0060] S3: After the organic saponification is formed, lower the temperature to 40°C and keep it warm. Then add the bactericide, pH adjuster, alkynyl alcohol wetting agent and silicone defoamer in sequence, and stir for 30 minutes to make the solution uniform.

[0061] S4: Turn off the heating and stir until cooled to 25°C. Set aside.

[0062] The organic saponified products are tallow amine polyoxyethylene ether-citric acid soap and tallow amine polyoxyethylene ether-glycolic acid soap.

[0063] Example 2

[0064] The specific implementation method of Example 2 is the same as that of Example 1, except that the fatty amine polyoxyethylene ether is tallow amine polyoxyethylene ether.

[0065] The average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 5.

[0066] The tallow amine polyoxyethylene ether was purchased from Rhodia Group's FENTACARE T05.

[0067] Example 3

[0068] The specific implementation method of Example 3 is the same as that of Example 1, except that the fatty amine polyoxyethylene ether is tallow amine polyoxyethylene ether.

[0069] The average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 10.

[0070] The tallow amine polyoxyethylene ether was purchased from Rhodia Group's FENTACARE T10.

[0071] Comparative Example 1

[0072] The specific implementation method of Comparative Example 1 is the same as that of Example 1, except that the mass percentage of pH adjuster in the raw materials is 0.8% and the mass percentage of surfactant is 1%.

[0073] The pH adjuster is 25 wt% ammonia.

[0074] The ammonia water was purchased from Sinopharm Group.

[0075] The surfactants mentioned include fatty amine polyoxyethylene ethers.

[0076] The fatty amine polyoxyethylene ether is tallow amine polyoxyethylene ether.

[0077] The average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 2.

[0078] The tallow amine polyoxyethylene ether was purchased from Rhodia Group's FENTACARE T02.

[0079] Comparative Example 2

[0080] The specific implementation method of Comparative Example 2 is the same as that of Example 1, except that the mass percentage of the organic acid is 12%; the organic acid is citric acid and glycolic acid; and the mass ratio of citric acid to glycolic acid is 1:1. The citric acid was purchased from Sinopharm Group as citric acid monohydrate. The glycolic acid was purchased from Sinopharm Group as glycolic acid.

[0081] Comparative Example 3

[0082] The specific implementation method of Comparative Example 3 is the same as that of Example 1, except that the mass percentage of the auxiliary wetting agent in the raw materials is 0.1%; and the auxiliary wetting agent is an alkynol wetting agent.

[0083] The alkynyl alcohol wetting agent is 2,4,7,9-tetramethyl-5-decyn-4,7-diol.

[0084] The 2,4,7,9-tetramethyl-5-decyn-4,7-diol was purchased from Air Products Surfynol 104E.

[0085] Comparative Example 4

[0086] The specific implementation method of Comparative Example 4 is the same as that of Example 1, except that the fatty amine polyoxyethylene ether is coconut oil alkylamine polyoxyethylene ether. The coconut oil alkylamine polyoxyethylene ether was purchased from AkzoNobel ETHOMEEN C / 15.

[0087] Performance testing

[0088] 1. Phosphorus content test

[0089] Test method: ICP test (inductively coupled plasma).

[0090] The phosphorus content of Examples 1-3, Comparative Examples 1-4, and commercially available products was measured using the ICP test method, and the results are shown in Table 1.

[0091] Results show that, as can be seen from the ICP test of phosphorus content, compared with commercially available products (UNICOAT RA76), the product described in this invention does not contain phosphorus, is more environmentally friendly, and does not pose a potential hazard of eutrophication of water bodies.

[0092] Table 1

[0093]

[0094] 2. pH test

[0095] Test method: 0.02% aqueous solutions were prepared from Examples 1-3, Comparative Examples 1-4, and commercially available neutral flow enhancers. The pH values ​​of the different aqueous solutions were measured using a pH meter. The results are shown in Table 2.

[0096] Results show that the pH of the neutral flow enhancer in Examples 1-3 of this invention is neutral.

[0097] Table 2

[0098]

[0099] 3. Steady-state surface tension test

[0100] Test method: The surface tension of 0.02% aqueous solutions prepared from Examples 1-3, Comparative Examples 1-4, and commercially available products was tested under steady-state conditions using a Kruss BP100 surface tension meter. The results are shown in Table 3.

[0101] Results show that the neutral flow enhancers prepared in Examples 1-3 all have low steady-state surface tension and better surface activity, thus exhibiting better flowability and achieving faster drying speed.

[0102] Table 3

[0103]

[0104] 4. Corrosion resistance test

[0105] Test sample: 3014H19 aluminum sheet, dimensions 1.0x25x35mm;

[0106] Test solutions: Prepare 0.02% test solutions from Examples 1-3, Comparative Examples 1-4, and commercially available neutral flow enhancers;

[0107] Test method: The aluminum sheet was cleaned sequentially with petroleum ether and deionized water, dried and weighed, then placed in the test solution and sealed, and placed in a 45℃ oven for 72 hours. After the 72 hours, the aluminum sheet was removed, rinsed with deionized water, dried and weighed again, and the weight loss of the aluminum sheet was calculated. The greater the weight loss, the more severe the corrosion. The results are shown in Table 4.

[0108] Results show that the neutral flow enhancers prepared in Examples 1-3 have less weight loss compared to commercially available products and Comparative Examples 1-4.

[0109] Table 4

[0110]

[0111] 5. Water film drying speed test

[0112] Test sample: 3014H19 aluminum sheet, dimensions 1.0x25x35mm;

[0113] Test solutions: Prepare 0.02% test solutions from Examples 1-3, Comparative Examples 1-4, and commercially available neutral flow enhancers;

[0114] Test method: The aluminum sheet was cleaned sequentially with petroleum ether and deionized water, dried, and then placed in the test solution for 1 minute. After removal, it was placed in a wet balance and dried and weighed at 180°C. The final drying time (until the weight no longer changes) was recorded. The shorter the required drying time, the better the effect. The results are shown in Table 5.

[0115] Results show that the neutral flow enhancers prepared in Examples 1 to 33 all have significantly improved performance compared to commercially available products. Furthermore, Example 3 shows the best results.

[0116] Table 5

[0117]

Claims

1. A neutral flow enhancer specifically for the production of aluminum beverage cans, characterized in that, The raw materials for its preparation, by mass percentage, include 1-5% bactericide, 11-20% organic acid, 1-5% pH adjuster, 5-10% surfactant, 0.5-2.0% auxiliary wetting agent, and 0.05-0.1% organosilicon defoamer; the surfactant includes fatty amine polyoxyethylene ether. The organic acid is citric acid and glycolic acid, and the mass ratio of citric acid to glycolic acid is (3-7):1; The fatty amine polyoxyethylene ether is tallow amine polyoxyethylene ether; the average EO (polyoxyethylene) number of the tallow amine polyoxyethylene ether is 2, 5 or 10.

2. The neutral flow enhancer specifically for the production of aluminum beverage cans according to claim 1, characterized in that, The bactericide includes one or more of the following: capryloyl hydroxamic acid, PESA polyepoxysuccinate, hydroxyethyl hexahydrotriazine, chlorine dioxide, triclocarban, iodopropynyl butylamine, and sodium polyacrylate.

3. The neutral flow enhancer specifically for the production of aluminum beverage cans according to claim 1, characterized in that, The pH adjuster mentioned includes ammonia.

4. The neutral flow enhancer for producing aluminum beverage cans according to claim 1, characterized in that, The auxiliary wetting agents include alkynyl alcohol wetting agents.

5. The neutral flow enhancer for producing aluminum beverage cans according to claim 4, characterized in that, The alkynyl alcohol wetting agent includes one or more of 2,4,7,9-tetramethyl-5-decyn-4,7-diol, ethoxylated alkynyl alcohol, and 2,5-hexynyl alcohol.

6. The neutral flow enhancer for producing aluminum beverage cans according to claim 1, characterized in that, The active ingredient in the organosilicon defoamer is a three-dimensional siloxane.

7. The method for preparing a neutral flow enhancer specifically for producing aluminum beverage cans according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1: Add deionized water, stir and heat to 50-70℃; S2: Add fatty amine polyoxyethylene ether and organic acid sequentially to deionized water at 50-70℃, and stir for 50-80 minutes to form organic saponification. S3: After the organic saponification is formed, lower the temperature to 40°C and keep it warm. Then add bactericide, pH adjuster, alkynyl alcohol wetting agent and silicone defoamer in sequence, and stir for 20 to 50 minutes to make the solution uniform. S4: Turn off the heating, stir until cooled to room temperature, and set aside.

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