Cleaning agent for two-piece aluminum pot, diluted solution of cleaning agent and cleaning method using cleaning agent

Abstract

The invention relates to a cleaning agent for a two-piece aluminum pot and also relates to a diluted solution of the cleaning agent. The invention further relates to a cleaning method for cleaning the two-piece type aluminum tank by using the cleaning agent or the diluted solution.

Description

Technical Field

[0001] This invention relates to a cleaning agent for two-piece aluminum cans, and also to a diluted solution of said cleaning agent. The invention further relates to a cleaning method for cleaning two-piece aluminum cans using the cleaning agent or diluted solution of this invention. Background Technology

[0002] Two-piece aluminum cans are widely used for packaging substances such as food, beverages, and alcohol because they are highly corrosion-resistant, lightweight, and easy to recycle. In the production line of two-piece cans, can cleaning is a crucial step. This step cleans the cans, thoroughly removing contaminants from previous steps, and prepares them for the next stage.

[0003] Existing cleaning agents used in two-piece tank production have the following disadvantages: for example, high operating temperatures (such as 60°C). o (C or higher), which leads to high energy consumption and high foaming performance, requiring more water to rinse the detergent, resulting in more wastewater.

[0004] Therefore, there is a need in the art to develop a cleaning agent that can operate at lower temperatures, such as 45-55°C. o C, especially about 50 o C, and has low foaming properties and fast cleaning speed, while achieving the desired cleaning effect. Summary of the Invention

[0005] After in-depth research, the inventors discovered that the desired cleaning agent can be obtained by combining two specific nonionic surfactants.

[0006] In a first aspect of the invention, a cleaning agent for two-piece aluminum cans is provided, wherein the cleaning agent comprises: (a) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene ethers, (b) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene polyoxypropylene ethers, wherein the polyoxyethylene polyoxypropylene ether portion has a total of ethylene oxide (EO) units and propylene oxide (PO) units in the range of 10 to 17. (c) Sulfuric acid, and (d) Water.

[0007] In a second aspect of the invention, a diluted solution of the cleaning agent of the invention is provided, and the diluted solution has a free acid value of 7 to 20, preferably 8 to 15.

[0008] In a third aspect of the invention, a cleaning method for cleaning two-piece aluminum cans is provided, comprising the step of spraying a diluted solution of the invention onto the two-piece aluminum can, and the cleaning is carried out at a temperature of 45 to 55°C, particularly about 50°C.

[0009] The cleaning agent and its diluted solution of the present invention have at least the following advantages: (i) at low temperatures such as 45 to 55 o C, especially about 50 o Cleaning of two-piece aluminum cans under C-shaped conditions to achieve the desired cleaning effect; (ii) Clean the tank at a relatively fast speed; and (iii) Low foaming during cleaning operations. Detailed Implementation

[0010] The invention is described in more detail in the following paragraphs. Unless explicitly indicated to the contrary, each aspect thus described may be combined with any one or more other aspects. In particular, any feature indicated as preferred or advantageous may be combined with any one or more other features indicated as preferred or advantageous.

[0011] The terms “about” and “approximately” used in conjunction with numerical values ​​in this article refer to values ​​of ±5%, preferably ±2%.

[0012] Component (a): One or more nonionic surfactants selected from fatty alcohol polyoxyethylene ethers Component (a) "selected from one or more nonionic surfactants of fatty alcohol polyoxyethylene ether" is the basic component of the cleaning agent of the present invention.

[0013] In this context, the terms “component(a)” and “surfactant(a)” refer to the same substance and can be used interchangeably.

[0014] The inventors of this invention have surprisingly discovered that the use of a combination of fatty alcohol polyoxyethylene ether (preferably linear fatty alcohol polyoxyethylene ether) and a specific surfactant selected from fatty alcohol polyoxyethylene polyoxypropylene ethers as described in the context is important for achieving the desired technical effect, namely, at low temperatures such as 45°C. o C to 55 o C, especially around 50 o It can clean two-piece aluminum cans under C-section and features low foaming properties and fast cleaning speed.

[0015] The term “fatty alcohol polyoxyethylene ether” has its conventional meaning in the art as a surfactant composed of a fatty alcohol moiety (which is derived from fatty alcohol) and a polyoxyethylene ether moiety (which is also called an oxyethylene (EO) unit).

[0016] Methods for producing fatty alcohol polyoxyethylene ethers are known in the art, for example, by ethoxylating the fatty alcohol with ethylene oxide. Ethylene oxide forms a repeating unit -(EO) at the hydroxyl group of the fatty alcohol. m -

[0017] Preferably, the fatty alcohol polyoxyethylene ether that can be used in surfactant (a) is a linear fatty alcohol polyoxyethylene ether.

[0018] The term "straight-chain" in the term "straight-chain fatty alcohol polyoxyethylene ether" is intended to define the chain structure of the fatty alcohol moiety, meaning that the fatty alcohol used to generate surfactant (a) has a straight-chain hydrocarbon chain. For example, the fatty alcohol moiety in surfactant (a) has the formula CH3-(CH2). n -O-.

[0019] Preferably, the fatty alcohol moiety of surfactant (a) has 12-24, more preferably 12-18 carbons, which means that the fatty alcohol used to prepare surfactant (a) is a (straight-chain) C 12 -C 24 Fatty alcohols, preferably (linear) C 12 -C 18 Fatty alcohols. The term "C" 12 -C 24 "Fat alcohols" refer to those selected from C 12 fatty alcohols, C 13 fatty alcohols, C 14 fatty alcohols, C 15 fatty alcohols, C 16 fatty alcohols, C 17 fatty alcohols, C 18 fatty alcohols, C 19 fatty alcohols, C 20 fatty alcohols, C 21 fatty alcohols, C 22 fatty alcohols, C 23 fatty alcohols and C 24 One or more fatty alcohols. Meanwhile, C 12 -C 18 Fatty alcohols have the same properties as C 12 -C 24 The same meaning applies to fatty alcohols. Preferably, the fatty alcohol portion with 12-24 carbon atoms refers to a mixture of fatty alcohols with 12-24 carbon atoms used to prepare surfactant (a). Similarly, preferably, the fatty alcohol portion with 12 to 18 carbon atoms refers to a mixture of fatty alcohols with 12 to 18 carbon atoms used to produce surfactant (a).

[0020] Preferably, the polyoxyethylene ether moiety of surfactant (a) has an EO unit number in the range of 7-12, preferably 8-10, for example, 7, 8, 9, 10, 11, or 12. In the context of this application, the EO unit number refers to an average. For example, if the EO number of surfactant (a) is 9, some molecules of surfactant (a) may contain 10 EO units, some molecules of surfactant (a) may contain 8 EO units, and some molecules of surfactant (a) may contain 9 EO units, as long as the average EO number of the entire surfactant (a) is about 9. Preferably, all molecules of surfactant (a) have an EO unit number falling within the range of 7 to 12, preferably 8 to 10.

[0021] If (straight-chain) C has a different number of EO units 12 -C 24 Mixtures of fatty alcohol polyoxyethylene ethers used as surfactants and whose average number of EO units falls in the range of 7 to 12 fall within the range of surfactants (a) of the present invention, even if some molecules of the surfactant may carry fewer than 7 and / or more than 12 EO units. In the surfactants (a) of the present application, preferably less than 5 mol%, more preferably less than 2 mol%, and most preferably 0 mol%, of the surfactant molecules (a) carry fewer than 7 EO units and / or more than 12 EO units.

[0022] Preferably, the surfactant (a) of this application may have the following formula (I): CH3-(CH2) n -O-(CH2-CH2-O) m -H (I) Where n is between 11 and 23, preferably a number in the range of 11 to 17; and m is the average number in the range of 7 to 12, preferably 8 to 10.

[0023] Based on the total weight of the cleaning agent, surfactant (a) may be included in the cleaning agent of the present invention in an amount of 1.0%-4.5% by weight, preferably 2.5%-3.5%, for example 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.0%, 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2% or 4.4%.

[0024] Component (b): One or more nonionic surfactants selected from fatty alcohol polyoxyethylene polyoxypropylene ethers. Component (b) is the basic component of the cleaning agent of the present invention.

[0025] In this context, the terms “component(b)” and “surfactant(b)” refer to the same substance and can be used interchangeably.

[0026] The term "fatty alcohol polyoxyethylene polyoxypropylene ether" has its conventional meaning in the art as a surfactant composed of a fatty alcohol moiety (derived from fatty alcohol), a polyoxyethylene ether moiety (referred to as oxyethylene (EO) unit), and a polyoxypropylene ether moiety (referred to as oxypropylene (PO) unit).

[0027] Preferably, the fatty alcohol moiety of surfactant (b) has 10 to 18, more preferably 10 to 16, carbon atoms, which means that the fatty alcohol used to produce surfactant (b) is C64-245-3 ...55-345-345-355-345-345-355 10 -C 18 Fatty alcohols, preferably C 10 -C 16 Fatty alcohols. Preferably, the fatty alcohol portion having 10 to 18 carbon atoms refers to a mixture of fatty alcohols with 10 to 18 carbon atoms used in the production of surfactant (b). Similarly, preferably, the fatty alcohol portion having 10 to 16 carbon atoms refers to a mixture of fatty alcohols with 10 to 16 carbon atoms used in the production of surfactant (b).

[0028] Importantly, the total number of EO and PO units in surfactant (b) is 10-17, preferably 10-15, more preferably 12-15, for example 10, 11, 12, 13, 14, 15, 16, 17. If the total number of EO and PO units is not within the above range, the desired effect cannot be achieved. The total number of EO and PO units is also the average as described above.

[0029] Preferably, the polyoxyethylene ether moiety of surfactant (b) has an EO unit number in the range of 6-12, preferably 6-10, more preferably 7-9, for example 5, 6, 7, 8, 9, 10, 11, or 12. In the context of this application, the EO unit number means an average. Preferably, all molecules of surfactant (b) have an EO unit number in the range of 6 to 12, preferably 6 to 10, more preferably 7 to 9.

[0030] Preferably, the polyoxypropylene ether portion of surfactant (b) has a number of PO units in the range of 3-10, more preferably 3-7, and more preferably 4-6, for example, 3, 4, 5, 6, 7, 8, 9, or 10. In the context of this application, the number of PO units refers to an average. Preferably, all molecules of surfactant (b) have a number of PO units falling within the range of 3 to 10, preferably 3 to 7, and more preferably 4 to 6.

[0031] Preferably, the ratio of EO units to PO units in surfactant (b) is between 1 and 2, more preferably between 1.1 and 1.8, for example, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9.

[0032] Based on the total weight of the cleaning agent, surfactant (b) may be included in the cleaning agent of the present invention in an amount of 2.5%-6.5% by weight, preferably 3.0%-5.5%, for example 2.6%, 2.8%, 3.0%, 3.2%, 3.4%, 3.6%, 3.8%, 4.0%, 4.2%, 4.4%, 4.6%, 4.8%, 5.0%, 5.3%, 5.5%, 5.8%, 6.0%, and 6.3%.

[0033] Preferably, based on the total weight of the cleaning agent, the total weight of the nonionic surfactant (a) and the nonionic surfactant (b) is 3.5% to 10.0% by weight, more preferably 5.0% to 8.5%, for example 3.6%, 4.0%, 4.4%, 4.8%, 5.0%, 5.4%, 5.8%, 6.0%, 6.3%, 6.5%, 6.8%, 7.0%, 7.3%, 7.5%, 7.8%, 8.0%, 8.2%, 8.5%, 9.0%, and 9.5%.

[0034] Preferably, the weight ratio (a) / (b) of the nonionic surfactant (a) to the nonionic surfactant (b) is in the range of 0.30 to 1.1, more preferably 0.55 to 1.0.

[0035] Preferably, the cleaning agent of the present invention does not contain any other surfactants besides surfactants (a) and (b), such as anionic surfactants, cationic surfactants, amphoteric surfactants, amphoteric surfactants, or other nonionic surfactants besides surfactants (a) and (b).

[0036] Component (c): Sulfuric acid Component (c) sulfuric acid is an important and essential component in the cleaning agent of this application.

[0037] Based on the total weight of the cleaning agent, sulfuric acid may be included in the cleaning agent in an amount of 25%-45%, preferably 30%-40%, such as 28%, 30%, 32%, 34%, 36%, 38%, 40%, 42%, or 44% by weight.

[0038] In addition to sulfuric acid, the cleaning agent preferably does not contain other inorganic acids, such as hydrochloric acid or phosphoric acid. The statement "does not contain other inorganic acids" means that, based on the total weight of the cleaning agent, the cleaning agent contains less than 3 wt%, preferably less than 1 wt%, and more preferably 0 wt% of other inorganic acids.

[0039] Preferably, the cleaning agent of the present invention is free of organic acids. The term "free of organic acids" means that no organic acids are intentionally added, or that the cleaning agent contains 0 wt% organic acids based on the total weight of the cleaning agent.

[0040] Preferably, the cleaning agent of the present invention is free of alkaline substances, including organic and inorganic alkalis. The term "free of alkaline substances" means that no alkaline substances are intentionally added, or that the cleaning agent contains 0 wt% alkaline substances based on the total weight of the cleaning agent.

[0041] Preferably, the cleaning agent of the present invention does not contain non-surfactant polymers. The term "non-surfactant polymer" refers to a polymer that is not used as a surfactant or is not intended to be used as a surfactant. The term "free of non-surfactant polymers" means that no non-surfactant polymers are intentionally added, or that the cleaning agent contains 0 wt% of non-surfactant polymers based on the total weight of the cleaning agent.

[0042] Component (d): Water Component (d) water is the solvent of the cleaning agent of the present invention.

[0043] The cleaning agent of the present invention does not contain any organic solvents, which means that no organic solvents are intentionally added or the content of organic solvents is zero.

[0044] Other components In addition to components (a) to (d), the cleaning agent of the present invention may also contain ferric sulfate (III), which can have a beneficial effect on subsequent treatment steps.

[0045] Based on the total weight of the cleaning agent, ferric sulfate (III) may be included in the cleaning agent in an amount of 0.1%-2.5%, preferably 0.5%-2.0%, such as 0.3%, 0.7%, 1.0%, 1.2%, 1.4%, 1.6%, 1.8%, 2.0%, 2.2%, 2.2%, or 2.4% by weight.

[0046] In a preferred embodiment, the cleaning agent of the present invention comprises components (a) to (d) and ferric sulfate (III).

[0047] dilution solution In a second aspect of this application, a diluted solution of the cleaning agent of the first aspect is provided, wherein the free acid value of the diluted solution is 7-20, preferably 8-15, for example 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19.

[0048] The diluted solution of the present invention is obtained by mixing the cleaning agent of the first aspect with water until the solution has a free acid value of 7 to 20, preferably 8 to 15.

[0049] The free acid value of the diluted solution of the present invention is determined as follows: In the presence of phenolphthalein indicator, 10 ml of the diluted solution of the present invention is titrated with 0.1 N NaOH aqueous solution until the solution turns a stable pink color (i.e., no color change within 10-15 seconds indicates that the solution has become neutral), and the milliliters of 0.1 N NaOH aqueous solution consumed are defined as the free acid value.

[0050] Typically, in order to achieve the free acid value within the above range, the cleaning agent of the first aspect is usually diluted with water to a concentration of 0.5% to 3.0% by volume.

[0051] Cleaning method In another aspect of the invention, a cleaning method for cleaning two-piece aluminum cans is provided, comprising the step of spraying a diluted solution of the present application onto the two-piece aluminum can. Prior to the spraying step, a step of diluting the cleaning agent of the first aspect with water may be performed.

[0052] In the cleaning method of this application, the cleaning operating temperature can be reduced to 45 to 55 degrees Celsius. o Temperatures within the range of C, especially around 50°C o ℃.

[0053] The methods used for cleaning two-piece aluminum cans differ from those used for cleaning traditional aluminum profiles. Methods for cleaning two-piece aluminum cans require rapid cleaning speeds; typically, two-piece aluminum cans pass through the cleaning section in no more than 2 minutes, usually 40 to 80 seconds. This necessitates a very fast cleaning agent that produces low foam. Furthermore, thousands of cans pass through the cleaning section within a minute in this method, further necessitating a rapid cleaning speed. In contrast, methods for cleaning aluminum profiles typically involve immersion in the cleaning bath for a relatively long time, such as at least 20 minutes. Therefore, the development logic for cleaning agents used for cleaning two-piece aluminum cans differs from that used for cleaning traditional aluminum profiles.

[0054] Example The following examples are intended to help those skilled in the art better understand and practice the present invention. The scope of the invention is not limited to the examples, but is defined in the appended claims. Unless otherwise stated, all parts and percentages are based on weight.

[0055] The following materials are used in the embodiments.

[0056] Test methods and evaluation criteria Water break time The water film rupture time is used to assess how quickly the tank can be cleaned, i.e., the cleaning speed of the test reagent. The laboratory test procedure is as follows: - Roll coating with a mixed oil on Q-aluminum sheets; - The sheet coated with oil at a constant speed at 50 o The cleaning agent is agitated in a diluted solution at C, wherein the diluted solution is obtained by diluting the cleaning agent with water to a free acid value of 10, and the free acid value is determined according to the aforementioned method; - Visually inspect whether the water film formed on the sheet is uniform; - Record the time it takes for a uniform water film to form on the sheet as the water film rupture time.

[0057] The lower the water film breakup time, the better the cleaning agent. Specifically: - Less than 40 minutes: Excellent; - Not less than 40 minutes but less than 62 minutes: Good; - No less than 62 minutes: Not expected.

[0058] Foaming performance The foaming performance was tested as follows: - Dilute the cleaning agent with water to a free acid value of 10, and determine the free acid value according to the aforementioned method; - Place 300 ml of the dilution solution into a graduated stirrer (model: MX1600XTX, manufactured by Intertek) with a capacity of 2000 ml and stir vigorously for 20 seconds at 60% of the rated load, then let stand for 3 minutes. - Record the final total volume, including both foam volume and solution volume.

[0059] The lower the final total volume, the better the foaming performance of the cleaning agent. Specifically: - Less than 570ml: Expected; - Not less than 570ml: Not expected.

[0060] Examples 1 to 11 Samples were prepared by mixing all the components listed in Table 1. The preparation process and testing methods for these samples were identical. The test results are shown in Table 1.

[0061] Table 1:

[0062] Although some preferred embodiments have been described, modifications and variations can be made based on the above teachings. Therefore, it should be understood that the invention can be practiced in ways different from those specifically described without departing from the scope of the appended claims.

Claims

1. A cleaning agent for two-piece aluminum cans, wherein the cleaning agent comprises: (a) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene ethers, (b) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene polyoxypropylene ethers, wherein the polyoxyethylene polyoxypropylene ether portion has a total number of ethylene oxide (EO) units and propylene oxide (PO) units in the range of 10 to 17. (c) Sulfuric acid, and (d) Water.

2. The cleaning agent according to claim 1, wherein the cleaning agent comprises: (a) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene ethers, wherein - The fatty alcohol moiety has 12 to 24, preferably 12 to 18, carbon atoms, and / or - The polyoxyethylene ether portion has 7-12, preferably 8-10, number of ethylene oxide (EO) units. (b) One or more nonionic surfactants selected from fatty alcohol polyoxyethylene polyoxypropylene ethers, wherein - The fatty alcohol moiety has 10 to 18, preferably 10 to 16, carbon atoms, and / or - The fatty alcohol moiety is linear, and / or - The polyoxyethylene ether portion has 6-12, preferably 6-10, more preferably 7-9 ethylene oxide (EO) units, and / or - The polyoxypropylene ether portion has 3-10, preferably 3-7, more preferably 4-6 oxypropylene (PO) units, and / or (c) Sulfuric acid, and (d) Water.

3. The cleaning agent according to claim 1 or 2, wherein the nonionic surfactant (a) is included in the cleaning agent in an amount of 1.0% to 4.5% by weight, preferably 2.5% to 3.5% by weight, based on the total weight of the cleaning agent.

4. The cleaning agent according to any one of claims 1 to 3, wherein the nonionic surfactant (b) is included in the cleaning agent in an amount of 2.5% to 6.5% by weight, preferably 3.0% to 5.5% by weight, based on the total weight of the cleaning agent.

5. The cleaning agent according to any one of claims 1 to 4, wherein the total weight of the nonionic surfactant (a) and the nonionic surfactant (b) is 3.5% to 10.0% by weight, preferably 5.0% to 8.5% by weight, based on the total weight of the cleaning agent.

6. The cleaning agent according to any one of claims 1 to 5, wherein the weight ratio (a) / (b) of the nonionic surfactant (a) to the nonionic surfactant (b) is in the range of 0.30 to 1.1, preferably 0.55 to 1.

0.

7. The cleaning agent according to any one of claims 1 to 6, wherein sulfuric acid is included in the cleaning agent in an amount of 25% to 45% by weight, preferably 30% to 40% by weight, based on the total weight of the cleaning agent.

8. The cleaning agent according to any one of claims 1 to 7, wherein the cleaning agent further comprises ferric sulfate (III), preferably in an amount of 0.1% to 2.5% by weight, more preferably 0.5% to 2.0% by weight, based on the total weight of the cleaning agent.

9. The cleaning agent according to any one of claims 1 to 8, wherein the ratio of the number of EO units to the number of PO units in component (b) is in the range of 1 to 2, preferably 1.1 to 1.

8.

10. The cleaning agent according to any one of claims 1 to 9, wherein the total number of ethylene oxide (EO) units and propylene oxide (PO) units in the nonionic surfactant (b) is in the range of 10 to 15, preferably 12 to 15.

11. The cleaning agent according to any one of claims 1 to 10, wherein the fatty alcohol polyoxyethylene ether is a linear fatty alcohol polyoxyethylene ether.

12. The cleaning agent according to any one of claims 1 to 11, wherein - The cleaning agent does not contain anionic surfactants, and / or - The cleaning agent does not contain cationic surfactants, and / or - The cleaning agent does not contain amphoteric surfactants, and / or, - The cleaning agent does not contain amphoteric surfactants, and / or, - The cleaning agent does not contain nonionic surfactants other than surfactants (a) and (b), and / or - The cleaning agent does not contain organic acids, and / or, - The cleaning agent does not contain non-surfactant polymers, and / or, - The cleaning agent does not contain alkaline substances, which include organic and inorganic bases, and / or - The cleaning agent does not contain organic solvents.

13. A diluted solution of the cleaning agent according to any one of claims 1 to 12, wherein the diluted solution is obtained by diluting the cleaning agent according to any one of claims 1 to 12 with water, and the diluted solution has a free acid value of 7 to 20, preferably 8 to 15.

14. A cleaning method for cleaning two-piece aluminum cans, comprising the step of spraying a diluted solution according to claim 13 onto the two-piece aluminum can, wherein the cleaning is performed at a temperature of 45 to 55°C, particularly about 50°C.

15. The cleaning method according to claim 14, comprising the step of diluting the cleaning agent according to any one of claims 1 to 12 with water to obtain the diluted solution.

16. Use of the cleaning agent according to any one of claims 1 to 12 or the diluted solution according to claim 13 for cleaning two-piece aluminum cans.

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