Antibacterial household aluminum foil and production process thereof

Abstract

This invention relates to an antibacterial household aluminum foil and its manufacturing process. The aluminum foil includes a substrate layer and a coating applied to at least one surface of the substrate layer. The weight percentages of the raw materials in the substrate layer are as follows: Si 0.5-0.6%, Fe 0.7-0.8%, Cu 0.1-0.2%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.01-0.06%, with the balance being Al. The coating is an antibacterial coating containing composite powder and antibacterial powder in a ratio of (3-5):1. The composite powder includes graphene and linear nano-zinc oxide in a mass ratio of 10:(1-3). By adding Cu to the substrate layer, the density of the substrate layer can be enhanced and the antibacterial properties of the aluminum foil can be improved. By controlling the roughness of the rolls, the smoothness of the substrate layer surface can be ensured, thereby reducing bacterial growth. A coating with antibacterial properties is applied to the other side of the substrate layer, which further improves the antibacterial properties of the other side of the aluminum foil, thus improving the overall antibacterial properties of the aluminum foil.

Description

Technical Field

[0001] This invention relates to the field of aluminum foil production technology, specifically to an antibacterial household aluminum foil and its production process. Background Technology

[0002] Aluminum foil is a flexible metal film that not only possesses properties such as moisture resistance, airtightness, light blocking, corrosion resistance, aroma retention, and non-toxicity and odorlessness, but also has an elegant silvery-white luster and is easily processed into various colors and patterns. Therefore, aluminum foil is widely used in food, beverages, cigarettes, pharmaceuticals, and household goods. In the household goods sector, aluminum foil is often used to wrap or come into contact with solid food, which places higher demands on its antibacterial and other properties. However, as a metallic material, adding inorganic or organic antibacterial agents during the aluminum foil casting process can affect product quality, thus significantly limiting improvements in the antibacterial properties of aluminum foil. Summary of the Invention

[0003] This invention provides an antibacterial household aluminum foil and its manufacturing process to solve the above-mentioned problems.

[0004] The technical solution adopted in this invention is: an antibacterial household aluminum foil, which includes a substrate layer and a coating applied to at least one side of the substrate layer;

[0005] The weight percentages of each raw material in the substrate layer are as follows: Si 0.5-0.6%, Fe 0.7-0.8%, Cu 0.1-0.2%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.01-0.06%, with the balance being Al;

[0006] The coating is an antibacterial coating, which contains composite powder and antibacterial powder in a ratio of (3-5):1.

[0007] Preferably, the composite powder comprises graphene and linear nano-zinc oxide in a mass ratio of 10:(1-3).

[0008] Preferably, the method for preparing the antibacterial powder is as follows: Carboxymethyl chitosan and a silane compound are added to water, along with a catalyst, wherein the mass ratio of carboxymethyl chitosan to the silane compound and tin tetrachloride is 10:(8-15):(1-2.5), and the mixture is reacted at 75-90℃ for 3-5 hours to obtain silanized chitosan; then, the silanized chitosan is added to dichloromethane, along with nano-silica, and the mixture is reacted at 30-45℃ for 3 hours to obtain the antibacterial powder, wherein the mass ratio of silanized chitosan to nano-silica is 1:8-30.

[0009] Preferably, the catalyst is tin tetrachloride, and the chemical formula of the silane compound is (CH3O)3Si(CH2)3O(CH2)2OH.

[0010] On the other hand, the invention also provides a manufacturing process for the aluminum foil, which includes at least the following steps:

[0011] S1: Preparation of substrate layer, composite powder and antibacterial powder;

[0012] S2: Preparation of composite powder and antibacterial powder;

[0013] S3: Apply adhesive to the surface of the substrate layer, and then apply the composite powder and antibacterial powder mixed evenly to one side of the substrate layer.

[0014] Preferably, the preparation of the substrate layer in step S1 includes at least the following steps:

[0015] A1: Weigh the raw materials according to the mass ratio and mix them evenly. After melting and refining, the mixture is formed into an ingot.

[0016] A2: Hot-rolled coils are obtained by hot rolling ingots at 500-550℃.

[0017] A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0mm to obtain a single-stage cold-rolled billet;

[0018] A4: Homogenization annealing: Hold the cold-rolled billet at 540℃ for 20 hours, with a heating time of 3-5 hours;

[0019] A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2-0.3mm;

[0020] A6: Foil rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During the foil rolling process, rolling oil is sprayed onto the rolls.

[0021] A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h.

[0022] Preferably, the roll roughness in step A2 is 0.6-0.9 μm; the roll roughness in step A3 is 0.4-0.5 μm; the roll roughness in step A5 is 0.35-0.4 μm; in step A6, when the billet thickness is 0.1 mm or more, the roll roughness used in that pass is 0.25-0.26 μm; when the billet thickness is 0.09-0.04 mm, the roll roughness used in that pass is 0.17-0.18 μm; and the roll roughness used in the final pass is 0.12-0.13 μm.

[0023] Preferably, the rolling oil has a kinematic viscosity of less than 1.95 mm² / s at 40°C, an acid value of less than 0.4 mg KOH / g, a saponification value of less than 10 mg KOH / g, a hydroxyl value of less than 5 mg KOH / g, and a light transmittance of ≥98%.

[0024] Preferably, in step A7, the width of the finished aluminum foil is d. When d ≤ 300 mm, the heat preservation time is 24-30 h; when d is 290-500 mm, the heat preservation time is 30-50 h; and when d is 510-1000 mm, the heat preservation time is 70-80 h.

[0025] Preferably, the composite powder preparation method is as follows: graphene and linear nano zinc oxide are coarsely ground and finely ground using a dry powder ball mill. The grinding speed for coarse grinding is 2000-3000 rpm and the grinding time is 0.5-1.5 h. The grinding speed for fine grinding is 3000-3300 rpm and the grinding time is 3-3.5 h.

[0026] Compared with the prior art, the present invention has the following advantages: (1) By adding Cu element to the substrate layer, the density of the substrate layer can be enhanced and the antibacterial performance of the aluminum foil can be improved; (2) During the preparation of the substrate layer, the smoothness of one side of the substrate layer is ensured by controlling the roughness of the roller throughout the process, thereby reducing the growth of bacteria. The other side of the substrate layer is coated with a coating, which has certain antibacterial properties, thereby improving the antibacterial performance of the other side of the aluminum foil, thus improving the overall antibacterial performance of the aluminum foil; (3) The three-dimensional graphene structure can better capture bacteria, while the linear nano zinc oxide utilizes the linear structure of the linear zinc oxide to pierce bacterial cells, thereby destroying the cell membrane and further improving the antibacterial function; (4) The active hydroxyl groups on the nano silica react with silanized chitosan, thereby making the silanized chitosan crosslinked on the surface of the nano silica, thus producing antibacterial powder. On the one hand, the dispersibility of the nano silica is improved, and on the other hand, the antibacterial performance is improved by introducing chitosan molecules. Detailed Implementation

[0027] To better illustrate the present invention, it will now be further described in conjunction with examples.

[0028] An antibacterial household aluminum foil includes a substrate layer and a coating applied to at least one surface of the substrate layer. The substrate layer comprises the following raw materials in weight percentage: Si 0.5-0.6%, Fe 0.7-0.8%, Cu 0.1-0.2%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.01-0.06%, with the balance being Al. The coating is an antibacterial coating containing composite powder and antibacterial powder in a ratio of (3-5):1. The addition of Cu to the substrate layer enhances its density and improves the antibacterial properties of the aluminum foil.

[0029] Preferably, the composite powder comprises graphene and linear zinc oxide nanoparticles in a mass ratio of 10:(1-3). Graphene can be either two-dimensional or three-dimensional, with a preference for three-dimensional graphene. Three-dimensional graphene can be prepared using 3D printing, wet chemical technology, or chemical vapor deposition, which are existing technologies and will not be detailed here. The three-dimensional graphene structure allows for better capture of bacteria. Linear zinc oxide nanoparticles, i.e., zinc oxide nanowires, are also existing technologies that can be purchased or manufactured. Zinc oxide itself has a certain antibacterial effect, and by selecting linear zinc oxide nanoparticles and specifically restricting their shape, the linear structure of the zinc oxide is utilized to pierce bacterial cells, thereby disrupting the cell membrane and further enhancing the antibacterial function.

[0030] Preferably, the method for preparing the antibacterial powder is as follows: Carboxymethyl chitosan and a silane compound are added to water, along with a catalyst. The mass ratio of carboxymethyl chitosan to the silane compound and tin tetrachloride is 10:(8-15):(1-2.5). The mixture undergoes a dehydration esterification reaction at 75-90°C for 3-5 hours to obtain silanized chitosan. Then, the silanized chitosan is added to dichloromethane, along with nano-silica, and the reaction is carried out at 30-45°C for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:8-30. The catalyst is tin tetrachloride, and the silane compound has the chemical formula (CH3O)3Si(CH2)3O(CH2)2OH. The antibacterial powder prepared by this method reacts the active hydroxyl groups on nano-silica with silanized chitosan, thereby crosslinking the silanized chitosan onto the surface of nano-silica. On the one hand, this improves the dispersibility of nano-silica, and on the other hand, it also enhances its antibacterial properties through the introduction of chitosan molecules.

[0031] On the other hand, the invention also provides a manufacturing process for the aluminum foil, which includes at least the following steps:

[0032] S1: Preparation of the substrate layer;

[0033] S2: Preparation of composite powder and antibacterial powder;

[0034] S3: Apply an adhesive to the surface of the substrate layer, and then apply a mixture of composite powder and antibacterial powder evenly to one side of the substrate layer. The adhesive can be selected according to actual needs, and polyurethane adhesive is preferred.

[0035] Preferably, the preparation of the substrate layer in step S1 includes at least the following steps:

[0036] A1: Weigh the raw materials according to the mass ratio and mix them evenly. After melting and refining, the mixture is formed into an ingot.

[0037] A2: Hot-rolled coils are obtained by hot rolling ingots at 500-550℃.

[0038] A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0mm to obtain a single-stage cold-rolled billet;

[0039] A4: Homogenization annealing: Hold the cold-rolled billet at 540℃ for 20 hours, with a heating time of 3-5 hours;

[0040] A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2-0.3mm;

[0041] A6: Foil rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During the foil rolling process, rolling oil is sprayed onto the rolls.

[0042] A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h.

[0043] Preferably, the roll roughness in step A2 is 0.6-0.9 μm; the roll roughness in step A3 is 0.4-0.5 μm; the roll roughness in step A5 is 0.35-0.4 μm; in step A6, when the billet thickness is 0.1 mm or more, the roll roughness used in that pass is 0.25-0.26 μm; when the billet thickness is 0.09-0.04 mm, the roll roughness used in that pass is 0.17-0.18 μm; and the roll roughness used in the final pass is 0.12-0.13 μm. By controlling the roll roughness in each step, the surface finish of the substrate layer on the side in contact with the roll can be increased, thereby reducing bacterial growth. The coating can be applied to one or both sides of the substrate layer. Preferably, the coating is applied to the side of the substrate layer that is not in contact with the rolls. This makes one side of the aluminum foil have been processed by cold rolling and foil rolling. By controlling the roughness of the rolls, the smoothness of the surface of the aluminum foil on this side is ensured, thereby reducing the growth of bacteria. The other side of the aluminum foil is coated with a coating that has certain antibacterial properties, thereby improving the antibacterial properties of the other side of the aluminum foil, thus improving the overall antibacterial properties of the aluminum foil.

[0044] Preferably, the rolling oil has a kinematic viscosity of less than 1.95 mm² / s at 40°C, an acid value of less than 0.4 mg KOH / g, a saponification value of less than 10 mg KOH / g, a hydroxyl value of less than 5 mg KOH / g, and a light transmittance of ≥98%.

[0045] Preferably, in step A7, the width of the finished aluminum foil is d. When d ≤ 300 mm, the holding time is 24-30 h; when d is 290-500 mm, the holding time is 30-50 h; and when d is 510-1000 mm, the holding time is 70-80 h. By extending the holding time and increasing the annealing temperature, complete removal of rolling oil can be ensured, thereby reducing the risk of bacterial growth. Furthermore, selecting an appropriate holding time based on the different dimensions of the finished product facilitates the assurance of the product's mechanical properties.

[0046] Preferably, the composite powder preparation method is as follows: graphene and linear nano-zinc oxide are coarsely ground and finely ground using a dry powder ball mill. The coarse grinding speed is 2000-3000 rpm and the grinding time is 0.5-1.5 h, while the fine grinding speed is 3000-3300 rpm and the grinding time is 3-3.5 h. By performing coarse and fine grinding on graphene and linear nano-zinc oxide, sufficient contact and displacement between the two are facilitated, further enhancing the antibacterial function of the composite powder.

[0047] Example 1

[0048] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: applying an adhesive to the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and applying it to the substrate layer. The ratio of the composite powder to the antibacterial powder is 3:1.

[0049] The preparation of the substrate layer in step S1 includes at least the following steps:

[0050] A1: The weight percentages of each raw material in the substrate layer are as follows: Si 0.5%, Fe 0.8%, Cu 0.1%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.06%, with the balance being Al; the raw materials are weighed according to the above mass ratio and mixed evenly, and then smelted and refined to form an ingot;

[0051] A2: The ingot is hot-rolled at 500℃ to obtain hot-rolled coils. The roll roughness during the hot rolling process is 0.6μm.

[0052] A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0 mm to obtain a single-stage cold-rolled billet. The roughness of the rolls during the single-stage cold rolling process is 0.45 μm.

[0053] A4: Homogenization annealing: The cold-rolled billet is held at 540℃ for 20 hours, and the heating time is 4 hours.

[0054] A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2-0.3mm. During this process, the roughness of the rolls is 0.38μm.

[0055] A6: Foil Rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During foil rolling, rolling oil is sprayed onto the rolls. The roll roughness is limited according to the different blank thicknesses in each pass. When the blank thickness is 0.1 mm or more, the roll roughness used in that pass is 0.25 μm; when the blank thickness is 0.09-0.04 mm, the roll roughness used in that pass is 0.17 μm; and the roll roughness used in the final pass at the end of foil rolling is 0.12 μm. The rolling oil has a kinematic viscosity of less than 1.95 mm² / s at 40°C, an acid value of less than 0.4 mg KOH / g, a saponification value of less than 10 mg KOH / g, a hydroxyl value of less than 5 mg KOH / g, and a light transmittance of ≥98%.

[0056] A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h. The width of the finished aluminum foil is d. When d≤300mm, the holding time is 30h; when d is 290-500mm, the holding time is 30h; and when d is 510-1000mm, the holding time is 70h.

[0057] The composite powder preparation method in step S2 is as follows: Graphene and linear nano zinc oxide are weighed and mixed in a mass ratio of 10:2. The mixed raw materials are coarsely ground and finely ground using a dry powder ball mill. The grinding speed for coarse grinding is 2000 rpm and the grinding time is 1.5 h. The grinding speed for fine grinding is 3000 rpm and the grinding time is 3.5 h.

[0058] The antibacterial powder is prepared as follows: Carboxymethyl chitosan and a silane compound are added to water, along with a catalyst. The mass ratio of carboxymethyl chitosan to the silane compound and tin tetrachloride is 10:12:1.8. The mixture undergoes a dehydration esterification reaction at 75°C for 5 hours to obtain silanized chitosan. Next, the silanized chitosan is added to dichloromethane, along with nano-silica, and the reaction is carried out at 30°C for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:30. The catalyst is tin tetrachloride, and the silane compound has the chemical formula (CH3O)3Si(CH2)3O(CH2)2OH.

[0059] Example 2

[0060] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: applying an adhesive to the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and applying it to the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 5:1.

[0061] The preparation of the substrate layer in step S1 includes at least the following steps:

[0062] A1: The weight percentages of each raw material in the substrate layer are as follows: Si 0.6%, Fe 0.7%, Cu 0.2%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.01%, with the balance being Al; the raw materials are weighed according to the above mass ratio and mixed evenly, and then smelted and refined to form an ingot;

[0063] A2: The ingot is hot-rolled at 550℃ to obtain hot-rolled coils. The roll roughness during the hot rolling process is 0.9μm.

[0064] A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0 mm to obtain a single-stage cold-rolled billet. The roughness of the rolls during the single-stage cold rolling process is 0.5 μm.

[0065] A4: Homogenization annealing: Hold the cold-rolled billet at 540℃ for 20 hours, with a heating time of 3-5 hours;

[0066] A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2 mm. During this process, the roughness of the rolls is 0.4 μm.

[0067] A6: Foil Rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During foil rolling, rolling oil is sprayed onto the rolls. The roll roughness is limited according to the different blank thicknesses in each pass. When the blank thickness is 0.1 mm or more, the roll roughness used in that pass is 0.26 μm; when the blank thickness is 0.09-0.04 mm, the roll roughness used in that pass is 0.18 μm; and the roll roughness used in the final pass at the end of foil rolling is 0.12 μm. The rolling oil has a kinematic viscosity of less than 1.95 mm² / s at 40°C, an acid value of less than 0.4 mg KOH / g, a saponification value of less than 10 mg KOH / g, a hydroxyl value of less than 5 mg KOH / g, and a light transmittance of ≥98%.

[0068] A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h. The width of the finished aluminum foil is d. When d≤300mm, the holding time is 24h; when d is 290-500mm, the holding time is 50h; and when d is 510-1000mm, the holding time is 80h.

[0069] The composite powder preparation method in step S2 is as follows: Graphene and linear nano zinc oxide are weighed and mixed in a mass ratio of 10:1. The mixed raw materials are coarsely ground and finely ground using a dry powder ball mill. The grinding speed for coarse grinding is 3000 rpm and the grinding time is 0.5 h. The grinding speed for fine grinding is 3300 rpm and the grinding time is 3 h.

[0070] The method for preparing the antibacterial powder is as follows: Carboxymethyl chitosan and a silane compound are added to water, along with a catalyst. The mass ratio of carboxymethyl chitosan to the silane compound and tin tetrachloride is 10:8:1. The mixture undergoes a dehydration esterification reaction at 90°C for 3 hours to obtain silanized chitosan. Next, the silanized chitosan is added to dichloromethane, along with nano-silica, and the reaction is carried out at 45°C for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:8. The catalyst is tin tetrachloride, and the chemical formula of the silane compound is (CH3O)3Si(CH2)3O(CH2)2OH.

[0071] Example 3

[0072] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: applying an adhesive to the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and applying it to the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 4:1.

[0073] The preparation of the substrate layer in step S1 includes at least the following steps:

[0074] A1: The weight percentages of each raw material in the substrate layer are as follows: Si 0.58%, Fe 0.75%, Cu 0.15%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.04%, with the balance being Al; the raw materials are weighed according to the above mass ratio and mixed evenly, and then smelted and refined to form an ingot;

[0075] A2: The ingot is hot-rolled at 530℃ to obtain hot-rolled coils. The roll roughness during the hot rolling process is 0.8μm.

[0076] A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0 mm to obtain a single-stage cold-rolled billet. The roughness of the rolls during the single-stage cold rolling process is 0.4 μm.

[0077] A4: Homogenization annealing: The cold-rolled billet is held at 540℃ for 20 hours, and the heating time is 5 hours.

[0078] A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2-0.3mm. During this process, the roughness of the rolls is 0.35μm.

[0079] A6: Foil Rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During foil rolling, rolling oil is sprayed onto the rolls. The roll roughness is limited according to the different blank thicknesses in each pass. When the blank thickness is 0.1 mm or more, the roll roughness used in that pass is 0.25 μm; when the blank thickness is 0.09-0.04 mm, the roll roughness used in that pass is 0.17 μm; and the roll roughness used in the final pass at the end of foil rolling is 0.13 μm. The rolling oil has a kinematic viscosity of less than 1.95 mm² / s at 40°C, an acid value of less than 0.4 mg KOH / g, a saponification value of less than 10 mg KOH / g, a hydroxyl value of less than 5 mg KOH / g, and a light transmittance of ≥98%.

[0080] A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h. The width of the finished aluminum foil is d. When d≤300mm, the holding time is 28h; when d is 290-500mm, the holding time is 40h; and when d is 510-1000mm, the holding time is 75h.

[0081] The composite powder preparation method in step S2 is as follows: graphene and linear nano zinc oxide are weighed and mixed in a mass ratio of 10:3. The mixed raw materials are coarsely ground and finely ground using a dry powder ball mill. The grinding speed for coarse grinding is 2500 rpm and the grinding time is 1.2 h. The grinding speed for fine grinding is 3100 rpm and the grinding time is 3.2 h.

[0082] The method for preparing the antibacterial powder is as follows: Carboxymethyl chitosan and a silane compound are added to water, along with a catalyst. The mass ratio of carboxymethyl chitosan to the silane compound and tin tetrachloride is 10:15:2.5. The mixture undergoes a dehydration esterification reaction at 80°C for 4 hours to obtain silanized chitosan. Then, the silanized chitosan is added to dichloromethane, along with nano-silica, and the reaction is carried out at 35°C for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:20. The catalyst is tin tetrachloride, and the chemical formula of the silane compound is (CH3O)3Si(CH2)3O(CH2)2OH.

[0083] Comparative Example 1

[0084] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating comprises a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: coating an adhesive onto one side of the substrate layer after foil rolling, and then uniformly mixing the composite powder and the antibacterial powder and coating it onto the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 4:1. The preparation methods of the substrate layer, the composite powder, and the antibacterial powder are the same as in Example 3.

[0085] Comparative Example 2

[0086] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: coating an adhesive on the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and coating it onto the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 4:1. The preparation method of the composite powder and the antibacterial powder is the same as in Example 3. The preparation method of the substrate layer is the same as in Example 3, except that the weight percentage of each raw material in the substrate layer is as follows: Si 0.58%, Fe 0.75%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.04%, and the balance is Al.

[0087] Comparative Example 3

[0088] An antibacterial household aluminum foil includes a substrate layer and a coating applied to one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: applying an adhesive to the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and applying it to the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 4:1.

[0089] The composite powder preparation method in step S2 is as follows: graphene and linear nano zinc oxide are weighed and mixed in a mass ratio of 10:3. The preparation method of antibacterial powder and substrate layer is the same as in Example 3.

[0090] Comparative Example 4

[0091] An antibacterial household aluminum foil includes a substrate layer and a coating on one side of the substrate layer. The coating includes a composite powder and an antibacterial powder. The preparation method of the aluminum foil includes the following steps: S1: preparing the substrate layer; S2: preparing the composite powder and the antibacterial powder; S3: coating an adhesive on the side of the substrate layer that has not undergone foil rolling treatment, and then uniformly mixing the composite powder and the antibacterial powder and coating it on the surface of the substrate layer. The ratio of the composite powder to the antibacterial powder is 4:1. The preparation methods of the substrate layer and the composite powder are the same as in Example 3. The preparation method of the antibacterial powder is as follows: carboxymethyl chitosan and a silane compound are mixed in a ratio of 2:3, and dehydrated and esterified at 80°C for 4 hours to obtain silanized chitosan; then the silanized chitosan is added to dichloromethane, and nano-silica is added, and reacted at 35°C for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:20. The catalyst is tin tetrachloride, and the chemical formula of the silane compound is (CH3O)3Si(CH2)3O(CH2)2OH.

[0092] Antibacterial performance test

[0093] The antibacterial properties of the aluminum foils prepared in Examples 1-3 and Comparative Examples 1-4 were tested according to the requirements of GB / T 31402-2015, and the test results are shown in Table 1.

[0094] Table 1

[0095] Example 1 99.7 99.8 Example 2 99.8 99.9 Example 3 99.8 99.9 Comparative Example 1 85.7 86.1 Comparative Example 2 90.4 90.7 Comparative Example 3 89.7 90.1 Comparative Example 4 80.5 81.3

[0096] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An antibacterial household aluminum foil, characterized in that: The aluminum foil includes a substrate layer and a coating applied to at least one surface of the substrate layer; The weight percentages of each raw material in the substrate layer are as follows: Si 0.5-0.6%, Fe 0.7-0.8%, Cu 0.1-0.2%, Mn 0.05%, Mg 0.05%, Zn 0.05%, Ti 0.01-0.06%, with the balance being Al; The coating is an antibacterial coating, which contains composite powder and antibacterial powder in a ratio of (3-5):

1. The composite powder comprises graphene and linear nano zinc oxide in a mass ratio of 10:(1-3). The manufacturing process of antibacterial household aluminum foil includes at least the following steps: S1: Prepare the substrate layer, which is subjected to cold rolling, foil rolling, and annealing. S2: Preparation of composite powder and antibacterial powder: The method for preparing the antibacterial powder is as follows: carboxymethyl chitosan and silane compound are added to water, and a catalyst is added. The mass ratio of carboxymethyl chitosan to silane compound and tin tetrachloride is 10:(8-15):(1-2.5). The mixture is reacted at 75-90℃ for 3-5 hours to obtain silanized chitosan. Then, silanized chitosan is added to dichloromethane, and nano-silica is added. The mixture is reacted at 30-45℃ for 3 hours to obtain the antibacterial powder. The mass ratio of silanized chitosan to nano-silica is 1:8-30. The composite powder preparation method is as follows: graphene and linear nano zinc oxide are coarsely ground and finely ground using a dry powder ball mill. The grinding speed for coarse grinding is 2000-3000 r / min and the grinding time is 0.5-1.5 h. The grinding speed for fine grinding is 3000-3300 r / min and the grinding time is 3-3.5 h. S3: Apply adhesive to the side of the substrate layer that has not undergone foil rolling treatment, and then apply a mixture of composite powder and antibacterial powder evenly to the side of the substrate layer.

2. The antibacterial household aluminum foil according to claim 1, characterized in that: The catalyst is tin tetrachloride, and the chemical formula of the silane compound is (CH3O)3Si(CH2)3O(CH2)2OH.

3. The antibacterial household aluminum foil according to claim 2, characterized in that: The preparation of the substrate layer in step S1 is at least Includes the following steps: A1: Weigh the raw materials according to the mass ratio and mix them evenly. After melting and refining, the mixture is formed into an ingot. A2: Hot-rolled coils are obtained by hot rolling ingots at 500-550℃. A3: Single-stage cold rolling: The hot-rolled coil is cold-rolled until the thickness of the coil is 2.5-3.0mm to obtain a single-stage cold-rolled billet; A4: Homogenization annealing: Hold the cold-rolled billet at 540℃ for 20 hours, with a heating time of 3-5 hours; A5: Secondary cold rolling: The billet after homogenization annealing is cold rolled until the billet thickness is 0.2-0.3mm; A6: Foil rolling: The blank after two cold rolling processes is foil rolled to obtain the finished product. During the foil rolling process, rolling oil is sprayed onto the rolls. A7: Finished product annealing: The temperature during the finished product annealing process is 200-280℃, and the holding time is 24-80h.

4. The antibacterial household aluminum foil according to claim 3, characterized in that: In step A2, the roughness of the roll is 0.6-0.9 μm; in step A3, the roughness of the roll is 0.4-0.5 μm; and in step A5, the roughness of the roll is 0.35-0.4 μm.

5. An antibacterial household aluminum foil according to claim 4, characterized in that: The rolling oil has a kinematic viscosity of less than 1.95 mm at 40°C. 2 / s, acid value less than 0.4 mgKOH / g, saponification value less than 10 mgKOH / g, hydroxyl value less than 5 mgKOH / g, and transmittance ≥98%.