Composition, surface-treated aluminum material, and method for manufacturing surface-treated aluminum material

Abstract

To provide a composition which can perform black discoloration prevention treatment and wettability improvement treatment of an aluminum material at the same time, and suppresses foaming.SOLUTION: A composition contains an amino resin (A), and a nonionic surface active agent (C).SELECTED DRAWING: None

Description

[Technical Field] 【0001】 The present invention relates to a composition, a surface-treated aluminum material, and a method for manufacturing a surface-treated aluminum material. [Background technology] 【0002】 In daily life, various products and components made from aluminum are widely used. A prime example is the aluminum can. Aluminum cans are widely used as containers for items that need to be preserved, including beverages and food. 【0003】 Aluminum cans are typically manufactured by creating a bottomed cylindrical molded body with an opening using an aluminum plate, and the final state before the contents are filled is when the sides are printed or painted. In particular, aluminum cans for food and beverages are usually sterilized at high temperatures after being filled and sealed. During this high-temperature sterilization process, the bottom and other surfaces that are not printed or painted will blacken if left untreated. Therefore, to prevent this blackening, the bottom and other surfaces of the aluminum can are usually treated by spraying them with a blackening prevention composition (see Patent Document 1). [Prior art documents] [Patent Documents] 【0004】 [Patent Document 1] Japanese Patent Application Publication No. 9-136062 [Overview of the project] [Problems that the invention aims to solve] 【0005】 On the other hand, improving the wettability of the bottom surface of an aluminum can may facilitate surface treatment with the aforementioned composition. Therefore, it is conceivable to spray a surfactant onto the bottom surface of an aluminum can for surface treatment. In other words, by treating the bottom surface of an aluminum molded body with a surfactant and then subsequently treating it with the aforementioned composition for preventing blackening, it may be possible to improve the blackening prevention effect. 【0006】 However, when various chemicals are sprayed, cleaning of the manufacturing equipment becomes necessary to prevent unintended contamination of aluminum materials such as aluminum molded products by residual chemicals, which reduces manufacturing efficiency. Therefore, there is a desire to reduce the number of times various chemicals are sprayed, and when performing both blackening prevention treatment and wettability improvement treatment on aluminum materials, it would be useful if these treatments could be performed simultaneously with a single spray of the chemical. In contrast, the surface treatment agent disclosed in Patent Document 1 is not suited to such an objective. 【0007】 Furthermore, by suppressing foaming of the composition, when an aluminum can is surface-treated with the composition, a layer of the composition can be formed on the surface of the aluminum can with high uniformity, and as a result, a high surface treatment effect can be expected. In contrast, the surface treatment agent disclosed in Patent Document 1 is not suited to such an objective. 【0008】 The present invention aims to provide a composition that can simultaneously perform a blackening prevention treatment and a wettability improvement treatment on aluminum materials, and further suppresses foaming. [Means for solving the problem] 【0009】 To solve the above problems, the present invention adopts the following configuration. [1] A composition containing an amino resin (A) and a nonionic surfactant (C). [2]. The composition contains surfactant (C1) as the nonionic surfactant (C), and in the ester of a hydroxyl group-containing fatty acid and glycerin, one or more of the said hydroxyl groups of surfactant (C1) are replaced by a group represented by the following general formula (i): -O(R 11 O) n H (i) (In the formula, n is an integer of 2 or more; R 11 is an alkylene group, and n R 11 may be the same as or different from each other.) and has a structure substituted by a group represented by the formula (however, when two or more of the said hydroxyl groups are substituted by a group represented by the general formula (i), these two or more groups represented by the general formula (i) may be the same as or different from each other), the composition according to [1]. [3]. The composition contains surfactant (C2) as the nonionic surfactant (C), and surfactant (C2) has either one or both of an oxyethylene group and an oxypropylene group, the composition according to [1] or [2]. 【0010】 [4]. The composition further contains an acid catalyst (B), the composition according to any one of [1] to [3]. [5]. The amino resin (A) is a melamine resin, the composition according to any one of [1] to [4]. [6]. The molecular weight of surfactant (C1) is 800 or more, the composition according to [2] or [3]. [7]. Surfactant (C2) is polyethylene glycol monoalkyl ether, the composition according to [3]. [8]. The acid catalyst (B) is one or more selected from the group consisting of phosphoric acid, phosphoric acid derivatives, and sulfonic acid, the composition according to [4]. 【0011】 [9]. A surface-treated aluminum material comprising an aluminum material and a treatment layer provided on the surface of the aluminum material, wherein the treatment layer is a reaction product of the composition according to any one of [1] to [8], the surface-treated aluminum material.

[10] A method for manufacturing a surface-treated aluminum material comprising an aluminum material and a treatment layer provided on the surface of the aluminum material, the method comprising: (I) forming a layer of the composition described in any one of [1] to [8] on the surface of the aluminum material using the composition described in any one of [1] to [8]; and (II) forming the treatment layer, which is a reactant of the composition, on the surface of the aluminum material by heat-treating the layer of the composition.

[11] The method for producing a surface-treated aluminum material according to

[10] , wherein the aluminum material is an aluminum can, and in step (I), a layer of the composition is formed by spraying the composition onto one or more of the bottom, side and inner surfaces of the aluminum can using a spray washer, and the composition that did not form a layer is recovered. [Effects of the Invention] 【0012】 According to the present invention, a composition is provided that can simultaneously perform a blackening prevention treatment and a wettability improvement treatment on an aluminum material, and further suppresses foaming. [Brief explanation of the drawing] 【0013】 [Figure 1] This is a schematic enlarged cross-sectional view showing an example of a surface-treated aluminum material according to one embodiment of the present invention. [Figure 2] This is a schematic enlarged cross-sectional view showing another example of a surface-treated aluminum material according to one embodiment of the present invention. [Figure 3] This is a schematic enlarged cross-sectional view showing an example of a method for manufacturing a surface-treated aluminum material according to one embodiment of the present invention. [Modes for carrying out the invention] 【0014】 <<Composition>> A composition according to one embodiment of the present invention contains an amino resin (A) and a nonionic surfactant (C). By surface-treating an aluminum material with the composition of this embodiment, not only can blackening of the aluminum material be prevented, but the wettability of the aluminum material can also be improved. More specifically, by surface-treating an aluminum material with the composition, the wettability of the aluminum material is improved, the surface of the aluminum material is more uniformly coated by the composition itself, and blackening of the aluminum material is prevented by the composition. In other words, the composition makes it possible to perform blackening prevention treatment and wettability improvement treatment on an aluminum material simultaneously, eliminating the need to perform the blackening prevention treatment and wettability improvement treatment separately. Furthermore, since foaming is suppressed in the composition, when a layer of the composition is formed on the surface of an aluminum material using the composition for surface treatment, the layer of the composition can be formed with high uniformity. As a result, the treatment layer, which is the reactant of the composition, can be formed on the surface of the aluminum material with high uniformity, and the effect of the blackening prevention treatment is enhanced. 【0015】 In this specification, "blackening of aluminum material" means "blackening of aluminum material when heated," unless otherwise specified. In this case, heating refers to heating at a high temperature, such as that which is sufficient for high-temperature sterilization, and typically refers to heating at a temperature of 65°C or higher. 【0016】 <Amino resin (A)> The amino resin (A) is a self-condensing component, and when an aluminum material is surface-treated with the composition, it forms reaction products such as its self-condensates on the surface of the aluminum material, thereby preventing the aluminum material from turning black when heated. The amino resin (A) can be considered as a type of crosslinking agent. 【0017】 The amino resin (A) is not particularly limited as long as it is a resin produced by the reaction of a compound having an amino group with an aldehyde. Examples of amino resins (A) include melamine resin, aniline formaldehyde resin, guanamine resin, urea resin, glycoluryl resin, and the like. 【0018】 Examples of commercially available amino resins (A) include "Watersol® S-695" manufactured by DIC Corporation and "Uban® N705" manufactured by Mitsui Chemicals, Inc. 【0019】 The molecular weight of the amino resin (A) is preferably 1000 or more, and more preferably 1500 or more. A molecular weight of amino resin (A) above the aforementioned lower limit enhances the effect of preventing blackening of the aluminum material. The upper limit of the molecular weight of amino resin (A) is not particularly limited. For example, in terms of making amino resin (A) more readily available, the molecular weight of amino resin (A) is preferably 4000 or less, but may also be 3000 or less. The molecular weight of the amino resin (A) may be, for example, 1000-4000, 1500-4000, or 1500-3000. 【0020】 The molecular weight of amino resin (A) can be measured by known methods. 【0021】 The amino resin (A) contained in the above composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0022】 In terms of providing a higher effect in preventing blackening of aluminum materials, it is preferable that the amino resin (A) is a melamine resin. 【0023】 <Nonionic surfactant (C)> The nonionic surfactant (C) is not particularly limited as long as it is a nonionic (non-ionic) surfactant. Examples of nonionic surfactants (C) include ether-ester type nonionic surfactants that have both ether and ester bonds in one molecule; and ether type nonionic surfactants that do not have ester bonds in one molecule but have ether bonds. 【0024】 The composition preferably contains either or both of the ether-ester type nonionic surfactant and the ether-type nonionic surfactant as the nonionic surfactant (C), and more preferably contains both the ether-ester type nonionic surfactant and the ether-type nonionic surfactant. 【0025】 The HLB value of the nonionic surfactant (C) is preferably 6 to 16, and more preferably 8 to 14. By using a nonionic surfactant (C) with an HLB value within this range, the effects of the present invention can be more significantly obtained. In this specification, "HLB value" refers to the value calculated using the Griffin method unless otherwise specified. 【0026】 Preferred nonionic surfactants (C) include, for example, surfactants (C1) and surfactant (C2) described later. In other words, the composition preferably contains either surfactant (C1) or surfactant (C2) or both as the nonionic surfactant (C), and more preferably contains both surfactant (C1) and surfactant (C2). Next, we will explain these surfactants (C1) and (C2) in order. 【0027】 [Surfactants (C1)] The surfactant (C1) is an ester (sometimes referred to as "hydroxyacylglycerol" herein) of a hydroxyl group-containing fatty acid and glycerin in which one or more hydroxyl groups are of the following general formula (i): -O(R 11 O) n H (i) (wherein n is an integer greater than or equal to 2; R 11 is an alkylene group, and n R 11 They may be the same or different from each other. A nonionic surfactant (C) having a structure substituted with groups represented by the above general formula (i) (however, if two or more of the hydroxyl groups are substituted with groups represented by the above general formula (i), these two or more groups represented by the above general formula (i) may be the same or different from each other). Surfactant (C1) is an ether-ester type nonionic surfactant. 【0028】 The surfactant (C1) alone can improve the wettability of the aluminum material, and can also form reaction products such as condensates with the amino resin (A), and these reaction products can also improve the wettability of the aluminum material. 【0029】 The number of acyl skeletons in the hydroxyacylglycerol in surfactant (C1) is 1 to 3. That is, surfactant (C1) is a monoacylglycerol derivative, a diacylglycerol derivative, or a triacylglycerol derivative. Here, "acyl skeleton" is a concept that encompasses an acyl group and a substituted acyl group having one or both of the hydroxyl group and the group represented by the general formula (i) as substituents. Surfactant (C1) has one, two, or three of the substituted acyl groups. When the number of acyl skeletons in the hydroxyacylglycerol is two or three, these multiple acyl skeletons may be identical or different from each other. That is, these multiple acyl skeletons may all be identical, all be different, or only some may be identical. A surfactant (C1) in which all of the multiple acyl skeletons are identical is more readily available or can be manufactured. 【0030】 The acyl group and the acyl group before being substituted with the substituent of the substituted acyl group (which may be referred to as the "pre-substituted acyl group" in this specification) preferably have a chain length that can be regarded as being derived from a long-chain fatty acid, and the number of carbon atoms of the acyl group and the pre-substituted acyl group is preferably 12 or more. By using the surfactant (C1) in which the number of carbon atoms of the acyl group and the pre-substituted acyl group is within such a range, the wettability of the aluminum material becomes higher. The number of carbon atoms of the acyl group and the pre-substituted acyl group is the number of carbon atoms of the group represented by the general formula (i) or the acyl group before being substituted with a hydroxyl group, and does not include the number of carbon atoms of the group represented by the general formula (i). The upper limit value of the number of carbon atoms of the acyl group and the pre-substituted acyl group is not particularly limited. For example, in terms of easier availability or production of the surfactant (C1), the number of carbon atoms of the acyl group and the pre-substituted acyl group is preferably 24 or less. 【0031】 The hydrocarbon group (the hydrocarbon group bonded to the carbon atom in the carbonyl group) constituting the acyl group and the pre-substituted acyl group is preferably an aliphatic hydrocarbon group (a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group), and more preferably an alkyl group (a saturated aliphatic hydrocarbon group) or an alkenyl group. When the surfactant (C1) has such a hydrocarbon group constituting the acyl group and the pre-substituted acyl group, it can be more easily obtained or produced, and by using such a surfactant (C1), the wettability of the aluminum material becomes higher. 【0032】 In the general formula (i), n is the number of repetitions of the group represented by the general formula "-R 11 -O-" (an alkyleneoxy group), is an integer of 2 or more, is preferably 15 to 60, and more preferably 30 to 40. When n is within such a range, the effect of using the surfactant (C1), that is, the effect of improving the wettability of the aluminum material, becomes higher. 【0033】 In the general formula (i), the R 11This is an alkylene group, preferably a linear alkylene group, and more preferably an alkylene group having 2 or 3 carbon atoms (ethylene group or propylene group). 【0034】 n R in general formula (i) 11 These can be identical or different from one another. That is, n R 11 These may all be identical, all be different, or only partially identical. n R 11 Surfactants (C1) in which all are identical can be more readily obtained or manufactured. 【0035】 If the number of substitutions of the hydroxyl groups in the hydroxyacyl groups of the hydroxyacyl glycerol by the group represented by the general formula (i), in other words, the number of groups represented by the general formula (i) in the surfactant (C1), is 2 or more, then these two or more groups represented by the general formula (i) may be identical or different. That is, the two or more groups represented by the general formula (i) may all be identical, all be different, or only some may be identical. Surfactants (C1) in which the two or more groups represented by the general formula (i) are all identical can be more readily obtained or manufactured. 【0036】 It is preferable that all hydroxyacyl groups in the hydroxyacylglycerol, regardless of their number, have groups represented by the general formula (i). Using such a surfactant (C1) further enhances the wettability of the aluminum material. 【0037】 The number of substitutions of the hydroxyl group in the hydroxyacyl group in the hydroxyacylglycerol by the group represented by the general formula (i), in other words, the number of groups represented by the general formula (i) in the surfactant (C1), is preferably 1 to 3, more preferably 2 or 3, and even more preferably 3. 【0038】 The substitution position of the hydroxyl group in the hydroxyacyl group in the hydroxyacylglycerol by the group represented by general formula (i), in other words, the bonding position of the group represented by general formula (i) in the hydroxyacyl group, is not particularly limited and may be a terminal carbon atom or a non-terminal carbon atom in the hydroxyacyl group. 【0039】 When the number of substituted acyl groups in the hydroxyacylglycerol is two or three, these substituted acyl groups may be identical or different from each other. That is, these substituted acyl groups may all be identical, all be different, or only some may be identical. A surfactant (C1) in which all of the substituted acyl groups are identical is more readily available or can be manufactured. 【0040】 In surfactant (C1), it is preferable that all hydroxyl groups in the hydroxyacyl group are replaced with the group represented by the general formula (i). That is, it is preferable that surfactant (C1) does not have hydroxyl groups in the acyl skeleton. 【0041】 The molecular weight of the surfactant (C1) is preferably 800 or more, more preferably 900 to 4000, and even more preferably 1500 to 2500. Having the molecular weight of the surfactant (C1) within this range improves the wettability of the aluminum material. 【0042】 A preferred surfactant (C1) is, for example, the following general formula (c)-11: 【0043】 [ka] (In the formula, n is an integer greater than or equal to 2.) Examples include compounds represented by (sometimes referred to as "surfactants (C11)" in this specification). 【0044】 The surfactant (C1) contained in the above composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0045】 If the composition contains a surfactant (C1), the amount of surfactant (C1) in the composition is preferably 0.1 to 10 times the amount of amino resin (A) in molars (the molar ratio of [moles of surfactant (C1) in the composition] / [moles of amino resin (A) in the composition] is 0.1 to 10). For example, it may be 0.1 to 7 times the amount of molars and 0.1 to 4 times the amount of molars, or 1.5 to 10 times the amount of molars and 2.5 to 10 times the amount of molars, or 1.5 to 7 times the amount of molars and 2.5 to 4 times the amount of molars. When the amount of surfactant (C1) is above the lower limit, the wettability of the aluminum material is increased. When the amount of surfactant (C1) is below the upper limit, excessive use of surfactant (C1) is suppressed. 【0046】 [Surfactant (C2)] The surfactant (C2) is a nonionic surfactant (C) having either an oxyethylene group or an oxypropylene group or both, and is an ether-type nonionic surfactant that does not correspond to surfactant (C1). 【0047】 The surfactant (C2) alone can improve the wettability of the aluminum material and suppress foaming of the composition. Furthermore, it can form a reaction product such as a condensate with the amino resin (A), and this reaction product can also improve the wettability of the aluminum material and suppress foaming of the composition. In other words, the surfactant (C2) is a component that improves the wettability of the aluminum material and suppresses foaming of the composition. 【0048】 A composition containing surfactant (C1) may not suppress foaming on its own, but a composition containing both surfactant (C1) and surfactant (C2) (the aforementioned composition) can suppress foaming. 【0049】 More specifically, as a surfactant (C2), for example, the following general formula (c)-21: R 21 O(CH2CH2O) l H (c)-21 (In the formula, R 21 (where l is an alkyl group; l is an integer greater than or equal to 2.) A polyethylene glycol monoalkyl ether represented by (sometimes referred to as "surfactant (C21)" in this specification) and the following general formula (c)-22: R 22 O(CH2CH(CH3)O) m H (c)-22 (In the formula, R 22 (where m is an alkyl group; m is an integer greater than or equal to 2.) A polypropylene glycol monoalkyl ether represented by (sometimes referred to as "surfactant (C22)" in this specification) and the following general formula (c)-23: R 23 O(CH2CH2O) p (CH2CH(CH3)O) q H (c)-23 (In the formula, R 23 (where p is an alkyl group; p and q are each independent integers greater than or equal to 2.) Examples include polyalkylene glycol monoalkyl ethers represented by (which may be referred to as "surfactants (C23)" in this specification). 【0050】 The R in the general formula (c)-21 21 , the R in the general formula (c)-22 22 , and the R in the general formula (c)-23 23 These are each an alkyl group independently. R 21 , R 22 and R23 The alkyl group in the above may be linear, branched, or cyclic, but it is preferably linear or branched, and more preferably branched. By using a surfactant (C21), (C22), or (C23) in which the alkyl group is linear or branched, and especially branched, the foaming of the composition is further suppressed. In particular, by using a surfactant (C21), (C22), or (C23) in which the alkyl group has a branched carbon chain structure at its terminal end, the foaming of the composition is significantly suppressed. 【0051】 In terms of the effect of suppressing foaming of the above composition, R 21 , R 22 and R 23 The alkyl group in the above preferably has a plurality of branched structures. 【0052】 R 21 , R 22 and R 23 The number of carbon atoms in the alkyl group is preferably 7 to 20. By using a surfactant (C21), (C22), or (C23) with a carbon number within this range, the effect of suppressing foaming of the composition is further enhanced. 【0053】 In the general formula (c)-21, the value of l is the number of repeating ethyleneoxy groups. In the general formula (c)-22, m represents the number of repeating propyleneoxy groups. In the general formula (c)-23, p is the number of repeating ethyleneoxy groups, and q is the number of repeating propyleneoxy groups. l, m, p, and q are each independent integers of 2 or more, preferably between 2 and 14, and more preferably between 4 and 10. When l, m, p, and q are within this range, the effects of using the surfactants (C21), (C22), and (C23), namely the effect of improving the wettability of the aluminum material and the effect of suppressing foaming of the composition, are further enhanced. 【0054】 The molecular weight of the surfactant (C2) is preferably 350 to 450, and more preferably 380 to 420. Having the molecular weight of the surfactant (C2) within this range improves the wettability of the aluminum material. Furthermore, having the molecular weight of the surfactant (C2) below the upper limit further enhances the effect of suppressing foaming in the composition. 【0055】 The surfactant (C2) contained in the above composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0056】 In terms of improving the wettability of the aluminum material and significantly suppressing foaming of the composition, the surfactant (C2) is preferably polyethylene glycol monoalkyl ether (surfactant (C21)), and more preferably polyethylene glycol monoalkyl ether (surfactant (C21)) in which the alkyl group constituting the alkyl ether has a branched carbon chain structure at its terminal end. 【0057】 If the composition contains a surfactant (C2), the amount of surfactant (C1) in the composition is preferably 0.05 to 5 times the amount of amino resin (A) in molars (the molar ratio of [moles of surfactant (C2) in the composition] / [moles of amino resin (A) in the composition] is 0.05 to 5). For example, it may be 0.05 to 3 times the amount of molars, or 0.05 to 1.5 times the amount of molars, or 0.2 to 5 times the amount of molars, or 2 to 5 times the amount of molars, or 0.2 to 3 times the amount of molars. When the amount of surfactant (C2) is above the lower limit, the wettability of the aluminum material is increased, and the effect of suppressing foaming of the composition is increased. When the amount of surfactant (C2) is below the upper limit, excessive use of surfactant (C2) is suppressed. 【0058】 If the composition contains surfactants (C1) and (C2), the content of surfactant (C2) in the composition is preferably 0.05 to 2 times the molar amount of surfactant (C1) (the molar ratio of [moles of surfactant (C2) in the composition] / [moles of surfactant (C1) in the composition] is 0.05 to 2), for example, it may be 0.05 to 0.8 times, 0.05 to 0.6 times, or 0.05 to 0.4 times. Having the surfactant (C2) content in this range increases the wettability of the aluminum material and enhances the foaming suppression effect of the composition. 【0059】 [Surfactant (C3)] Examples of nonionic surfactants (C) include surfactants (C1) and surfactants (C2), as well as other surfactants (C3) that do not fall under either category (in this specification, these may be simply referred to as "surfactants (C3)"). Examples of surfactants (C3) include ethers of sorbitan and polyethylene glycol, which are esters formed by the reaction of a hydroxyl group in an ether having a hydroxyl group derived from polyethylene glycol with a carboxyl group in a fatty acid (sometimes referred to as "sorbitan-based nonionic surfactants" in this specification); esters of fatty acids and polyethylene glycol that do not fall under the category of sorbitan-based nonionic surfactants (sometimes referred to as "polyethylene glycol-based nonionic surfactants" in this specification); and esters of fatty acids and polyethylene glycol derivatives (sometimes referred to as "polyethylene glycol derivative-based nonionic surfactants" in this specification). These are all ether ester-type nonionic surfactants. Examples of the sorbitan-based nonionic surfactant include compounds represented by the following general formula (c)-31. Examples of the polyethylene glycol-based nonionic surfactant include compounds represented by the following general formula (c)-32. Examples of the polyethylene glycol derivative-based nonionic surfactant include compounds represented by the following general formula (c)-33. 【0060】 [ka] (In the formula, m, p, and q are each independent integers greater than or equal to 2.) 【0061】 In the composition, the content of the nonionic surfactant (C) is preferably 0.1 to 10 times the molar amount of the amino resin (A) (the molar ratio of [content of nonionic surfactant (C) in the composition (moles)] / [content of amino resin (A) in the composition (moles)] is 0.1 to 10), for example, it may be 0.1 to 7 times the molar amount, or 0.1 to 4 times the molar amount, or 2 to 10 times the molar amount, or 5 to 10 times the molar amount, or 2 to 7 times the molar amount. When the content of the nonionic surfactant (C) is above the lower limit, the effect of preventing blackening of the aluminum material, the effect of improving the wettability of the aluminum material, and the effect of suppressing foaming of the composition are enhanced. When the content of the nonionic surfactant (C) is below the upper limit, the excessive use of the nonionic surfactant (C) is suppressed. In this specification, the content of nonionic surfactant (C) in the composition means the total content of surfactant (C1) and surfactant (C2) in the composition if the composition contains only one or both of surfactant (C1) and surfactant (C2) as nonionic surfactant (C). 【0062】 <Other ingredients (E)> The composition may also contain, in addition to the amino resin (A) and the nonionic surfactant (C), other components (which may be referred to as "other components (E)" in this specification) that do not fall under either of these categories (amino resin (A) or nonionic surfactant (C)). 【0063】 The other component (E) contained in the composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0064】 Other components (E) contained in the composition include, for example, an acid catalyst (B) described later; other surfactants (Y) that do not fall under the category of nonionic surfactants (C) (sometimes referred to as "other surfactants (Y)" in this specification); crosslinking agents that do not fall under the category of amino resins (A) (sometimes referred to as "crosslinking agents (X)" in this specification); additives (Z); solvents, etc. 【0065】 Among other preferred components (E), an acid catalyst (B) is mentioned. That is, it is preferable that the composition further contains an acid catalyst (B). The inclusion of an acid catalyst (B) in addition to the amino resin (A) and nonionic surfactant (C) in the composition further enhances the effect of the composition in preventing blackening of aluminum materials. 【0066】 [Acid catalyst (B)] Examples of the acid catalyst (B) include an acid catalyst that promotes the self-condensation reaction of the amino resin (A); an acid catalyst that promotes the condensation reaction between the amino resin (A) and the nonionic surfactant (C) (for example, the condensation reaction between the amino resin (A) and the surfactant (C1), and the condensation reaction between the amino resin (A) and the surfactant (C2)). It may also be an acid catalyst that promotes both the self-condensation reaction of the amino resin (A) and the condensation reaction between the amino resin (A) and the nonionic surfactant (C). 【0067】 Examples of acid catalysts (B) include phosphoric acid (H3PO4), phosphoric acid derivatives, and sulfonic acid. 【0068】 In this specification, when a particular compound is assumed to have a structure in which one or more hydrogen atoms are replaced by groups (substituents) other than hydrogen atoms, a compound having such a substituted structure will be referred to as a "derivative" of the particular compound described above. In this specification, the term "group" includes not only atomic groups having a structure in which multiple atoms are bonded together, but also a single atom. 【0069】 The acid catalyst (B), which is a phosphoric acid derivative, is not particularly limited as long as it is a compound having a structure in which one or more hydrogen atoms in the phosphoric acid are replaced by groups (substituents) other than hydrogen atoms. When a single molecule of phosphate derivative has two or more of the substituents, these two or more substituents may all be the same, all be different, or only partially the same. 【0070】 Preferred phosphoric acid derivatives include, for example, phosphoric acid esters such as alkyl phosphates (monoalkyl phosphates, dialkyl phosphates, trialkyl phosphates), and dialkyl phosphates (monoalkyl phosphates, dialkyl phosphates, triesters). 【0071】 The sulfonic acid, which is the acid catalyst (B), is not particularly limited as long as it is a compound having one or more sulfo groups (-SO3H) in one molecule. 【0072】 Preferred sulfonic acids include, for example, aryl sulfonic acids and aryl sulfonic acid derivatives such as benzenesulfonic acid derivatives and naphthalenesulfonic acid derivatives. The benzenesulfonic acid derivative is not particularly limited as long as it is a compound having a structure in which one or more hydrogen atoms in benzenesulfonic acid are replaced by groups (substituents) other than hydrogen atoms. The naphthalene sulfonic acid derivative is not particularly limited as long as it is a compound having a structure in which one or more hydrogen atoms in naphthalene sulfonic acid are replaced by groups (substituents) other than hydrogen atoms. When a single molecule of a benzenesulfonic acid derivative or naphthalenesulfonic acid derivative has two or more of the substituents, these two or more substituents may all be the same, all be different, or only partially the same. 【0073】 Examples of the benzenesulfonic acid derivatives include dodecylbenzenesulfonic acid and p-toluenesulfonic acid. Examples of the naphthalene sulfonic acid derivatives include dinonylnaphthalene disulfonic acid and dinonylnaphthalene monosulfonic acid. 【0074】 The acid catalyst (B) contained in the above composition may be only one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0075】 For a more effective prevention of blackening of aluminum materials, the acid catalyst (B) is preferably one or more selected from the group consisting of phosphoric acid, phosphoric acid derivatives, and sulfonic acid. 【0076】 If the composition contains an acid catalyst (B), the content of the acid catalyst (B) in the composition is preferably 0.02 to 4 times the molar amount of the amino resin (A) (the molar ratio of [content of acid catalyst (B) in the composition (moles)] / [content of amino resin (A) in the composition (moles)] is 0.02 to 4). For example, it may be 0.02 to 2 times the molar amount and 0.02 to 1 time the molar amount, or 0.15 to 4 times the molar amount and 0.5 to 4 times the molar amount, or 0.15 to 2 times the molar amount and 0.5 to 1 time the molar amount. When the content of the acid catalyst (B) is above the lower limit, the effect of preventing blackening of the aluminum material is further enhanced. When the content of the acid catalyst (B) is below the upper limit, excessive use of the acid catalyst (B) is suppressed. 【0077】 [Other surfactants (Y)] The other surfactant (Y) is not particularly limited as long as it is a surfactant that does not fall under the category of a nonionic surfactant (C). The other surfactant (Y) may be, for example, a cationic surfactant, an anionic surfactant, or an amphoteric surfactant. 【0078】 The other surfactant (Y) contained in the composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0079】 In the above composition, the content of other surfactants (Y) is preferably 0.1 times the molar amount of the amino resin (A) or less (the molar ratio of [content of other surfactants (Y) in the composition (moles)] / [content of amino resin (A) in the composition (moles)] is 0.1 or less), more preferably 0.05 times the molar amount or less, even more preferably 0.03 times the molar amount or less, and particularly preferably 0 times the molar amount, that is, the composition does not contain other surfactants (Y). By keeping the content of other surfactants (Y) below the above upper limit, the effect of preventing blackening of the aluminum material and the effect of improving the wettability of the aluminum material are further enhanced. 【0080】 [Crosslinking agent (X)] The crosslinking agent (X) is not particularly limited as long as it has two or more groups that can react with other compounds and does not fall under the category of amino resin (A). The crosslinking agent (X) may be, for example, a monomer, an oligomer, or a polymer. Examples of crosslinking agents (X) include polyisocyanates. 【0081】 The crosslinking agent (X) contained in the composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0082】 In the above composition, the content of the crosslinking agent (X) is preferably 0.1 times the molar amount of the amino resin (A) or less (the molar ratio of [content of crosslinking agent (X) in the composition (moles)] / [content of amino resin (A) in the composition (moles)] is 0.1 or less), more preferably 0.05 times the molar amount or less, even more preferably 0.03 times the molar amount or less, and particularly preferably 0 times the molar amount, that is, the composition does not contain the crosslinking agent (X). By keeping the content of the crosslinking agent (X) below the above upper limit, the effect of preventing blackening of the aluminum material is further enhanced. 【0083】 [Additive (Z)] Examples of the additive (Z) include general-purpose additives known in the field, such as coupling agents, adhesion promoters, defoaming agents, and antioxidants. 【0084】 The additive (Z) contained in the composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0085】 The content of additive (Z) in the above composition can be appropriately adjusted depending on the type of additive (Z), and is not particularly limited. 【0086】 [solvent] The composition containing the aforementioned solvent is easy to handle. In this specification, unless otherwise specified, "solvent" is a concept that encompasses both a component that is liquid at room temperature for dissolving a solute and a component that is liquid at room temperature for dispersing a dispersed phase. Furthermore, "room temperature" means a temperature that is not specifically cooled or heated, i.e., a normal temperature, such as 15-25°C. 【0087】 Examples of the solvent include water and organic solvents. Examples of the aforementioned organic solvents include alcohols such as methanol, ethanol, 1-propanol (n-propyl alcohol), 2-propanol (isopropyl alcohol), 1-butanol (n-butyl alcohol), 2-methyl-1-propanol (isobutyl alcohol), 2-butanol (sec-butyl alcohol), and 2-methyl-2-propanol (tert-butyl alcohol); esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran and diethyl ether; amides (compounds having an amide bond) such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; and hydrocarbons such as toluene and xylene. 【0088】 The solvent contained in the composition may be one type or two or more types, and if there are two or more types, their combination and ratio can be arbitrarily selected. 【0089】 The ratio of the total content (parts by mass) of components other than the solvent to the total mass of the composition ([total content (parts by mass) of components other than the solvent in the composition] / [total mass (parts by mass) of the composition] × 100) is not particularly limited, but is preferably 10 to 10,000 ppm, and more preferably 50 to 5,000 ppm. When the ratio is above the lower limit, the aluminum material can be surface-treated more efficiently. When the ratio is below the upper limit, the handling of the composition is improved. 【0090】 In the above composition, the ratio of the total content of amino resin (A), acid catalyst (B), and nonionic surfactant (C) to the total content of all components other than the solvent (([Content of amino resin (A) in the above composition (parts by mass)] + [Content of acid catalyst (B) in the above composition (parts by mass)] + [Content of nonionic surfactant (C) in the above composition (parts by mass)]) / [Total content of all components other than the solvent in the above composition (parts by mass)] × 100) is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, for example, it may be 97% by mass or more, or 99% by mass or more. The effect of preventing blackening of the aluminum material is further enhanced when the above ratio is equal to or greater than the above lower limit. On the other hand, the aforementioned ratio is 100% by mass or less. If the composition does not contain the acid catalyst (B), the "content of the acid catalyst (B) in the composition" is 0 parts by mass. 【0091】 <Method for producing the composition (the aforementioned composition)> The composition is obtained by blending an amino resin (A), a nonionic surfactant (C), and optionally another component (E). After blending each component, the resulting product may be used as is, or it may be further purified using a known purification procedure as needed. 【0092】 The method of mixing the ingredients is not particularly limited and can be appropriately selected from known methods such as mixing by rotating a stirring bar or impeller, mixing using a mixer, or mixing by applying ultrasonic waves. 【0093】 In the manufacturing method described above, the temperature at each step until the composition is obtained is not particularly limited as long as the individual components do not deteriorate, and may be, for example, 5 to 80°C. The temperature can be appropriately adjusted according to the type and amount of the components so that the resulting mixture has a viscosity that is easy to stir. 【0094】 In the manufacturing method described above, the total time for adding and stirring the ingredients (the sum of the adding time and the stirring time) is not particularly limited as long as each ingredient does not deteriorate, and may be, for example, 10 minutes to 12 hours. 【0095】 <<Surface-treated aluminum material>> A surface-treated aluminum material according to one embodiment of the present invention comprises an aluminum material and a treatment layer provided on the surface of the aluminum material, wherein the treatment layer is a reaction product of the composition according to the above-described embodiment of the present invention. In the region of the aluminum material where the treated layer (a treated layer formed from the composition) which is a reactant of the composition is provided, blackening during heating is prevented. In the region of the aluminum material where the layer of the composition is formed, its wettability is improved, so that the surface of the aluminum material is more uniformly coated by the composition. As a result, in the region of the aluminum material where the treated layer (a treated layer formed from the composition), which is a reactant of the composition, is provided, blackening during heating is prevented with high uniformity. Because the foaming of the composition is suppressed, a layer of the composition can be formed on the surface of the aluminum material with high uniformity. As a result, a treatment layer, which is a reaction product of the composition, can be formed on the surface of the aluminum material with high uniformity, and the effect of the blackening prevention treatment is enhanced. 【0096】 It is presumed that the reactants of the above composition include, for example, a self-condensed product of amino resin (A). It is presumed that the reactants of the composition include, for example, a condensate of an amino resin (A) and a nonionic surfactant (C). If the composition contains a surfactant (C1), it is presumed that the reactants of the composition include, for example, a condensate of an amino resin (A) and a surfactant (C1), and if the composition contains a surfactant (C2), it is presumed that the reactants of the composition include, for example, a condensate of an amino resin (A) and a surfactant (C2). 【0097】 The aluminum material in the surface-treated aluminum material is made of aluminum or has aluminum as its main component. In aluminum materials, the aluminum content relative to the total mass of the aluminum material is preferably 80% by mass or more, and may be, for example, 90% by mass or more, 95% by mass or more, 97% by mass or more, or 99% by mass or more. On the other hand, the aforementioned percentage is 100% by mass or less. 【0098】 The shape of the aluminum material is not particularly limited and can be arbitrarily selected according to the purpose. In terms of shape, aluminum materials can be classified into various types of molded aluminum products, such as aluminum cans, aluminum cups, aluminum lids, and aluminum caps. 【0099】 The thickness of the aluminum material is preferably 0.1 to 1 mm, more preferably 0.15 to 0.8 mm, and particularly preferably 0.2 to 0.7 mm. Aluminum material of this thickness is preferable because of its high versatility. 【0100】 The treatment layer in surface-treated aluminum material may consist of one layer (single layer) or of two or more layers. When the treatment layer consists of multiple layers, these layers may be identical or different from each other, and there are no particular limitations on the combination of these layers. 【0101】 In this specification, not only in the case of a processing layer, "multiple layers may be identical or different from one another" means "all layers may be identical, all layers may be different, or only some layers may be identical," and further, "multiple layers are different from one another" means "at least one of the constituent materials and thickness of each layer is different from the other." 【0102】 The thickness of the treated layer is preferably 0.1 to 100 nm, more preferably 0.2 to 80 nm, and particularly preferably 0.3 to 70 nm. A thickness of the treated layer greater than or equal to the lower limit enhances the effect of preventing blackening of the aluminum material. A thickness of the treated layer less than or equal to the upper limit avoids excessive thickness of the treated layer. Here, "thickness of the processing layer" refers to the total thickness of the processing layer. For example, the thickness of a processing layer consisting of multiple layers refers to the total thickness of all the layers that make up the processing layer. 【0103】 The amount of structure derived from amino resin (A) in the treated layer is 0.2 to 200 mg / m². 2 Preferably, the concentration is 0.4 to 160 mg / m². 2 It is more preferable that the concentration be 0.6-140 mg / m². 2 It is particularly preferable that the amount of structure derived from amino resin (A) is greater than or equal to the lower limit, thereby increasing the effect of preventing blackening of the aluminum material. It is also preferable that the amount of structure derived from amino resin (A) is less than or equal to the upper limit, thereby avoiding an excessive thickness of the treated layer. In this specification, "structure derived from amino resin (A) in the treated layer" means a structure in amino resin (A) in which the interatomic bonds are maintained without being broken even in the treated layer. For example, in the case of a self-condensate of amino resin (A), it means the structure of amino resin (A) excluding the hydrogen atoms (-H) and hydroxyl groups (-OH) that are removed by condensation. 【0104】 Figure 1 is a schematic enlarged cross-sectional view showing an example of a surface-treated aluminum material according to this embodiment. In addition, the diagrams used in the following explanation may be enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not be the same as in reality. 【0105】 The surface-treated aluminum material 1 shown herein comprises an aluminum material 11 and a treatment layer 12 provided on the surface of the aluminum material 11. The aluminum material 11 is either entirely plate-shaped or partially plate-shaped, and one side (surface) 11a of the plate-shaped portion is provided with a treatment layer 12. On the other hand, the other surface (front surface) 11b of the aluminum material 11 is the surface opposite to the first surface 11a. The one surface 11a and the other surface 11b of the aluminum material 11 may be flat, curved, or uneven, and their shapes are not particularly limited. 【0106】 The processing layer 12 is a reaction product of the composition. 【0107】 The aforementioned one surface 11a of the aluminum material 11 is the target of blackening prevention, and blackening is prevented by covering it with the treatment layer 12. On the other hand, the other surface 11b of the aluminum material 11 is not subject to blackening prevention and does not have a treatment layer. 【0108】 For example, if the aluminum material 11 is an aluminum can, one of the surfaces 11a of the aluminum material 11 may be the bottom surface, the side surface, or the inner surface (the surface on which the contents are filled). 【0109】 In this specification, unless otherwise specified, the bottom and sides of an aluminum can are both the outer surfaces of the aluminum can, or in other words, the outer bottom and outer sides of the aluminum can, respectively. The inner surface of an aluminum can refers to the entire surface on which the contents of the aluminum can are filled, and the inner bottom (in other words, the inner bottom) and the inner side (in other words, the inner side) of the aluminum can are both the inner surfaces of the aluminum can. 【0110】 Figure 2 is a schematic enlarged cross-sectional view showing another example of the surface-treated aluminum material of this embodiment. In Figures 2 and beyond, components identical to those shown in previously explained figures are denoted by the same reference numerals, and their detailed explanations are omitted. 【0111】 The surface-treated aluminum material 2 shown herein comprises an aluminum material 11, a first treatment layer 121 provided on one surface 11a of the aluminum material 11, and a second treatment layer 122 provided on the other surface 11b of the aluminum material 11. 【0112】 The first processing layer 121 and the second processing layer 122 are both reactants of the composition. In the surface-treated aluminum material 2, the first treatment layer 121 and the second treatment layer 122 may be the same as or different from each other. 【0113】 One surface 11a of the aluminum material 11 is subject to blackening prevention, and blackening is prevented by covering it with the first treatment layer 121. The other surface 11b of the aluminum material 11 is also subject to blackening prevention, and blackening is prevented by being covered with the second treatment layer 122. 【0114】 Surface-treated aluminum material 2 is the same as surface-treated aluminum material 1 shown in Figure 1, except that it has a second treatment layer 122 on the other surface 11b of the aluminum material 11. 【0115】 The surface-treated aluminum material of this embodiment is not limited to those shown in Figures 1 and 2. Within the scope of the present invention, some components of those shown in Figures 1 and 2 may be modified or deleted, or other components may be added to those described herein. For example, the aluminum material shown in Figures 1 and 2 is either entirely plate-shaped or partially plate-shaped, but the shape of the aluminum material is not limited to this. For example, it may be entirely or partially plate-shaped, or it may have both plate-shaped and non-plate-shaped forms. 【0116】 <<Manufacturing Method for Surface-Treated Aluminum Material>> A method for manufacturing a surface-treated aluminum material according to one embodiment of the present invention comprises the steps of (I) forming a layer of the composition on the surface of the aluminum material using the composition according to the present embodiment of the present invention described above, and (II) forming the treatment layer, which is a reactant of the composition, on the surface of the aluminum material by heat-treating the layer of the composition. 【0117】 Figure 3 is a schematic enlarged cross-sectional view showing an example of a method for manufacturing a surface-treated aluminum material according to this embodiment. Here, the manufacturing method will be explained using the case where the surface-treated aluminum material is the surface-treated aluminum material 1 shown in Figure 1 as an example. 【0118】 <Process (I)> In step (I) of the manufacturing method of this embodiment, a layer 120 of the composition is formed on one surface 11a of the aluminum material 11, as shown in Figure 3(a). 【0119】 In step (I), a layer 120 of the composition can be formed by adhering the composition to one surface 11a of the aluminum material 11. The method for attaching the composition to one surface 11a of the aluminum material 11 may be a known method, and can be appropriately selected depending on the type of composition or aluminum material 11. For example, the composition can be attached to one surface 11a of the aluminum material 11 by spraying the composition onto the aluminum material 11, coating the aluminum material 11 with the composition using various coaters, or immersing the aluminum material 11 in the composition. 【0120】 Among these methods, the preferred method for adhering the composition to the aluminum material 11 is to spray the composition onto the aluminum material 11. By spraying the composition onto the aluminum material 11, a dense and uniform layer 120 of the composition can be formed on the target area of ​​the aluminum material 11. In this case, the composition may be sprayed onto the aluminum material 11 using, for example, a spray washer. 【0121】 The method of spraying the composition onto the aluminum material 11 is more preferred when the aluminum material 11 is an aluminum can. By spraying the composition onto the aluminum can, a dense and uniform layer 120 of the composition can be formed on one or more of the bottom, sides, and inner surfaces of the aluminum can. In this case as well, the composition can be sprayed onto the aluminum can using a spray washer. That is, when the aluminum material 11 is an aluminum can, it is preferable in step (I) to spray the composition onto one or more of the bottom, sides, and inner surfaces of the aluminum can using a spray washer. 【0122】 When the composition is sprayed onto the aluminum material 11 using a spray washer, any portion of the composition that did not form a layer 120 can be recovered. The recovered composition may be sprayed onto the aluminum material 11 again. 【0123】 If the aluminum material 11 is an aluminum can, in step (I), it is preferable to use a spray washer to spray the composition onto one or more of the bottom, sides, and inner surfaces of the aluminum can, thereby forming a layer 120 of the composition and recovering the composition that did not form a layer. This not only allows for the formation of a dense and uniform layer 120 of the composition on the aluminum can, but also allows for the recovery of any excess composition. 【0124】 Since the composition can improve the wettability of the aluminum material, in step (I), one surface 11a of the aluminum material 11 can be more uniformly coated with the composition. Furthermore, since foaming is suppressed in the composition, in step (I), a layer of the composition can be formed with high uniformity on one surface 11a of the aluminum material 11. 【0125】 When the composition is sprayed onto two or more of the bottom, sides, and inner surfaces of the aluminum can, or when the composition is applied to two or more surfaces of the aluminum material 11, the composition may be applied to some or all of the two or more surfaces simultaneously, or the composition may be applied to all of the two or more surfaces in stages rather than simultaneously. For example, if the aluminum material 11 is an aluminum can, the composition may be applied (sprayed) to all of the bottom, sides, and inner surfaces of the aluminum can simultaneously, or to only two of the bottom, sides, and inner surfaces simultaneously, or to be applied to the bottom, sides, and inner surfaces in stages. When the composition is applied in stages to two or more surfaces of the aluminum material 11, the order in which the composition is applied to the surfaces is not particularly limited. 【0126】 In the composition used in step (I), the ratio of the total content (parts by mass) of components other than the solvent to the total mass of the composition is preferably 10 to 10,000 ppm. When the ratio is above the lower limit, the layer 120 of the composition can be formed more efficiently. When the ratio is below the upper limit, the handling of the composition is improved. More specifically, when the composition is attached to the aluminum material 11, the composition can be attached to the aluminum material 11 more easily, regardless of the method. For example, if the ratio of the prepared composition exceeds 10,000 ppm, it is preferable to add a solvent to dilute it and reduce the ratio of the composition to 10,000 ppm or less. Examples of solvents to be added at this time include the same solvent that may be contained in the composition. 【0127】 <Process (II)> In step (II) of the manufacturing method of this embodiment, the layer 120 of the composition is heat-treated to form a treatment layer 12, which is a reactant of the composition, on one surface 11a of the aluminum material 11, as shown in Figure 3(b). This yields the desired surface-treated aluminum material 1. 【0128】 In step (II), the temperature (heating temperature) during the heat treatment of the composition layer 120 is preferably 90 to 240°C, more preferably 100 to 230°C, and particularly preferably 140 to 210°C. A heating temperature above the lower limit results in a greater amount of treated layer 12 being formed. A heating temperature below the upper limit results in a greater effect in suppressing the deterioration of the treated layer 12. 【0129】 In step (II), the time for heating layer 120 of the composition (heating time) is not particularly limited and can be adjusted as appropriate, taking into consideration the heating temperature, etc. Typically, the heating time is preferably 3 to 15 minutes, more preferably 4 to 12 minutes, and particularly preferably 5 to 10 minutes. A heating time above the lower limit results in a greater amount of the processed layer 12 being formed. A heating time below the upper limit reduces the time required for step (II). Such heating times are particularly preferable when the heating temperature falls within the above numerical range. 【0130】 In the surface-treated aluminum material 1, the use of the above composition prevents blackening. Furthermore, in step (I), by using the composition, one surface 11a of the aluminum material 11 can be more uniformly coated with the composition, thus preventing blackening with high uniformity in the surface-treated aluminum material 1, and forming a layer of the composition on one surface 11a of the aluminum material 11 with high uniformity, thereby enhancing the effectiveness of the blackening prevention treatment in the surface-treated aluminum material 1. 【0131】 The method for manufacturing the surface-treated aluminum material 1 may include, if necessary, other steps besides steps (I) and (II) described above. The type of the other steps is not particularly limited as long as it does not impair the effects of the present invention, and can be arbitrarily selected according to the purpose. The timing of performing the other steps can also be appropriately selected according to the type of other steps. 【0132】 Up to this point, the manufacturing method has been explained using surface-treated aluminum material 1 shown in Figure 1 as an example of surface-treated aluminum material. However, other surface-treated aluminum materials can also be manufactured using the same method as described above. In this case, the manufacturing method for the relevant surface-treated aluminum material may include appropriate other steps at appropriate timings, based on the differences between that surface-treated aluminum material and surface-treated aluminum material 1 shown in Figure 1. 【0133】 For example, when manufacturing the surface-treated aluminum material 2 shown in Figure 2, the composition may be applied simultaneously to one surface 11a and the other surface 11b of the aluminum material 11, or the composition may be applied to one surface 11a and the other surface 11b of the aluminum material 11 in stages. [Examples] 【0134】 The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited in any way to the examples shown below. 【0135】 The raw materials used in each example and comparative example are shown below. [Amino resin (A)] (A)-1: Melamine resin (DIC Corporation's "Watersol (registered trademark) S-695") [Acid catalyst (B)] (B)-1: Alkyl phosphate (NACURE 4000, manufactured by KING INDUSTRIES) [Surfactants (C1)] (C1)-1: A compound represented by the following general formula (c)-11-1 (Emulsogen EL360, manufactured by Clariant, molecular weight 2100, HLB value 13). 【0136】 [ka] (In the formula, n1 is an integer greater than or equal to 2.) 【0137】 [Surfactant (C2)] (C2)-1: A compound represented by the following general formula (c)-21-1 ("GENAPOL X 050" manufactured by Clariant, molecular weight 405, HLB value 10.6). 【0138】 [ka] (In the formula, l1 is an integer greater than or equal to 2.) 【0139】 [Crosslinking agent (X)] (X)-1: Polyisocyanate (DIC Corporation's "DNW-5000") [Other surfactants (Y)] (Y)-1: A compound represented by the following general formula (y)-1-1 (Emulsogen COL080, manufactured by Clariant, molecular weight 688). 【0140】 [ka] (In the formula, t1 is an integer greater than or equal to 2.) 【0141】 [Example 1] <<Production of Compositions>> At room temperature, amino resin (A)-1 (3 moles), acid catalyst (B)-1 (2 moles), surfactant (C1)-1 (9 moles), surfactant (C2)-1 (1 mole), and water (0.2 L) were combined and mixed to obtain composition (1). The amounts of each component other than water shown here are the amounts of the target product excluding the solvent. In the obtained composition (1), the ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (1) was 2000 ppm. 【0142】 <<Manufacturing of surface-treated aluminum materials>> Using a spray washer, the composition (1) obtained above was sprayed onto the bottom surface of an aluminum can (outer diameter 66 mm, height 210 mm) to form a layer of composition (1) on the bottom surface of the aluminum can, and the composition (1) that did not form a layer was recovered (step (I)). Next, the layer of composition (1) was heat-treated at 180°C for 10 minutes to form a treated layer (2 nm thick) on the bottom surface of the aluminum can (step (II)). Based on the above, an aluminum can with a treated layer on its bottom surface (hereinafter sometimes referred to as a "bottom-treated aluminum can") was obtained using composition (1). 【0143】 <<Evaluation of the composition>> <Evaluation of the effect of the composition on preventing blackening in surface-treated aluminum materials> The bottom-treated aluminum cans (aluminum cans with surface-treated bottoms) obtained above were further heat-treated at 85°C or higher for 30 minutes. Next, the surface-treated bottoms of the aluminum cans after this heat treatment were visually observed, and the blackening prevention effect of composition (1) on the bottom-treated aluminum cans was evaluated according to the following criteria. The results are shown in the "Blackening Prevention Effect" column in Table 1. (Evaluation Criteria) A: The surface-treated bottom of the aluminum can did not blacken at all after heat treatment, indicating that the composition had a high blackening prevention effect. B: The treated bottom surface of the aluminum can was slightly blackened by the heat treatment, and the composition's blackening prevention effect was observed, but it was inferior to that of case "A". C: The surface-treated bottom of the aluminum can was significantly blackened by the heat treatment, and the composition's effect in preventing blackening was not observed. 【0144】 <Evaluation of the effect of the composition on improving the wettability of surface-treated aluminum materials> The composition (1) obtained above was dropped onto the surface of an aluminum plate at room temperature, spread using a bar coater, and heat-treated at 180°C for 5 minutes. Next, the surface-treated aluminum plate was visually inspected, and the wettability-improving effect of composition (1) was evaluated according to the following criteria. The results are shown in the "Wettability-improving effect" column in Table 1. (Evaluation Criteria) A: The surface of the aluminum plate was uniformly wetted, no water repellency was observed, and the composition had a high wettability-improving effect. B: The surface of the aluminum plate was wet, but water repellency was observed, indicating that the composition had an effect in improving wettability, but it was inferior to case "A". C: Significant repellency was observed on the surface of the aluminum plate, and the composition's effect on improving wettability was not observed. 【0145】 <Evaluation of the foam-suppressing effect of the composition> The composition (1) (0.2 L) obtained above was stirred in a 0.5 L container at room temperature at a stirring speed of 1500 rpm for 5 minutes, and then allowed to stand. The foaming suppression effect of composition (1) was then evaluated according to the following criteria. The results are shown in the "Foaming Suppression Effect" column in Table 1. (Evaluation Criteria) A: All the bubbles in the container were contained within the 150 mL or less marked area of ​​the container, indicating that the composition had a high foam-suppressing effect. B: Some of the foam in the container was present in the area between 150 mL and 250 mL on the container's scale, and the foam-suppressing effect of the composition was observed, but it was inferior to that of case "A". C: Some of the foam in the container was present in the area of ​​the container's markings exceeding 250 mL, indicating that the foam-suppressing effect of the composition was low. 【0146】 <<Production of compositions, production of surface-treated aluminum materials, evaluation of compositions>> [Example 2] Composition (2) was prepared in the same manner as in Example 1, except that the amount of amino resin (A)-1 was changed from 3 moles to 10 moles. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (2) in the obtained composition (2) was 2000 ppm. 【0147】 Except for using composition (2) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (2) was evaluated. The results are shown in Table 1. 【0148】 [Example 3] Composition (3) was prepared in the same manner as in Example 1, except that the amount of surfactant (C1)-1 was changed from 9 moles to 8 moles, and the amount of surfactant (C2)-1 was changed from 1 mole to 2 moles. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (3) in the obtained composition (3) was 2000 ppm. 【0149】 Except for using composition (3) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (3) was evaluated. The results are shown in Table 1. 【0150】 [Example 4] Composition (4) was prepared in the same manner as in Example 1, except that acid catalyst (B)-1 (2 moles) and surfactant (C2)-1 (1 mole) were not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (4) in the obtained composition (4) was 2000 ppm. 【0151】 Except for using composition (4) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (4) was evaluated. The results are shown in Table 1. 【0152】 [Example 5] Composition (5) was prepared in the same manner as in Example 1, except that surfactant (C2)-1 (1 mole) was not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (5) in the obtained composition (5) was 2000 ppm. 【0153】 Except for using composition (5) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (5) was evaluated. The results are shown in Table 1. 【0154】 [Example 6] Composition (6) was prepared in the same manner as in Example 1, except that acid catalyst (B)-1 (2 moles) was not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (6) in the obtained composition (6) was 2000 ppm. 【0155】 Except for using composition (6) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (6) was evaluated. The results are shown in Table 1. 【0156】 [Example 7] Composition (7) was prepared in the same manner as in Example 1, except that acid catalyst (B)-1 (2 moles) and surfactant (C1)-1 (9 moles) were not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (7) in the obtained composition (7) was 2000 ppm. 【0157】 Except for using composition (7) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (7) was evaluated. The results are shown in Table 1. 【0158】 [Example 8] Composition (8) was prepared in the same manner as in Example 1, except that surfactant (C1)-1 (9 mol) was not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (8) in the obtained composition (8) was 2000 ppm. 【0159】 Except for using composition (8) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (8) was evaluated. The results are shown in Table 1. 【0160】 [Comparative Example 1] Composition (R1) was obtained by blending and mixing amino resin (A)-1 (3 moles), another surfactant (Y)-1 (9 moles), and water (0.2 L) at room temperature. The amounts of each component other than water shown here are all amounts of the target product excluding the solvent. In the obtained composition (R1), the ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (R1) was 2000 ppm. 【0161】 Except for using composition (R1) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (R1) was evaluated. The results are shown in Table 2. 【0162】 [Comparative Example 2] Except for using crosslinking agent (X)-1 (3 moles) instead of composition (1) as the composition for treating the bottom surface of the aluminum can, a treated layer (2 nm thick) was formed on the bottom surface of the aluminum can in the same manner as in Example 1, and the bottom-treated aluminum can was manufactured and the composition (i.e., crosslinking agent (X)-1) was evaluated. The results are shown in Table 2. 【0163】 [Comparative Example 3] Composition (R2) was prepared in the same manner as in Example 1, except that amino resin (A)-1 (3 moles) was not included and the amount of acid catalyst (B)-1 was changed from 2 moles to 1 mole. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (R2) in the obtained composition (R2) was 2000 ppm. 【0164】 Except for using composition (R2) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (R2) was evaluated. The results are shown in Table 2. 【0165】 [Comparative Example 4] Composition (R3) was prepared in the same manner as in Example 1, except that amino resin (A)-1 (3 moles) and acid catalyst (B)-1 (2 moles) were not included. The ratio of the total content (parts by mass) of components other than the solvent to the total mass of composition (R3) in the obtained composition (R3) was 2000 ppm. 【0166】 Except for using composition (R3) obtained above instead of composition (1), a treatment layer (2 nm thick) was formed on the bottom surface of an aluminum can in the same manner as in Example 1, and a bottom-treated aluminum can was manufactured and composition (R3) was evaluated. The results are shown in Table 2. 【0167】 [Comparative Example 5] Except for using surfactant (C1)-1 (9 moles) instead of composition (1) as the composition for treating the bottom surface of the aluminum can, a treatment layer (2 nm thick) was formed on the bottom surface of the aluminum can in the same manner as in Example 1, and the bottom-treated aluminum can was manufactured, and the composition (i.e., surfactant (C1)-1) was evaluated. The results are shown in Table 2. 【0168】 [Comparative Example 6] Except for using amino resin (A)-1 (3 moles) instead of composition (1) as the composition for treating the bottom surface of the aluminum can, a treatment layer (2 nm thick) was formed on the bottom surface of the aluminum can in the same manner as in Example 1, and the bottom-treated aluminum can was manufactured and the composition (i.e., amino resin (A)-1) was evaluated. The results are shown in Table 2. 【0169】 [Comparative Example 7] Except for using another surfactant (Y)-1 (9 moles) instead of composition (1) as the composition for treating the bottom surface of the aluminum can, a treatment layer (2 nm thick) was formed on the bottom surface of the aluminum can in the same manner as in Example 1, and the bottom-treated aluminum can was manufactured and the composition (i.e., the other surfactant (Y)-1) was evaluated. The results are shown in Table 2. 【0170】 [Comparative Example 8] Except for using surfactant (C2)-1 (1 mole) instead of composition (1) as the composition for treating the bottom surface of the aluminum can, a treatment layer (2 nm thick) was formed on the bottom surface of the aluminum can in the same manner as in Example 1, and the bottom-treated aluminum can was manufactured, and the composition (i.e., surfactant (C2)-1) was evaluated. The results are shown in Table 2. 【0171】 [Table 1] 【0172】 [Table 2] 【0173】 As is clear from the results above, in Examples 1 to 8, blackening was prevented on the surface-treated bottom of the aluminum can, the wettability of the aluminum plate was improved, and foaming of compositions (1) to (8) was suppressed. Compositions (1) to (8) in Examples 1 to 8 all contained an amino resin (A) and a nonionic surfactant (C). 【0174】 In particular, in Examples 1 to 3, the blackening prevention effect on the surface-treated bottom of aluminum cans, the wettability improvement effect on the surface of aluminum plates, and the foaming suppression effect of compositions (1) to (3) were all high, and remarkable effects were confirmed. Compositions (1) to (3) in Examples 1 to 3 all contained amino resin (A), acid catalyst (B), surfactant (C1), and surfactant (C2). 【0175】 In contrast, in Comparative Examples 1 to 8, one or more of the following effects were not observed or were low: an effect of preventing blackening on the surface-treated bottom of the aluminum can, an effect of improving the wettability of the aluminum plate surface, and an effect of suppressing foaming of the composition. In Comparative Examples 1 and 6, neither composition (R1) nor composition (i.e., amino resin (A)-1) contained a nonionic surfactant (C). The compositions in Comparative Examples 2 and 7 (i.e., crosslinking agent (X)-1 and other surfactant (Y)-1) did not contain either an amino resin (A) or a nonionic surfactant (C). In Comparative Examples 3-5 and 8, compositions (R2)-(R3) and composition (i.e., surfactant (C1)-1 and surfactant (C2)-1) did not contain amino resin (A). 【0176】 In particular, in Comparative Examples 2 and 7, which did not use either amino resin (A) or nonionic surfactant (C), neither the effect of preventing blackening on the surface-treated bottom of the aluminum can nor the effect of improving the wettability of the aluminum plate surface was observed, and the effect was the worst. 【0177】 In Comparative Example 5, unlike the other examples and comparative examples, a surfactant (C1) was used to treat the bottom surface of the aluminum can. However, the surfactant (C1) produced significant foaming and was not practically usable as is. In Comparative Example 5, a treatment layer was formed on the bottom surface of the aluminum can without considering practicality. As a result, blackening was not prevented on the surface-treated bottom surface of the aluminum can. 【0178】 In Comparative Examples 1-2 and 6-7, the wettability of the aluminum cans was inferior to that of the other comparative examples. In Comparative Examples 1-2 and 6-7, the compositions did not contain nonionic surfactant (C). [Industrial applicability] 【0179】 This invention can be used for both preventing blackening and improving the wettability of various aluminum materials, including aluminum cans, and the composition used in these treatments has suppressed foaming. [Explanation of Symbols] 【0180】 1,2...Surface-treated aluminum material, 11...Aluminum material, 11a...One side (surface) of the aluminum material, 11b...The other side (surface) of the aluminum material, 12...Treatment layer, 121...First treatment layer, 122...Second treatment layer, 120...Layer of composition

Claims

[Claim 1] A composition used when forming a treatment layer on the surface of an aluminum material for preventing blackening and improving wettability, It contains an amino resin (A) and a nonionic surfactant (C), and further contains an acid catalyst (B), The nonionic surfactant (C) contains either one or both of surfactant (C1) and surfactant (C2), The surfactant (C1) is an ester of a hydroxyl group-containing fatty acid and glycerin, in which one or more hydroxyl groups are of the following general formula (i): -O(R 11 O)nH (i) (In the formula, n is an integer greater than or equal to 2; R11 is an alkylene group, and the n R11 groups may be identical or different from each other.) It has a structure substituted with a group represented by (however, if two or more of the hydroxyl groups are substituted with a group represented by the general formula (i), these two or more groups represented by the general formula (i) may be the same or different from each other), A composition in which the surfactant (C2) has either an oxyethylene group or an oxypropylene group, or both. [Claim 2] The composition according to claim 1, wherein the amino resin (A) is a melamine resin. [Claim 3] The composition according to claim 1 or 2, wherein the molecular weight of the surfactant (C1) is 800 or more. [Claim 4] The composition according to claim 1 or 2, wherein the surfactant (C2) is polyethylene glycol monoalkyl ether. [Claim 5] The composition according to any one of claims 1 to 4, wherein the acid catalyst (B) is one or more selected from the group consisting of phosphoric acid, phosphoric acid derivatives, and sulfonic acid. [Claim 6] A surface-treated aluminum material comprising an aluminum material and a treatment layer provided on the surface of the aluminum material, A surface-treated aluminum material wherein the treatment layer is a reactant of the composition described in any one of claims 1 to 5. [Claim 7] A method for manufacturing a surface-treated aluminum material comprising an aluminum material and a treatment layer provided on the surface of the aluminum material, The manufacturing method includes a step (I) of forming a layer of the composition on the surface of the aluminum material using the composition described in any one of claims 1 to 5, A method for producing a surface-treated aluminum material, comprising the step (II) of forming the treatment layer, which is a reactant of the composition, on the surface of the aluminum material by heat-treating a layer of the composition. [Claim 8] The aforementioned aluminum material is an aluminum can. The method for producing a surface-treated aluminum material according to claim 7, wherein in step (I), the composition is sprayed onto one or more of the bottom, side, and inner surfaces of the aluminum can using a spray washer to form a layer of the composition, and the composition that did not form a layer of the composition is recovered.