阅读说明：本技术 一种锂电池软包装铝箔及其制备方法 (Lithium battery flexible package aluminum foil and preparation method thereof ) 是由 陈伟 赵丕植 付裕 郭世杰 马科 金晓杰 冯丹 于 2019-09-20 设计创作，主要内容包括：本发明提供了一种锂电池软包装铝箔及其制备方法,具体为利用半连续铸锭生产的铝箔坯料制备锂电池软包装铝箔及其制备方法。所述铝箔包括按质量百分比计的Fe 0.7％-1.7％,Si 0.05-0.1％,Cu小于0.05％,Mg小于0.05％,Ti小于0.01％,其它杂质元素合计小于0.15％,余量为Al。采用本发明方法制备的含上述组份的铝箔光面的轮廓算术平均偏差Ra在20-140nm范围内,铝箔的抗拉强度≥80MPa,铝箔的延伸率≥14％,铝箔与尼龙复合后的剥离强度大于6N/15mm。(The invention provides a lithium battery flexible packaging aluminum foil and a preparation method thereof, and particularly relates to a lithium battery flexible packaging aluminum foil prepared by utilizing aluminum foil blanks produced by semi-continuous ingot casting and a preparation method thereof. The aluminum foil comprises, by mass, 0.7% -1.7% of Fe, 0.05-0.1% of Si, less than 0.05% of Cu, less than 0.05% of Mg, less than 0.01% of Ti, less than 0.15% of other impurity elements in total, and the balance of Al. The arithmetic mean deviation Ra of the profile of the smooth surface of the aluminum foil containing the components prepared by the method is within the range of 20-140nm, the tensile strength of the aluminum foil is more than or equal to 80MPa, the elongation of the aluminum foil is more than or equal to 14 percent, and the peel strength of the aluminum foil and nylon after compounding is more than 6N/15 mm.)

1. The lithium battery flexible package aluminum foil is characterized by comprising 0.7-1.7% of Fe, 0.05-0.1% of Si, less than 0.05% of Cu, less than 0.05% of Mg, less than 0.01% of Ti, less than 0.15% of other impurity elements and the balance of Al.

2. The aluminum foil for the flexible package of the lithium battery as claimed in claim 1, wherein the aluminum foil is a single-sided smooth aluminum foil with a thickness of 20-60 μm, the arithmetic mean deviation Ra of the smooth profile of the aluminum foil is 20-140nm, the tensile strength of the aluminum foil is more than or equal to 80MPa, the elongation is more than or equal to 14%, and the peel strength of the aluminum foil after being compounded with nylon is more than 6N/15 mm.

3. The method for preparing the aluminum foil for the flexible package of the lithium battery as claimed in claim 1, wherein the method comprises the following steps:

(1) preparing a semi-continuous ingot;

(2) milling the obtained cast ingot, homogenizing, hot rolling and cold rolling to obtain an aluminum foil blank with the thickness of less than 1.0 mm;

(3) intermediate annealing the obtained aluminum foil blank;

(4) carrying out aluminum foil rolling on the annealed aluminum foil blank to obtain a single-sided polished aluminum foil;

(5) and annealing the obtained single-sided polished aluminum foil to obtain an O-state aluminum foil.

4. The method of manufacturing aluminum foil according to claim 3, wherein the O-state aluminum foil is 20 to 60 μm thick.

5. The method for preparing aluminum foil as claimed in claim 3, wherein in the step (2) of uniform treatment, the ingot is subjected to heat preservation at 610 ℃ for at least 6h at 550 ℃.

6. The method of manufacturing aluminum foil according to claim 3, wherein the aluminum foil of step (2)Blank materialThe thickness of (A) is 0.3-1.0 mm.

7. The method as claimed in claim 3, wherein the step (3) of intermediate annealing comprises treating the aluminum foil blank at 400 ℃ for 2-10h at 250 ℃.

8. The method for preparing aluminum foil according to claim 3, wherein in the rolling in the step (4), the rolling passes are 4-5, and the arithmetic mean deviation Ra of the axial profile of the working roll between each rolling pass is controlled, so that the arithmetic mean deviation Ra of the profile of the finished aluminum foil is controlled to be 20-140 nm.

9. The method as claimed in claim 3, wherein the step (5) of annealing the final aluminum foil includes degreasing and metal recrystallization, treating the aluminum foil at 250-350 ℃ for 40-80h, and then discharging and air cooling.

Technical Field

The invention relates to a lithium battery flexible package aluminum foil and a preparation method thereof, belonging to the technical field of nonferrous metal processing.

Background

With the rapid development of science and technology, the demand of the market for aluminum alloy is also rapidly increased. The aluminum alloy is widely applied to the fields of aerospace, electronic communication, war industry, medical treatment, mechanical manufacturing and the like. Aluminum foil plays an important role in the application of aluminum alloys. The aluminum foil has the characteristics of light weight, strong barrier property, high ductility, good forming property and the like, and is widely applied to the industries of packaging, electronics, electric appliances, buildings and the like.

The flexible package aluminum foil for the lithium battery aluminum plastic film is a pearl applied to the field of packaging of aluminum foils, and has very high requirements on the aluminum plastic film and various key materials for preparing the aluminum plastic film, particularly the aluminum foil, due to the requirements on the safety and the durability of the lithium battery. In the preparation process of the aluminum-plastic film, the aluminum foil is compounded with various materials such as nylon, polypropylene and the like through epoxy resin, and the quality of the compounding performance directly influences various performance indexes such as forming performance, heat resistance, heat sealing performance and the like of the aluminum-plastic film. For a long time, researchers have conducted a great deal of research on various factors affecting the composite performance of aluminum-plastic films, such as improving the performance of adhesive, performing physical and chemical surface treatment on the surface of each composite layer, improving the surface cleanliness of aluminum foils, and the like. The invention provides a process method for improving the compounding performance of an aluminum foil and other materials by controlling the roughness of the surface of the aluminum foil from the aspect of the surface appearance of the aluminum foil without increasing the preparation cost and the environmental protection pressure.

Disclosure of Invention

The invention aims to overcome the problem of poor composite performance of an aluminum plastic film, and provides a preparation method of a lithium battery flexible package aluminum foil with excellent peel strength from the aspect of controlling the surface appearance of the aluminum foil. The method comprises the following steps: homogenizing semi-continuous ingot casting, hot rolling, cold rolling, intermediate annealing, aluminum foil controlled rolling and finished product annealing.

The technical scheme of the invention is as follows:

a lithium battery flexible package aluminum foil with excellent peeling strength comprises the following elements in percentage by mass: 0.7 to 1.7 percent of Fe element, 0.05 to 0.1 percent of Si element, less than 0.05 percent of Cu element, less than 0.05 percent of Mg element, less than 0.01 percent of Ti, less than 0.15 percent of other impurity elements and the balance of Al.

A preparation method of a lithium battery flexible package aluminum foil with excellent peeling strength comprises the following steps:

1) homogenization treatment of semicontinuous ingot casting

And (4) carrying out end cutting and face milling processing on the semi-continuous cast ingot, wherein the face milling amount of the large face and the small face of the cast ingot is not less than 15 mm. And pushing the ingot into a box furnace for heating, keeping the temperature for more than 6 hours after the metal temperature reaches 550-610 ℃, and then reducing the temperature to the hot rolling temperature for hot rolling of the ingot.

2) Hot rolling

And lubricating and cooling by using the emulsion in the hot rolling process, and finishing the hot rolling above the recrystallization temperature, wherein the thickness of a hot-rolled plate is 3-7mm so as to reserve sufficient deformation for cold rolling.

3) Cold rolling

And cold rolling the hot rolled plate to obtain an aluminum foil blank with the thickness of 0.3-1.0 mm.

4) Intermediate annealing

And (3) carrying out intermediate annealing treatment on the aluminum foil blank, keeping the metal temperature at 250-400 ℃ for 2-10h, and completely recrystallizing the metal structure.

5) Rolling of aluminium foil

The arithmetic mean deviation Ra of the axial profiles of the aluminum foil rough rolling working roll, the intermediate rolling working roll and the finish rolling working roll is controlled step by step and respectively comprises the following steps: 100-200nm, 50-150nm and 20-100 nm. Thereby realizing the control of the arithmetic mean deviation of the surface profile of the aluminum foil.

6) Annealing of finished aluminum foil

And annealing the aluminum foil in a box-type furnace to obtain a finished product, controlling the metal temperature to be 250-350 ℃, keeping the temperature for 40-80h, and then discharging and air cooling.

Compared with the closest prior art, the technical scheme provided by the invention has the following excellent effects:

according to the method provided by the invention, the surface profile of the aluminum foil is controlled by accurately controlling the arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll of the aluminum foil, so that the excellent peeling strength after the aluminum foil and the nylon are compounded is realized.

Preparing a semi-continuous ingot casting in the aluminum foil preparation process; milling the cast ingot, homogenizing, hot rolling and cold rolling to obtain an aluminum foil blank with the thickness of less than 1.0 mm; carrying out intermediate annealing treatment on the aluminum foil blank; in the process of rolling the annealed aluminum foil blank to obtain a single-sided polished aluminum foil product and annealing the aluminum foil to obtain an O-state aluminum foil, the composite performance of the obtained aluminum foil meets the requirements by controlling and adjusting process parameters, and the aluminum foil with higher ductility and strength matching is obtained.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described with reference to specific embodiments, but the present invention is not limited to the scope of the present invention.

Example 1

The invention provides a lithium battery flexible package aluminum foil which is prepared from the following materials in percentage by mass:

0.055% of Si, 1.36% of Fe, 0.004% of Cu, 0.007% of Mn, 0.001% of Mg, 0.009% of Zn, 0.009% of Ti, and the balance of Al and inevitable impurities.

The preparation method of the aluminum foil comprises the following steps:

1) homogenizing semi-continuous cast ingot containing the component materials

And (2) sawing and milling a rectangular cast ingot obtained by semi-continuous casting, wherein the sawing amount of two ends of the rectangular cast ingot is not less than 30mm, the other four surfaces of the rectangular cast ingot are two large surfaces and two small surfaces respectively, the two large surfaces and the two small surfaces are milled respectively, uneven microscopic tissue layers on the surface of the cast ingot are removed, and the milling amount of each large surface and each small surface is not less than 15 mm. Then heated in a box furnace at 590 ℃ for 9h, and then cooled to the hot rolling temperature to hot-roll the ingot.

2) Hot rolling

And (2) carrying out hot rough rolling and hot finish rolling on the cast ingot by adopting 1+ N (N is more than or equal to 1) hot continuous rolling equipment, controlling the thickness of the plate to be 3.7mm when the rolling is started and the temperature of the plate to be not less than 250 ℃ when the rolling is finished, rolling, and slowly cooling the aluminum coil at room temperature. In order to ensure good lubrication, cooling and surface quality of the plate between a roller and the plate in the hot rolling process, water-based emulsion is adopted for lubrication, and the emulsion is at a temperature of between 45 and 65 ℃ and at a pH value of between 7 and 8 so as to prevent the plate from being corroded.

3) Cold rolling

And (2) cold rolling the hot rolled plate, controlling the rolling reduction of each pass to be between 30 and 60 percent, lubricating and cooling by using rolling oil, wherein the proportion of base oil in the rolling oil is not less than 95 percent, and simultaneously adding oily additives (such as organic acid, alcohol, ester and the like) which are not more than 5 percent to ensure that the surface of the plate is smooth and bright, so as to obtain an aluminum foil blank with the thickness of 0.6 mm.

4) Intermediate annealing

And heating the aluminum foil blank to 300 ℃ in a box type annealing furnace, and preserving heat for 8 hours for intermediate annealing so as to completely recrystallize the metal structure.

5) Rolling of aluminium foil

The interannealed 0.6mm thick aluminum foil stock was rolled four passes to 0.08mm under the following conditions: 0.6mm → 0.4mm → 0.3mm → 0.16mm → 0.08mm, rolling the 0.08mm aluminum foil together and then laminating to a single layer of 0.04mm thick aluminum foil; the arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll is controlled step by step in the aluminum foil rolling process and is respectively as follows: 100nm, 80nm and 50 nm. The arithmetic mean deviation Ra of the surface profile of the 0.08mm thick aluminum foil was 61 nm.

6) Annealing of finished aluminum foil

And (4) annealing the prepared aluminum foil in a box furnace to obtain a finished product, keeping the temperature of the aluminum foil at 250 ℃ for 60 hours, and then discharging the aluminum foil out of the furnace for air cooling.

The mechanical properties of the prepared aluminum foil are detected by an INSTRON aluminum foil tensile tester, the elongation of the prepared aluminum foil is detected by adopting a non-contact infrared sensor, the width of an aluminum foil sample is 15mm, the gauge length is 50mm, and the tensile speeds are 1mm/min (before yielding) and 3mm/min (after yielding) respectively. The aluminum foil is detected to have the tensile strength of 84.2MPa and the elongation of 15.3 percent.

After epoxy resin glue and nylon are compounded, the aluminum foil is cut into a sheet sample, and the specific process is as follows:

s1 gluing the surface of the aluminum foil: diluting the epoxy resin adhesive with ethyl acetate, dripping the diluted epoxy resin adhesive on the surface of an aluminum foil, uniformly coating the aluminum foil by using a wire bar coater, and drying in an oven to remove the ethyl acetate.

S2 aluminum foil-nylon compounding: and (3) compounding the aluminum foil dried in the step S1 and nylon at the temperature of 100 ℃ to obtain the aluminum-plastic composite film.

S3 curing: and (3) curing the aluminum-plastic composite film in the S2 in an oven at the temperature of 70 ℃ for 7 days.

And (3) carrying out T-shaped peeling detection on the aged aluminum-plastic film sample according to the GB8808, wherein the peel strength of the sample is 6.65N/15 mm.

Example 2

The procedure for preparing aluminum foil from the material of example 1 was as follows:

1) homogenizing semi-continuous ingot casting

And (2) sawing and milling a rectangular cast ingot obtained by semi-continuous casting, wherein the sawing amount of two ends of the rectangular cast ingot is not less than 30mm, the other four surfaces of the rectangular cast ingot are two large surfaces and two small surfaces respectively, the two large surfaces and the two small surfaces are milled respectively, uneven microscopic tissue layers on the surface of the cast ingot are removed, and the milling amount of each large surface and each small surface is not less than 15 mm. Then heating the ingot in a box furnace at 590 ℃ for 15h, and then reducing the temperature to the hot rolling temperature for hot rolling the ingot.

2) Hot rolling

And (2) carrying out hot rough rolling and hot finish rolling on the cast ingot by adopting 1+ N (N is more than or equal to 1) hot continuous rolling equipment, controlling the thickness of the plate to be 3.0mm when the rolling is started and the temperature of the plate to be not less than 250 ℃ when the rolling is finished, rolling, and slowly cooling the aluminum coil at room temperature. In order to ensure good lubrication, cooling and surface quality of the plate between a roller and the plate in the hot rolling process, water-based emulsion is adopted for lubrication, and the emulsion is at a temperature of between 45 and 65 ℃ and at a pH value of between 7 and 8 so as to prevent the plate from being corroded.

3) Cold rolling

And (2) cold rolling the hot rolled plate, controlling the rolling reduction of each pass to be between 30 and 60 percent, lubricating and cooling by using rolling oil, wherein the proportion of base oil in the rolling oil is not less than 95 percent, and simultaneously adding oily additives (such as organic acid, alcohol, ester and the like) which are not more than 5 percent to ensure that the surface of the plate is smooth and bright, so as to obtain an aluminum foil blank with the thickness of 0.5 mm.

4) Intermediate annealing

And heating the aluminum foil blank to 350 ℃ in a box type annealing furnace, and preserving heat for 6 hours for intermediate annealing so as to completely recrystallize the metal structure.

5) Rolling of aluminium foil

The interannealed 0.5mm thick aluminum foil stock was rolled to 0.07mm in three passes under the following conditions: 0.5mm → 0.3mm → 0.16mm → 0.07mm, the 0.07mm aluminum foil is rolled up and then rolled to the single layer 0.045mm thick aluminum foil; the arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll is controlled step by step in the aluminum foil rolling process and is respectively as follows: 150nm, 100nm and 48 nm. The arithmetic mean deviation Ra of the surface profile of the 0.045mm thick aluminum foil was 56.6 nm.

6) Annealing of aluminum foil finished products

And the box-type furnace finished product annealing of the aluminum foil with the thickness of 0.045mm comprises the steps of keeping at 300 ℃ for 40 hours, discharging and air cooling.

The mechanical properties of the obtained aluminum foil sample with the width of 15mm are detected by an INSTRON aluminum foil tensile tester, the elongation of the aluminum foil sample is detected by a non-contact infrared sensor, the gauge length is 50mm, and the tensile speeds are 1mm/min (before yielding) and 3mm/min (after yielding) respectively. The aluminum foil is detected to have the tensile strength of 82.3MPa and the elongation of 18.1 percent.

Compounding epoxy resin adhesive and nylon, and cutting the aluminum foil into sheet samples, wherein the specific process comprises the following steps:

s1 gluing the surface of the aluminum foil: diluting the epoxy resin adhesive with ethyl acetate, dripping the diluted epoxy resin adhesive on the surface of the aluminum foil, uniformly coating the aluminum foil by using a wire bar coater, and drying the aluminum foil in an oven to remove the ethyl acetate.

S2 aluminum foil-nylon compounding: and (4) compounding the aluminum foil dried in the step (S1) with nylon at 100 ℃ to obtain the aluminum-plastic composite film.

S3 curing: and (5) keeping the aluminum-plastic composite film in the step S2 in an oven at 70 ℃ for 7 days.

And (3) carrying out T-shaped peeling detection on the aged aluminum-plastic film sample according to the GB8808, wherein the peeling strength is detected to be 6.71N/15 mm.

Example 3

The procedure for preparing aluminum foil using the material of example 1 was as follows:

1) homogenization treatment of semicontinuous ingot casting

And (2) sawing and milling a rectangular cast ingot obtained by semi-continuous casting, wherein the sawing amount of two ends of the rectangular cast ingot is not less than 30mm, the other four surfaces of the rectangular cast ingot are two large surfaces and two small surfaces respectively, the two large surfaces and the two small surfaces are milled respectively, uneven microscopic tissue layers on the surface of the cast ingot are removed, and the milling amount of each large surface and each small surface is not less than 15 mm. Then heating the ingot in a box furnace at 600 ℃ for 10h, and then reducing the temperature to the hot rolling temperature for hot rolling the ingot.

2) Hot rolling

And (2) carrying out hot rough rolling and hot finish rolling on the cast ingot by adopting 1+ N (N is more than or equal to 1) hot continuous rolling equipment, controlling the thickness of the plate to be 4.5mm when the rolling is started and the temperature of the plate to be not less than 250 ℃ when the rolling is finished, rolling, and slowly cooling the aluminum coil at room temperature. In order to ensure good lubrication, cooling and surface quality of the plate between a roller and the plate in the hot rolling process, water-based emulsion is adopted for lubrication, and the emulsion is at a temperature of between 45 and 65 ℃ and at a pH value of between 7 and 8 so as to prevent the plate from being corroded.

3) Cold rolling

And (2) cold rolling the hot rolled plate, controlling the rolling reduction of each pass to be between 30 and 60 percent, lubricating and cooling by using rolling oil, wherein the proportion of base oil in the rolling oil is not less than 95 percent, and simultaneously adding oily additives (such as organic acid, alcohol, ester and the like) which are not more than 5 percent to ensure that the surface of the plate is smooth and bright, so as to obtain an aluminum foil blank with the thickness of 0.7 mm.

4) Intermediate annealing

And heating the aluminum foil blank to 360 ℃ in a box type annealing furnace, and preserving heat for 4 hours for intermediate annealing to completely recrystallize the metal structure.

5) Rolling of aluminium foil

The interannealed aluminum foil stock with the thickness of 0.7mm is rolled in the following four passes under the following conditions to prepare an aluminum foil with the thickness of 0.07 mm: 0.7mm → 0.5mm → 0.3mm → 0.16mm → 0.07mm, and the aluminum foil of 0.07mm is rolled up and then laminated to the aluminum foil of 0.035mm in a single layer thickness. The arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll is controlled step by step in the aluminum foil rolling process: 200nm, 130nm and 95 nm. The arithmetic mean deviation Ra of the surface profile of the aluminum foil was obtained to be 110 nm.

6) Annealing of finished aluminum foil

And the box-type furnace finished product annealing of the aluminum foil with the thickness of 0.045mm comprises the steps of keeping at 320 ℃ for 50 hours, discharging and air cooling.

The mechanical properties of the prepared aluminum foil are detected by an INSTRON aluminum foil tensile tester, the elongation of the prepared aluminum foil is detected by adopting a non-contact infrared sensor, the width of an aluminum foil sample is 15mm, the gauge length is 50mm, and the tensile speeds are 1mm/min (before yielding) and 3mm/min (after yielding) respectively. The aluminum foil is detected to have the tensile strength of 83.6MPa and the elongation of 16.5 percent.

Compounding epoxy resin adhesive and nylon, and cutting the aluminum foil into sheet samples, wherein the specific process comprises the following steps:

s1 gluing the surface of the aluminum foil: diluting the epoxy resin adhesive with ethyl acetate, dripping the diluted epoxy resin adhesive on the surface of the aluminum foil, uniformly coating the aluminum foil by using a wire bar coater, and drying the aluminum foil in an oven to remove the ethyl acetate.

S2 aluminum foil-nylon compounding: and (4) compounding the aluminum foil dried in the step S1 with nylon at the temperature of 100 ℃ to obtain the aluminum-plastic composite film.

S3 curing: and (5) keeping the aluminum-plastic composite film in the step S2 at the temperature of 70 ℃ in an oven for 7 days.

And (3) carrying out T-shaped peeling detection on the aged aluminum-plastic film sample according to the GB8808 to obtain the peeling strength of 6.14N/15 mm.

Comparative example 1

The procedure for preparing aluminum foil using the material of example 1 was as follows:

1) homogenization treatment of semicontinuous ingot casting

And (2) sawing and milling a rectangular cast ingot obtained by semi-continuous casting, wherein the sawing amount of two ends of the rectangular cast ingot is not less than 30mm, the other four surfaces of the rectangular cast ingot are two large surfaces and two small surfaces respectively, the two large surfaces and the two small surfaces are milled respectively, uneven microscopic tissue layers on the surface of the cast ingot are removed, and the milling amount of each large surface and each small surface is not less than 15 mm. Then heated in a box furnace at 610 ℃ for 8h, and then cooled to the hot rolling temperature to hot-roll the ingot.

2) Hot rolling

And (2) carrying out hot rough rolling and hot finish rolling on the cast ingot by adopting 1+ N (N is more than or equal to 1) hot continuous rolling equipment, controlling the thickness of the plate to be 4.0mm when the rolling is started and the temperature of the plate to be not less than 250 ℃ when the rolling is finished, rolling, and slowly cooling the aluminum coil at room temperature. In order to ensure good lubrication, cooling and surface quality of the plate between a roller and the plate in the hot rolling process, water-based emulsion is adopted for lubrication, and the emulsion is at a temperature of between 45 and 65 ℃ and at a pH value of between 7 and 8 so as to prevent the plate from being corroded.

3) Cold rolling

And (2) cold rolling the hot rolled plate, controlling the rolling reduction of each pass to be between 30 and 60 percent, lubricating and cooling by using rolling oil, wherein the proportion of base oil in the rolling oil is not less than 95 percent, and simultaneously adding oily additives (such as organic acid, alcohol, ester and the like) which are not more than 5 percent to ensure that the surface of the plate is smooth and bright, so as to obtain an aluminum foil blank with the thickness of 0.8 mm.

4) Intermediate annealing

And heating the aluminum foil blank to 360 ℃ in a box type annealing furnace, and preserving heat for 2 hours for intermediate annealing to completely recrystallize the metal structure.

5) Rolling of aluminium foil

The interannealed aluminum foil blank with the thickness of 0.8mm is rolled in the following four passes under the following conditions to prepare an aluminum foil with the thickness of 0.08 mm: 0.7mm → 0.5mm → 0.3mm → 0.16mm → 0.08mm, and the aluminum foil of 0.08mm is rolled up and then laminated to the aluminum foil of 0.040mm single layer thickness. The arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll is controlled step by step in the aluminum foil rolling process: 300nm, 250nm and 120 nm. The arithmetic mean deviation Ra of the surface profile of the aluminum foil was 150 nm.

6) Annealing of finished aluminum foil

And the box-type furnace finished product annealing of the aluminum foil with the thickness of 0.045mm comprises the steps of keeping the aluminum foil at 220 ℃ for 90 hours, discharging the aluminum foil out of the furnace and air cooling the aluminum foil.

The mechanical properties of the prepared aluminum foil are detected by an INSTRON aluminum foil tensile tester, the elongation of the prepared aluminum foil is detected by adopting a non-contact infrared sensor, the width of an aluminum foil sample is 15mm, the gauge length is 50mm, and the tensile speeds are 1mm/min (before yielding) and 3mm/min (after yielding) respectively. The aluminum foil is detected to have the tensile strength of 90.5MPa and the elongation of 13.6 percent.

Compounding epoxy resin adhesive and nylon, and cutting the aluminum foil into sheet samples, wherein the specific process comprises the following steps:

s1 gluing the surface of the aluminum foil: diluting the epoxy resin adhesive with ethyl acetate, dripping the diluted epoxy resin adhesive on the surface of the aluminum foil, uniformly coating the aluminum foil by using a wire bar coater, and drying the aluminum foil in an oven to remove the ethyl acetate.

S2 aluminum foil-nylon compounding: and (4) compounding the aluminum foil dried in the step S1 with nylon at the temperature of 100 ℃ to obtain the aluminum-plastic composite film.

S3 curing: and (5) keeping the aluminum-plastic composite film in the step S2 at the temperature of 70 ℃ in an oven for 7 days.

And (3) carrying out T-shaped peeling detection on the aged aluminum-plastic film sample according to the GB8808 to obtain the peeling strength of 5.50N/15 mm.

Comparative example 2

The preparation of the aluminum foil using the material of example 1 was as follows:

1) homogenization treatment of semicontinuous ingot casting

And (2) sawing and milling a rectangular cast ingot obtained by semi-continuous casting, wherein the sawing amount of two ends of the rectangular cast ingot is not less than 30mm, the other four surfaces of the rectangular cast ingot are two large surfaces and two small surfaces respectively, the two large surfaces and the two small surfaces are milled respectively, uneven microscopic tissue layers on the surface of the cast ingot are removed, and the milling amount of each large surface and each small surface is not less than 15 mm. Then heating the ingot in a box furnace at 520 ℃ for 12h, and then reducing the temperature to the hot rolling temperature for hot rolling the ingot.

2) Hot rolling

And (2) carrying out hot rough rolling and hot finish rolling on the cast ingot by adopting 1+ N (N is more than or equal to 1) hot continuous rolling equipment, controlling the thickness of the plate to be 3.5mm when the rolling is started and the temperature of the plate to be not less than 250 ℃ when the rolling is finished, rolling, and slowly cooling the aluminum coil at room temperature. In order to ensure good lubrication, cooling and surface quality of the plate between a roller and the plate in the hot rolling process, water-based emulsion is adopted for lubrication, and the emulsion is at a temperature of between 45 and 65 ℃ and at a pH value of between 7 and 8 so as to prevent the plate from being corroded.

3) Cold rolling

And (2) cold rolling the hot rolled plate, controlling the rolling reduction of each pass to be between 30 and 60 percent, lubricating and cooling by using rolling oil, wherein the proportion of base oil in the rolling oil is not less than 95 percent, and simultaneously adding oily additives (such as organic acid, alcohol, ester and the like) which are not more than 5 percent to ensure that the surface of the plate is smooth and bright, so as to obtain an aluminum foil blank with the thickness of 0.5 mm.

4) Intermediate annealing

And heating the aluminum foil blank to 360 ℃ in a box type annealing furnace, and preserving heat for 3 hours for intermediate annealing to completely recrystallize the metal structure.

5) Rolling of aluminium foil

The interannealed aluminum foil stock with the thickness of 0.5mm is rolled in the following three passes under the following conditions to prepare an aluminum foil with the thickness of 0.08 mm: 0.5mm → 0.3mm → 0.16mm → 0.08mm, and the 0.08mm aluminum foil is rolled up and then laminated to a single layer of 0.040mm thick aluminum foil. The arithmetic mean deviation Ra of the axial profiles of the rough rolling working roll, the middle rolling working roll and the finish rolling working roll is controlled step by step in the aluminum foil rolling process: 100nm, 45nm and 15 nm. The arithmetic mean deviation Ra of the surface profile of the aluminum foil was 16.2 nm.

6) Annealing of finished aluminum foil

And (3) carrying out box-type furnace finished product annealing on the aluminum foil with the thickness of 0.04mm, namely keeping the aluminum foil at 380 ℃ for 80 hours, discharging the aluminum foil out of the furnace and air cooling the aluminum foil.

The mechanical properties of the prepared aluminum foil are detected by an INSTRON aluminum foil tensile tester, the elongation of the prepared aluminum foil is detected by adopting a non-contact infrared sensor, the width of an aluminum foil sample is 15mm, the gauge length is 50mm, and the tensile speeds are 1mm/min (before yielding) and 3mm/min (after yielding) respectively. The aluminum foil is detected to have the tensile strength of 71.6MPa and the elongation of 10.0 percent.

Compounding an epoxy resin adhesive and nylon, and cutting the aluminum foil into a sheet sample, wherein the specific process comprises the following steps:

s1 gluing the surface of the aluminum foil: diluting the epoxy resin adhesive with ethyl acetate, dripping the diluted epoxy resin adhesive on the surface of the aluminum foil, uniformly coating the aluminum foil by using a wire bar coater, and drying the aluminum foil in an oven to remove the ethyl acetate.

S2 aluminum foil-nylon compounding: and (4) compounding the aluminum foil dried in the step S1 with nylon at the temperature of 100 ℃ to obtain the aluminum-plastic composite film.

S3 curing: and (5) keeping the aluminum-plastic composite film in the step S2 in an oven at 70 ℃ for 7 days.

The cured aluminum-plastic film sample is subjected to a T-shaped peeling test according to the GB8808, and the peel strength of the aluminum foil is detected to be 5.34N/15 mm.

The properties of the aluminum foil prepared in the above examples are shown in table 1 below.

Table 1 test results of properties of aluminum foil prepared according to the present invention

In table 1, the preparation methods of the aluminum foils and the arithmetic mean deviation of the surface profiles of the aluminum foils in examples 1 to 3 are within the scope of the present invention. Therefore, the peeling strength after the aluminum foil and the nylon are compounded, and the tensile strength and the elongation of the aluminum foil per se meet the requirements of the invention. On the other hand, comparative examples 1 and 2 do not satisfy the scope of the present invention, and therefore lead to the following results:

comparative example 1: because the annealing temperature of the finished product is low, the recrystallization degree is incomplete, the elongation of the aluminum foil is low, and in addition, because the arithmetic mean deviation of the surface profile of the aluminum foil is larger than 150nm, the peeling strength of the aluminum foil and nylon after compounding is reduced, and the compounding performance of the aluminum foil is reduced.

Comparative example 2: the homogenization annealing temperature is too low, the primary crystalline phase of the cast ingot cannot be completely segmented and spheroidized, so that secondary phase particles are coarse, in addition, the annealing temperature of a finished product is too high, the grain size grows up, the strength and the elongation of the aluminum foil are reduced, and the requirements of the invention are not met; the arithmetic mean deviation of the surface profile of the aluminum foil is 16.2nm, which exceeds the range of the invention, so that the peeling strength of the aluminum foil and the nylon after compounding is lower, and the compounding performance of the aluminum foil is reduced.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.