Graphene conductive aluminum foil for flexible cable of drag chain and preparation process of graphene conductive aluminum foil

Abstract

The invention relates to the technical field of flexible cable auxiliary material preparation, in particular to a graphene conductive aluminum foil for a drag chain flexible cable and a preparation process of the graphene conductive aluminum foil. The graphene conductive aluminum foil comprises a matrix shielding layer and a graphene reinforced shielding layer, and the thickness of the graphene reinforced shielding layer is 0.2-1.0 time of the thickness of the matrix shielding layer; the substrate shielding layer is an aluminum foil or an aluminum laminated film flexible polymer resin film; the graphene reinforced shielding layer is prepared by curing hydroxylated graphene modified polyurethane resin; the hydroxylated graphene modified polyurethane is prepared from hydroxylated graphene and NCO (isocyanate) terminated polyurethane resin. The drag chain flexible cable prepared from the graphene conductive aluminum foil provided by the invention is circularly bent for more than or equal to 4 million times under the bending radius of the cable diameter of 7x, and the requirement of a shielding material of the drag chain flexible cable for an industrial robot is met.

Description

Technical Field

[0001] The present application relates to the technical field of flexible cable auxiliary material preparation, and in particular to a graphene conductive aluminum foil for drag chain flexible cables and a preparation process thereof. Background Art

[0002] Drag chain cables are highly flexible cables that can move back and forth with the drag chain and are not easily worn or broken. They are widely used in drag chain systems, electronic information sensing technology, computer systems, measurement and control technology, industrial robots, etc. With the rapid development of industrial robots, higher requirements are placed on the anti-electromagnetic interference performance of drag chain cables. Good shielding materials can ensure the stability of data transmission and protect cables from electromagnetic interference and influence.

[0003] At present, the traditional shielding material used in drag chain flexible cables is usually aluminum foil. The overall anti-electromagnetic interference performance is improved by controlling the number of aluminum foil layers in the drag chain flexible cables. However, the shielding layer formed by multiple layers of aluminum foil will affect the overall toughness and cycle life of the drag chain flexible cables.

[0004] In order to solve the problems of low toughness and cycle life of the above-mentioned traditional shielding materials, scientific researchers have developed a new type of graphene conductive aluminum foil. Only a single layer of graphene conductive aluminum foil can play the anti-electromagnetic interference performance of the shielding layer formed by three layers of aluminum foil. The existing graphene conductive aluminum foil includes aluminum foil and a graphene enhanced shielding layer attached to the surface of the aluminum foil. The graphene enhanced shielding layer is formed by curing graphene slurry. The graphene slurry includes graphene, epoxy resin, dispersant, and leveling agent. The graphene content is 10-30wt%. The reason why epoxy resin is selected as the main binder in the graphene slurry is that epoxy resin forms a good bonding strength with aluminum foil, which can reduce the probability of the graphene enhanced shielding layer detaching from the aluminum foil due to periodic bending.

[0005] With regard to the above-mentioned existing graphene conductive aluminum foil, the inventors found that the brittleness of the graphene-enhanced shielding layer in the existing graphene conductive aluminum foil is relatively large. Under a bending radius of 7x the cable diameter, after 3 million cycles of bending, interlayer peeling occurs between the graphene-enhanced shielding layer and the aluminum foil, and the overall anti-electromagnetic interference performance is significantly reduced. With the rapid development of industrial robots, higher requirements are placed on the cyclic bending life of drag chain cables. Under a bending radius of 7x the cable diameter, the cyclic bending is ≥4 million times, and the existing graphene conductive aluminum foil cannot meet the above requirements. To this end, the inventors provide a graphene conductive aluminum foil for drag chain flexible cables and a preparation process thereof. Summary of the invention

[0006] In order to solve the problem that the existing graphene conductive aluminum foil has a low cyclic bending life and cannot meet the cyclic bending requirements of shielding materials for flexible cables of drag chains for industrial robots, the invention provides a graphene conductive aluminum foil for flexible cables of drag chains and a preparation process thereof. Under a bending radius of 7x the cable diameter, the cyclic bending life is ≥4 million times, which meets the requirements of shielding materials for flexible cables of drag chains for industrial robots.

[0007] The present application provides a graphene conductive aluminum foil for a drag chain flexible cable, which is realized by the following technical solutions:

[0008] A graphene conductive aluminum foil for a drag chain flexible cable is used in the drag chain flexible cable as a shielding material of the drag chain flexible cable. The graphene conductive aluminum foil comprises a base shielding layer and a graphene enhanced shielding layer, the thickness of the graphene enhanced shielding layer is equal to 0.2-1.0 times the thickness of the base shielding layer; the base shielding layer is an aluminum foil or an aluminized flexible polymer resin film; the graphene enhanced shielding layer is prepared by curing a hydroxylated graphene modified polyurethane resin; the hydroxylated graphene modified polyurethane comprises hydroxylated graphene and an NCO-terminated polyurethane resin; the hydroxylated graphene accounts for 10-25wt% of the total mass of the hydroxylated graphene modified polyurethane; the hard segment content in the NCO-terminated polyurethane resin is 28-35wt%, the isocyanate index R value is 1.05-1.15, and the chain extension coefficient f value is 0.87-0.95.

[0009] The flexible cable of the drag chain prepared with the graphene conductive aluminum foil provided in the present invention can be bent cyclically ≥4 million times at a bending radius of 7x the cable diameter, meeting the demand for shielding materials of flexible cables of drag chains for industrial robots. The anti-electromagnetic interference performance of the graphene conductive aluminum foil is also slightly stronger than that of the existing graphene conductive aluminum foil.

[0010] Preferably, when the base shielding layer is aluminum foil with a thickness of 10-25 microns, surface acid etching is required before the hydroxylated graphene-modified polyurethane resin is coated on the surface of the aluminum foil. A groove structure is formed on the surface of the aluminum foil after acid etching, thereby increasing the contact area between the aluminum foil and the graphene-enhanced shielding layer and improving the bonding stability between the graphene-enhanced shielding layer and the base shielding layer.

[0011] Preferably, when the base shielding layer is aluminum foil with a thickness of 10-25 microns, before the hydroxylated graphene-modified polyurethane resin is coated on the surface of the aluminum foil, surface acid etching and low-temperature plasma treatment are required in sequence. The surface of the aluminum foil is subjected to acid etching to form a gully structure, and then the surface of the aluminum foil is subjected to low-temperature plasma treatment to generate active functional groups. The gully structure formed on the surface of the aluminum foil increases the contact area between the aluminum foil and the graphene-enhanced shielding layer. The active functional groups on the surface of the aluminum foil are chemically bonded to the NCO-terminated polyurethane resin in the hydroxylated graphene-modified polyurethane, thereby improving the bonding stability between the graphene-enhanced shielding layer and the base shielding layer.

[0012] Preferably, the aluminum foil comprises an 8-series aluminum alloy and surface-modified graphene, the content of the surface-modified graphene is 0.25-2.0wt%; the surface-modified graphene comprises graphene as a carrier and modified particles loaded on the surface of the graphene, the modified particles are nanoscale aluminum metal clusters and / or single-atom aluminum; the loading rate of modified particles in the surface-modified graphene is ≥4.0wt%.

[0013] By adopting the above technical scheme, the aluminum foil contains surface-modified graphene, and inevitably, the surface-modified graphene is evenly distributed on the surface of the aluminum foil. The surface-modified graphene is activated to form active functional groups, and these active functional groups are chemically bonded to the NCO-terminated polyurethane resin in the hydroxylated graphene-modified polyurethane, which can further improve the bonding stability between the graphene-enhanced shielding layer and the substrate shielding layer.

[0014] Preferably, the aluminum foil is made of 8011 series aluminum alloy and surface-modified graphene, the content of the surface-modified graphene is 0.8-1.2wt%; the surface-modified graphene includes graphene as a carrier and modified particles loaded on the surface of the graphene, the modified particles are monatomic aluminum, and the monatomic aluminum is anchored to defect points on the surface of the graphene; the loading rate of monatomic aluminum in the surface-modified graphene is 5.0wt%.

[0015] By adopting the above technical solution, the bonding stability between the graphene enhanced shielding layer and the substrate shielding layer can be further improved.

[0016] The present application provides a preparation process of graphene conductive aluminum foil for a drag chain flexible cable, which is achieved through the following technical solutions:

[0017] A preparation process of graphene conductive aluminum foil for a drag chain flexible cable comprises the following steps:

[0018] Step 1, preparation of hydroxylated graphene-modified polyurethane;

[0019] Step 2: The surface of the aluminum foil is subjected to surface modification treatment, wherein the surface modification treatment is an acid etching treatment, and the specific operation of the acid etching treatment is as follows: a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is prepared, and the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 1-3 g / m2. After the acid etching treatment for 300-360 seconds, the aluminum foil is rinsed with distilled water for at least three times and dried;

[0020] Alternatively, the surface modification treatment further includes low-temperature plasma treatment, and the specific operation of the low-temperature plasma treatment is as follows: placing the aluminum foil that has been subjected to acid etching treatment in a low-temperature plasma treatment instrument, adjusting the power to 800-1000W, adjusting the gas pressure to 0.20-0.25MPa, using nitrogen as the working gas, and treating for 200-400s. After the low-temperature plasma treatment is completed, rinse with distilled water for at least three times and dry;

[0021] Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum foil that has been surface-modified in step two, place it at 80-120° C. for 2-4 hours, and cool it to room temperature to obtain the graphene conductive aluminum foil for the drag chain flexible cable.

[0022] The preparation process of the invention is relatively simple, has low operation difficulty, and is easy to realize industrial production and manufacturing.

[0023] Preferably, when the base shielding layer is an aluminum-coated flexible polymer resin film, the aluminum-coated flexible polymer resin film includes an aluminum-coated film layer and a flexible polymer resin film, and the flexible polymer resin film is any one of TPU, TPEE, TPV, TPSiV, TPO, TPS, TPAE, PET, SEBS, and EVA; the thickness of the flexible polymer resin film is 50-200 microns; the thickness of the aluminum-coated film layer is 5-20 microns.

[0024] Preferably, the aluminized film flexible polymer resin film is an aluminized TPU film with a Shore hardness of 80-90A, the TPU film thickness is 100±5 microns, and the aluminized film layer thickness is 15-20 microns.

[0025] Preferably, when the base shielding layer is an aluminum-coated flexible polymer resin film, the surface needs to be acid-etched before the hydroxylated graphene-modified polyurethane resin is coated on the aluminum-coated flexible polymer resin film. The surface of the aluminum-coated film forms a gully structure after acid etching. The thickness of the aluminum-coated film layer in the aluminum-coated flexible polymer resin film is 10-20 microns. The gully structure formed on the surface of the aluminum-coated film after acid etching increases the contact area between the aluminum-coated flexible polymer resin film and the graphene enhanced shielding layer, thereby improving the bonding stability between the graphene enhanced shielding layer and the base shielding layer.

[0026] The present application provides a preparation process of graphene conductive aluminum foil for a drag chain flexible cable, which is achieved through the following technical solutions:

[0027] A preparation process of graphene conductive aluminum foil for a drag chain flexible cable comprises the following steps:

[0028] Step 1, preparation of hydroxylated graphene-modified polyurethane;

[0029] Step 2: The surface of the aluminum-plated flexible polymer resin film is subjected to surface modification treatment, wherein the surface modification treatment is an acid etching treatment, and the specific operation of the acid etching treatment is as follows: a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is prepared, and the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is atomized and sprayed on the surface of the aluminum-plated flexible polymer resin film, and the amount of the atomized hydrochloric acid aqueous solution is 1-3 g / m2. After the acid etching treatment for 300-360 seconds, the film is rinsed with distilled water for at least three times and dried;

[0030] Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum-coated flexible polymer resin film that has completed surface modification treatment in step two, place it at 65-95°C for 4-8h, and cool it to room temperature to obtain the graphene conductive aluminum foil for drag chain flexible cables.

[0031] The preparation process of the present invention is relatively simple, the operation difficulty is low, and it is easy to realize industrial production and manufacturing. The flexible cable of the drag chain prepared by using the above-mentioned graphene conductive aluminum foil has better bending resistance and cycle service life while ensuring anti-electromagnetic interference performance, and better meets the demand for shielding materials of flexible cables of drag chains for industrial robots.

[0032] In summary, this application has the following advantages:

[0033] 1. The graphene conductive aluminum foil provided in the present invention has good anti-electromagnetic interference performance. The flexible cable of the drag chain prepared by using the graphene conductive aluminum foil can be bent cyclically ≥4 million times at a bending radius of 7x the cable diameter, meeting the demand for shielding materials of flexible cables of drag chains for industrial robots.

[0034] 2. In the present invention, the surface of the substrate shielding layer is modified to improve the bonding strength and bonding stability between the substrate shielding layer and the graphene enhanced shielding layer. The flexible cable of the drag chain prepared by the graphene conductive aluminum foil in the invention has better anti-bending and cycle service life while ensuring anti-electromagnetic interference performance.

[0035] 3. The preparation process of the present invention is relatively simple, has low operating difficulty, and is easy to implement industrial production. DETAILED DESCRIPTION

[0036] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples and comparative examples.

[0037] Example

[0038] A graphene conductive aluminum foil for a drag chain flexible cable comprises a base shielding layer and a graphene enhanced shielding layer, wherein the thickness of the graphene enhanced shielding layer is equal to 0.2-1.0 times the thickness of the base shielding layer.

[0039] Preferably, the thickness of the graphene enhanced shielding layer is equal to 0.4-0.6 times the thickness of the substrate shielding layer.

[0040] The base shielding layer is an aluminum foil or an aluminum-plated flexible polymer resin film.

[0041] When the substrate shielding layer is aluminum foil, the thickness of the aluminum foil is 10-25 microns. Preferably, when the substrate shielding layer is aluminum foil, the thickness of the aluminum foil is 20-25 microns.

[0042] When the base shielding layer is an aluminized flexible polymer resin film with a thickness of 50-200 microns, the aluminized flexible polymer resin film includes an aluminized film layer and a flexible polymer resin film, and the flexible polymer resin film is any one of TPU, TPEE, TPV, TPSiV, TPO, TPS, TPAE, PET, SEBS, and EVA. The thickness of the aluminized film layer is 5-20 microns.

[0043] Preferably, the aluminized film flexible polymer resin film is an aluminized TPU film with a Shore hardness of 80-90 A. The TPU film thickness is 100±5 microns, and the aluminized film layer thickness is 15-20 microns.

[0044] The graphene-enhanced shielding layer is prepared by curing hydroxylated graphene-modified polyurethane resin.

[0045] The hydroxylated graphene-modified polyurethane is prepared from hydroxylated graphene and NCO-terminated polyurethane resin.

[0046] The hydroxylated graphene accounts for 10-25 wt % of the total mass of the hydroxylated graphene-modified polyurethane. Preferably, the hydroxylated graphene accounts for 22-26 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0047] The hard segment content of the NCO-terminated polyurethane resin is 28-35wt%, the isocyanate index R value is 1.05-1.15, and the chain extension coefficient f value is 0.87-0.95.

[0048] Preferably, the hard segment content in the NCO-terminated polyurethane resin is 30-32 wt %, the isocyanate index R value is 1.08-1.10, and the chain extension coefficient f value*isocyanate index R value=1.

[0049] NCO-terminated polyurethane resins can be custom-made or existing NCO-terminated polyurethane resins can be used.

[0050] When the base shielding layer is aluminum foil with a thickness of 10-25 microns, surface acid etching is required before coating the surface of the aluminum foil with the hydroxylated graphene-modified polyurethane resin. A groove structure is formed on the surface of the aluminum foil after acid etching, thereby increasing the contact area between the aluminum foil and the graphene-enhanced shielding layer and improving the bonding stability between the graphene-enhanced shielding layer and the base shielding layer.

[0051] Furthermore, before the hydroxylated graphene-modified polyurethane resin is coated on the surface of the aluminum foil, it is necessary to perform surface acid etching treatment and low-temperature plasma treatment in sequence. The surface of the aluminum foil is subjected to acid etching to form a gully structure. The surface of the aluminum foil is then subjected to low-temperature plasma treatment to generate active functional groups. The working gas in the low-temperature plasma treatment is at least one of nitrogen, ammonia, oxygen, ozone, and air. The gully structure formed on the surface of the aluminum foil increases the contact area between the aluminum foil and the graphene-enhanced shielding layer. The active functional groups on the surface of the aluminum foil are chemically bonded to the NCO-terminated polyurethane resin in the hydroxylated graphene-modified polyurethane, thereby improving the bonding stability between the graphene-enhanced shielding layer and the substrate shielding layer.

[0052] In order to further improve the bonding stability of the base shielding layer and the graphene-enhanced shielding layer, the inventors have developed a special aluminum foil, specifically, the aluminum foil comprises 8 series aluminum alloy and surface-modified graphene, preferably, the 8 series aluminum alloy is 8011 series aluminum alloy, which can be purchased commercially. The content of the surface-modified graphene is 0.25-2.0wt%, preferably, the content of the surface-modified graphene is 0.8-1.2wt%.

[0053] The surface modified graphene includes graphene as a carrier and modified particles loaded on the surface of the graphene. The modified particles are nano-scale aluminum metal clusters and / or single-atom aluminum. The loading rate of modified particles in the surface modified graphene is ≥4.0wt%. Both the surface modified graphene of nano-aluminum clusters and the surface modified graphene of single-atom aluminum can be customized. Preferably, the modified particles are single-atom aluminum, which is anchored to the defective sites on the graphene surface; the loading rate of single-atom aluminum in the surface modified graphene is 5.0wt%, which is customized by Beijing Graphene Technology Research Institute.

[0054] Based on the base shielding layer being aluminum foil, a preparation process of graphene conductive aluminum foil for drag chain flexible cables comprises the following steps:

[0055] Step 1, preparation of hydroxylated graphene-modified polyurethane;

[0056] Step 2: The surface of the aluminum foil is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: prepare a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L, spray the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L on the surface of the aluminum foil after atomization, the amount of atomized hydrochloric acid aqueous solution is 1-3 g / m2, and after the acid etching treatment for 300-360 seconds, rinse with distilled water for at least three times and dry;

[0057] Alternatively, the surface modification treatment also includes low-temperature plasma treatment. The specific operation of the low-temperature plasma treatment is as follows: the aluminum foil that has been subjected to acid etching is placed in a low-temperature plasma treatment apparatus, the power is adjusted to 800-1000W, the gas pressure is adjusted to 0.20-0.25MPa, the working gas is nitrogen, the treatment time is 200-400s, and after the low-temperature plasma treatment is completed, it is rinsed with distilled water for at least three times and dried;

[0058] Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum foil that has been surface-modified in step two, place it at 80-120° C. for 2-4 hours, and cool it to room temperature to obtain the graphene conductive aluminum foil for the drag chain flexible cable.

[0059] When the base shielding layer is an aluminum-plated flexible polymer resin film, a preparation process of a graphene conductive aluminum foil for a drag chain flexible cable comprises the following steps:

[0060] Step 1, preparation of hydroxylated graphene-modified polyurethane;

[0061] Step 2: The surface of the aluminum-plated flexible polymer resin film is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: prepare a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L, atomize the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L and spray it on the surface of the aluminum-plated flexible polymer resin film, the amount of the atomized hydrochloric acid aqueous solution is 1-3 g / m2, and after the acid etching treatment for 300-360s, rinse with distilled water at least three times and dry;

[0062] Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum-coated flexible polymer resin film that has completed surface modification treatment in step two, place it at 65-95°C for 4-8h, and cool it to room temperature to obtain the graphene conductive aluminum foil for drag chain flexible cables.

[0063] When the base shielding layer is an aluminum-coated flexible polymer resin film, the prepared graphene conductive aluminum foil has excellent low-temperature toughness. Therefore, the flexible cable for the drag chain prepared with the graphene conductive aluminum foil has better bending resistance and cycle service life while ensuring anti-electromagnetic interference performance, and better meets the demand for shielding materials for flexible cables for drag chains used in industrial robots.

[0064] The core creativity of the technical solution of the present invention is highlighted and demonstrated through the following examples and comparative examples.

[0065] Embodiment 1: A graphene conductive aluminum foil for a drag chain flexible cable includes a 15 micron thick aluminum foil and a 10 micron thick graphene reinforced shielding layer. The graphene reinforced shielding layer is prepared by curing a hydroxylated graphene modified polyurethane resin. The hydroxylated graphene modified polyurethane includes hydroxylated graphene and NCO terminated polyurethane resin. Among them, the hydroxylated graphene accounts for 15wt% of the total mass of the hydroxylated graphene modified polyurethane. The hard segment content in the NCO terminated polyurethane resin is 30.3wt%, the isocyanate index R value is 1.08, the isocyanate index R value*chain extension coefficient f value=1, and the chain extension coefficient f value is 1 / 1.08.

[0066] A preparation process of graphene conductive aluminum foil for a drag chain flexible cable comprises the following steps:

[0067] Step 1, preparation of hydroxylated graphene-modified polyurethane:

[0068] S1.1, heat 40 g of polytetrahydrofuran diol PTMEG (PolyTHF 2000 from BASF) and 74 g of polycaprolactone hexamethylene carbonate diol CD2220PL (Dacel Corporation, Japan) to 120°C, vacuum dehydrate for 1 hour, and set aside;

[0069] S1.2, 40 g of polytetrahydrofuran diol PTMEG and 74 g of polycaprolactone hexamethylene carbonate diol CD2220PL which have been vacuum dehydrated in S1.1 are mixed evenly with 15 g of MDI-50, 12.6 g of 4,4'-dicyclohexylmethane diisocyanate HMDI, and 0.08 g of catalyst dibutyltin dilaurate, and the mixture is heated to 85° C. for prepolymerization for 3.0 h, and acetone solvent is added dropwise to adjust the viscosity to 2500 mPa·s, thereby obtaining a polyurethane prepolymer solution;

[0070] S1.3, add 5.08 g of 3-methyl-1,5-pentanediol, 0.04 g of catalyst dibutyltin dilaurate, 2 g of defoamer - silicone defoamer Efka SI 2741, 3 g of leveling agent - DOWSIL 8526, 1.6 g of antioxidant 1010, and 1.4 g of UV324 to the polyurethane prepolymer solution, stir and mix at 240 rpm for 5 min, heat to 95° C. and react for 1.0 h, add acetone solvent dropwise to adjust the viscosity to 2500 mPa·s, and obtain NCO-terminated polyurethane resin;

[0071] S1.4, adjusting the temperature of the NCO-terminated polyurethane resin to 45°C, first dry-kneading 30g of hydroxylated graphene (TNRGOH hydroxylated graphene from Chengdu Organic Chemistry Co., Ltd., Chinese Academy of Sciences, purity>98wt%, thickness 0.55-3.74nm, diameter 0.5-3μm, number of layers<10 layers, oxygen content>10wt%) and 3g of KH570 coupling agent for 5min, adding the resulting mixture to the NCO-terminated polyurethane resin, stirring at 160rpm for 5min, and then dropping acetone solvent to adjust the viscosity to 2500mPa·s, to obtain a hydroxylated graphene-modified polyurethane with a solid content of 42.5%;

[0072] Step 2: The surface of aluminum foil (15 μm thick, Jiangsu Keyao Aluminum Co., Ltd.) was subjected to surface modification treatment, which was acid etching treatment. The specific operation of the acid etching treatment was as follows: a 0.2 mol / L hydrochloric acid aqueous solution was prepared, and the 0.2 mol / L hydrochloric acid aqueous solution was atomized and sprayed on the surface of the aluminum foil. The amount of atomized hydrochloric acid aqueous solution was 2.0 g / m 2 After acid etching for 300s, rinse with distilled water three times and dry;

[0073] Step 3: Apply the hydroxylated graphene-modified polyurethane prepared in step 1 to the surface of the aluminum foil that has been subjected to the acid-etched surface modification treatment in step 2. The amount of hydroxylated graphene-modified polyurethane applied is 1.2 g / dm 2 , placed at 120°C to remove the organic solvent, then transferred to an oven, maintained at 95°C for aging for 3 hours, unpacked and cooled to room temperature, to obtain graphene conductive aluminum foil for drag chain flexible cables.

[0074] The difference between Example 2 and Example 1 is that the hydroxylated graphene accounts for 10 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0075] The preparation methods of hydroxylated graphene-modified polyurethane are as follows: S1.4, adjust the temperature of the NCO-terminated polyurethane resin to 45°C, first dry-knead 18.9 g of hydroxylated graphene and 3 g of KH570 coupling agent for 5 minutes, add the resulting mixture to the NCO-terminated polyurethane resin, stir at 160 rpm for 5 minutes, and then add acetone solvent to adjust the viscosity to 2500 mPa·s.

[0076] The difference between Example 3 and Example 1 is that the hydroxylated graphene accounts for 20 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0077] The preparation methods of hydroxylated graphene-modified polyurethane are as follows: S1.4, adjust the temperature of the NCO-terminated polyurethane resin to 45°C, first dry-knead 42.6 g of hydroxylated graphene and 3 g of KH570 coupling agent for 5 minutes, add the resulting mixture to the NCO-terminated polyurethane resin, stir at 160 rpm for 5 minutes, and then add acetone solvent to adjust the viscosity to 2500 mPa·s.

[0078] The difference between Example 4 and Example 1 is that the hydroxylated graphene accounts for 25 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0079] The preparation methods of hydroxylated graphene-modified polyurethane are as follows: S1.4, adjust the temperature of the NCO-terminated polyurethane resin to 45°C, first dry-knead 56.8 g of hydroxylated graphene and 3 g of KH570 coupling agent for 5 minutes, add the resulting mixture to the NCO-terminated polyurethane resin, stir at 160 rpm for 5 minutes, and then add acetone solvent to adjust the viscosity to 2500 mPa·s.

[0080] The difference between Example 5 and Example 1 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, and the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a 0.1 mol / L hydrochloric acid aqueous solution is prepared, and the 0.1 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0081] The difference between Example 6 and Example 1 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, and the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a 0.3 mol / L hydrochloric acid aqueous solution is prepared, and the 0.3 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After acid etching for 300s, rinse three times with distilled water and dry.

[0082] The difference between Example 7 and Example 1 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: a 0.4 mol / L hydrochloric acid aqueous solution is prepared, and the 0.4 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0083] The difference between Example 8 and Example 1 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, and the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a 0.5 mol / L hydrochloric acid aqueous solution is prepared, and the 0.5 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0084] The difference between Example 9 and Example 1 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, and the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a 0.15 mol / L hydrochloric acid aqueous solution is prepared, and the 0.15 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After 300s of acid etching, the aluminum foil was rinsed three times with distilled water and dried. Then, the aluminum foil was sprayed with a 0.15 mol / L hydrochloric acid aqueous solution. The amount of atomized hydrochloric acid aqueous solution was 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0085] The difference between Example 10 and Example 9 is that: in step 2, the surface of the aluminum foil is subjected to surface modification treatment, and the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a 0.15 mol / L hydrochloric acid aqueous solution is prepared, and the 0.15 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After 300s of acid etching, the aluminum foil was rinsed three times with distilled water and dried. Then, the aluminum foil was sprayed with a 0.15 mol / L hydrochloric acid aqueous solution. The amount of atomized hydrochloric acid aqueous solution was 2.0 g / m 2 After the acid etching treatment for 300s, the aluminum foil is rinsed three times with distilled water and dried. The obtained aluminum foil is subjected to low-temperature plasma treatment. The specific operation of the low-temperature plasma treatment is as follows: the aluminum foil that has completed the acid etching treatment is placed in a low-temperature plasma treatment instrument, the power is adjusted to 800W, the gas pressure is adjusted to 0.20MPa, the working gas is nitrogen, the treatment time is 300s, and after the low-temperature plasma treatment is completed, it is rinsed three times with distilled water and dried. The other steps are the same as those in Example 9.

[0086] The difference between Example 11 and Example 1 is that the aluminum foil is made of 8011 series aluminum alloy and surface-modified graphene, and the content of the surface-modified graphene is 1.0 wt %. The aluminum foil is commissioned to be produced by Jiangsu Keyao Aluminum Co., Ltd., and the obtained aluminum foil has a thickness of 15 microns and a width of 45 cm.

[0087] The surface modified graphene includes graphene as a carrier and modified particles loaded on the graphene surface, wherein the modified particles are single atomic aluminum, and the single atomic aluminum is anchored at the defective points on the graphene surface. The loading rate of single atomic aluminum in the surface modified graphene is 5.0wt%. The surface modified graphene is customized by Beijing Graphene Technology Research Institute.

[0088] The preparation method disclosed by Beijing Graphene Technology Research Institute is as follows: weigh 200 mg of hydroxylated graphene and disperse it in 200 mL of deionized water to obtain a graphene dispersion; weigh 1.2 g of KOH and dissolve it in 200 mL of deionized water to obtain a KOH solution; add the KOH solution dropwise to the graphene dispersion, stir and dry at 80°C to obtain a graphene / KOH dry powder; weigh 1 g of AlCl3 in a crucible, and place 1.4 g of graphene / KOH dry powder in the crucible; place the crucible containing AlCl3 and the crucible containing graphene / KOH dry powder in the upstream and downstream areas of a tube furnace, respectively, and seal the tube furnace; introduce Ar gas into the tube furnace, and Under Ar atmosphere, the upstream temperature zone of the tube furnace is heated from room temperature to 450°C at a heating rate of 10°C / min and kept warm for 1 hour, and at the same time, the downstream temperature zone of the tube furnace is heated to 630°C at a heating rate of 14°C / min and kept warm for 1 hour to obtain a metal single atom-doped graphene precursor; the obtained metal single atom-doped graphene precursor is added to 100 ml of 1 mol / L dilute hydrochloric acid, stirred, vacuum filtered, washed, and dried to obtain surface-modified graphene.

[0089] The difference between Example 12 and Example 10 is that the aluminum foil is replaced by the aluminum foil in Example 11, which is made of 8011 series aluminum alloy and surface-modified graphene, and the content of the surface-modified graphene is 1.0 wt%.

[0090] The difference between Example 13 and Example 1 is that when the base shielding layer is an aluminized TPU film, the aluminized TPU film has a Shore hardness of 85A (made from BASF Elastollan 1185A10), a TPU film thickness of 100 microns, and an aluminized film layer (PVDF method) thickness of 20 microns, which is customized by Hebei Weisai New Materials Technology Co., Ltd.

[0091] A preparation process of graphene conductive aluminum foil for a drag chain flexible cable comprises the following steps:

[0092] Step 1: The preparation method of hydroxylated graphene-modified polyurethane is the same as the preparation method of hydroxylated graphene-modified polyurethane in Example 1;

[0093] Step 2: The surface of the aluminum-plated TPU film is subjected to surface modification treatment. The surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: prepare a 0.15 mol / L hydrochloric acid aqueous solution, atomize the 0.15 mol / L hydrochloric acid aqueous solution and spray it on the surface of the aluminum foil. The amount of the atomized hydrochloric acid aqueous solution is 1.5 g / m 2 After acid etching for 300s, rinse with distilled water three times and dry;

[0094] Step 3: Apply the hydroxylated graphene-modified polyurethane prepared in step 1 to the surface of the aluminum foil that has been subjected to the acid-etched surface modification treatment in step 2. The amount of hydroxylated graphene-modified polyurethane applied is 1.2 g / dm 2 , place it at 75°C to remove the organic solvent for 3 hours, then transfer it to an oven and maintain it at 85°C for aging for 3 hours. Unpack and cool it to room temperature to obtain graphene conductive aluminum foil for drag chain flexible cables.

[0095] The difference between Example 14 and Example 13 is that: Step 2, the surface of the aluminum-plated TPU film is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: a 0.15 mol / L hydrochloric acid aqueous solution is prepared, and the 0.15 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 1.5 g / m 2 After 300s of acid etching, the aluminum foil was rinsed three times with distilled water and dried. Then, the aluminum foil was sprayed with a 0.15 mol / L hydrochloric acid aqueous solution. The amount of atomized hydrochloric acid aqueous solution was 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 13.

[0096] The difference between Comparative Example 1 and Example 1 is that the hydroxylated graphene-modified polyurethane is replaced by a graphene-modified epoxy resin, and the graphene content in the graphene-modified epoxy resin is 15 wt %.

[0097] Specifically, the formula of graphene-modified epoxy resin is as follows: 60g epoxy resin E20, 15g maleic anhydride MA, 5g dicyandiamide, 1g KH570 coupling agent, 15g graphene, 1g antioxidant 1010, 2g defoaming agent BYK-A530, and 1g UV-531.

[0098] The difference between Comparative Example 2 and Example 1 is that the hydroxylated graphene accounts for 8 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0099] The preparation method of hydroxylated graphene modified polyurethane is as follows: S1.4, the temperature of NCO-terminated polyurethane resin is adjusted to 45°C, 14.8g of hydroxylated graphene and 3g of KH570 coupling agent are first dry-kneaded for 5min, the resulting mixture is added to the NCO-terminated polyurethane resin, stirred at 160rpm for 5min, and then acetone solvent is added dropwise to adjust the viscosity to 2500mPa·s. The other steps are the same as those in Example 1.

[0100] The difference between Comparative Example 3 and Example 1 is that the hydroxylated graphene accounts for 28 wt % of the total mass of the hydroxylated graphene-modified polyurethane.

[0101] The preparation method of hydroxylated graphene modified polyurethane is as follows: S1.4, the temperature of NCO-terminated polyurethane resin is adjusted to 45°C, 66.3g of hydroxylated graphene and 3g of KH570 coupling agent are first dry-kneaded for 5min, the resulting mixture is added to the NCO-terminated polyurethane resin, stirred at 160rpm for 5min, and then acetone solvent is added dropwise to adjust the viscosity to 2500mPa·s. The other steps are the same as those in Example 1.

[0102] The difference between Comparative Example 4 and Example 1 is that: Step 2, the surface of the aluminum foil is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: a 0.05 mol / L hydrochloric acid aqueous solution is prepared, and the 0.05 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0103] The difference between Comparative Example 5 and Example 1 is that: Step 2, the surface of the aluminum foil is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: a 0.65 mol / L hydrochloric acid aqueous solution is prepared, and the 0.65 mol / L hydrochloric acid aqueous solution is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 2.0 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0104] The difference between Comparative Example 6 and Example 1 is that: in step 2, the surface of the aluminum foil is not subjected to surface modification treatment, and is simply rinsed three times with distilled water and dried. The other steps are the same as those of Example 1.

[0105] The difference between Comparative Example 7 and Example 13 is that: in step 2, the aluminum-plated TPU film is not subjected to surface modification treatment, and is simply rinsed three times with distilled water and dried. The other steps are the same as those of Example 1.

[0106] The difference between Comparative Example 8 and Example 13 is that: Step 2, the surface of the aluminum-plated TPU film is subjected to surface modification treatment, the surface modification treatment is acid etching treatment, and the specific operation of the acid etching treatment is as follows: a hydrochloric acid aqueous solution with a concentration of 0.02 mol / L is prepared, and the hydrochloric acid aqueous solution with a concentration of 0.02 mol / L is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 1.5 g / m 2 After the acid etching for 300 seconds, the product was rinsed three times with distilled water and dried. The other steps were the same as those in Example 1.

[0107] Performance test: Preparation of the test drag chain flexible cable sample: The drag chain flexible cable sample includes four strands of ultra-fine copper wires, and the diameter of a single strand of ultra-fine copper wire is 1.2mm. The ultra-fine copper wire strands are made of ultra-fine bare copper wires twisted into bundles. The conductor twisting method is ultra-fine copper wire twisting, which meets the VDE 0295, Class 6 standard. The single strand of ultra-fine copper wire is coated with 0.8mm thick PP core wire insulation material. After the four strands of ultra-fine copper wires and two strands of 200D nylon yarn are twisted together, the outer wall is covered with a PUR inner sheath with a thickness of 1mm. The outer wall of the PUR inner sheath is covered with graphene conductive aluminum foil to obtain a semi-finished product. The outer wall of the semi-finished product is then covered with a PUR outer sheath with a thickness of 2mm to obtain a test drag chain flexible cable sample with a diameter of 5.5mm.

[0108] 1. Test method for anti-bending performance: Under a bending radius of 7x cable diameter, the samples were cyclically bent for 2 million times, 3 million times, 4 million times, and 5 million times, and the interlayer structure of the graphene conductive aluminum foil in the drag chain flexible cable samples was observed after cyclic bending for 2 million times, 3 million times, 4 million times, and 5 million times, respectively. When interlayer shedding and peeling problems were observed in the matrix shielding layer and the graphene enhanced shielding layer in the graphene conductive aluminum foil, the cyclic bending experiment was terminated. When cracks and damage were observed in the graphene conductive aluminum foil, the cyclic bending experiment was terminated, and the number of cyclic bendings of the drag chain flexible cable samples (10,000 times) was recorded. The number of drag chain flexible cable samples tested in the same batch was 5. When the number of drag chain flexible cable samples tested was ≥ 4, the drag chain flexible cable samples were considered to have qualified anti-bending performance under the number of cyclic bendings (10,000 times).

[0109] 2. Anti-electromagnetic interference performance test method:

[0110] 2.1 The conductive aluminum foil (25 μm thick) in the control group was made into a drag chain flexible cable sample, the drag chain flexible cable sample was powered on at 36 V, and the electromagnetic field strength of the outer layer of the drag chain flexible cable sample was measured to be H1. Then, the electromagnetic field strength of the outer layer of the drag chain flexible cable sample made of graphene conductive aluminum foil in Examples 1-14 and Comparative Examples 1-8 was tested to be Hn.

[0111] Characterization of anti-magnetic field interference performance: △H(%)=(Hn-H1) / H1.

[0112] 2.2. The conductive aluminum foil (25 μm thick) in the control group was made into a drag chain flexible cable sample, the drag chain flexible cable sample was powered on at 36 V, and the electromagnetic field strength of the outer layer of the drag chain flexible cable sample was measured to be E1. Then, the electromagnetic field strength of the outer layer of the drag chain flexible cable sample made of graphene conductive aluminum foil in Examples 1-14 and Comparative Examples 1-8 was tested to be En.

[0113] Characterization of anti-electric field interference performance: △E(%)=(En-E1) / E1.

[0114] Data analysis

[0115] Table 1: Test parameters of anti-bending performance of towline flexible cable samples made of graphene conductive aluminum foil in Examples 1-14 and Comparative Examples 1-15

[0116]

[0117]

[0118] Table 2: Anti-electromagnetic interference performance test parameter table of the towline flexible cable samples made of graphene conductive aluminum foil in Examples 1-14 and Comparative Examples 1-15

[0119]

[0120]

[0121] It can be seen from Examples 1-14 and Comparative Examples 1-8 and Table 1-2 that the hydroxylated graphene should account for 10-25wt% of the total mass of the hydroxylated graphene-modified polyurethane. Too low an amount added will affect the anti-electromagnetic field shielding performance of the graphene conductive aluminum foil, and too much addition will affect the service life of the drag chain flexible cable.

[0122] Combining Examples 1-14 and Comparative Examples 1-8 and Table 1-2, it can be seen that the groove structure formed on the surface of the aluminum foil after acid etching can improve the bonding stability of the matrix shielding layer and the graphene enhanced shielding layer, which is beneficial to improve the cyclic bending service life of the drag chain flexible cable. The concentration of the hydrochloric acid aqueous solution used in the acid etching treatment needs to be strictly controlled, and the preferred concentration range is 0.1-0.5 mol / L. The hydrochloric acid aqueous solution with too low a concentration will not completely etch the aluminum foil surface, and the bonding stability of the matrix shielding layer and the graphene enhanced shielding layer will still be biased, which cannot meet the requirements of the cyclic bending service life of the drag chain flexible cable; and the hydrochloric acid aqueous solution with too high a concentration will corrode the aluminum foil and destroy the overall anti-electromagnetic field shielding performance of the graphene conductive aluminum foil.

[0123] Combining Examples 1-14 and Comparative Examples 1-8 and Table 1-2, it can be seen that after the surface of the aluminum foil is acid-etched to form a gully structure, the surface of the aluminum foil is treated with low-temperature plasma, and the substrate shielding layer and the graphene enhanced shielding layer have better bonding stability. Subsequently, the limit bending performance of the test drag chain flexible cable samples in Examples 9-10 was measured. The number of cyclic bending cycles of Example 10 can reach 6 million times, while the number of cyclic bending cycles of Example 9 is 5 million times.

[0124] Combining Examples 1-14 and Comparative Examples 1-8 and Table 1-2, it can be seen that the research on special aluminum foil shows that the aluminum foil made of single-atom aluminum-modified graphene has better anti-electromagnetic field shielding performance and the number of cycle bending times can reach 5 million times, which meets the requirements of the cyclic bending service life of the drag chain flexible cable.

[0125] From Examples 1-14 and Comparative Examples 1-8 and Table 1-2, it can be seen that the test drag chain flexible cable samples in Example 10 and Example 12 are subjected to extreme bending performance measurement, and the number of cycle bendings of Example 10 can reach 6 million times, while the number of cycle bendings of Example 12 is 6 million times, and when the number of cycle bendings is 7 million times, two of the five groups of drag chain flexible cable samples reach the requirement of 7 million cycle bendings, while Example 10 does not meet the requirement of 7 million cycle bendings. It can be seen that the combination stability of the matrix shielding layer and the graphene enhanced shielding layer in the graphene conductive aluminum foil of Example 12 is better.

[0126] It can be seen from Example 1 and Example 13 and Table 1-2 that the flexible cable for the drag chain prepared with the graphene conductive aluminum foil in Example 13 has better cyclic bending performance and also has better anti-electromagnetic field shielding performance, meeting the shielding performance requirements of the flexible cable for the drag chain.

[0127] It can be seen from Example 13 and Example 14 and Tables 7-8 that the aluminum-coated TPU film also needs to undergo surface acid etching modification treatment, otherwise it will affect the bonding stability between the aluminum-coated TPU film and the graphene enhanced shielding layer. Based on the aluminum-coated TPU film, the optimal concentration of the acid etching solution is controlled to be 0.1-0.3 mol / L of hydrochloric acid aqueous solution, and a double 0.15 mol / L hydrochloric acid aqueous solution acid etching treatment can also be selected to ensure that the aluminum layer on the aluminum-coated TPU film forms grooves, thereby improving the bonding stability between the aluminum-coated TPU film and the graphene enhanced shielding layer.

[0128] According to different customers' requirements for the flexibility and low-temperature resistance of drag chain flexible cables, choose graphene conductive aluminum foil type I composed of economical aluminum foil / graphene enhanced shielding layer, or graphene conductive aluminum foil type II composed of aluminum-plated TPU film / graphene enhanced shielding layer with good flexibility and low-temperature resistance.

[0129] In summary, the graphene conductive aluminum foil provided in the present invention has excellent anti-electromagnetic interference performance, and the prepared drag chain flexible cable has a cycle bending of ≥4 million times at a bending radius of 7x the cable diameter, which meets the demand for shielding materials for drag chain flexible cables for industrial robots.

[0130] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A graphene conductive aluminum foil for a drag chain flexible cable, characterized in that: The graphene conductive aluminum foil is used in a drag chain flexible cable as a shielding material of the drag chain flexible cable; The graphene conductive aluminum foil comprises a base shielding layer and a graphene enhanced shielding layer, and the thickness of the graphene enhanced shielding layer is equal to 0.2-1.0 times the thickness of the base shielding layer; The base shielding layer is an aluminum foil or an aluminum-plated flexible polymer resin film; The graphene-enhanced shielding layer is prepared by curing hydroxylated graphene-modified polyurethane resin; The hydroxylated graphene-modified polyurethane comprises hydroxylated graphene and NCO-terminated polyurethane resin; The hydroxylated graphene accounts for 10-25wt% of the total mass of the hydroxylated graphene-modified polyurethane; The NCO-terminated polyurethane resin has a hard segment content of 28-35 wt%, an isocyanate index R value of 1.05-1.15, and a chain extension coefficient f value of 0.87-0.

95.

2. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 1, characterized in that: When the base shielding layer is aluminum foil with a thickness of 10-25 microns, surface acid etching is required before coating the surface of the aluminum foil with the hydroxylated graphene-modified polyurethane resin. A groove structure is formed on the surface of the aluminum foil after acid etching, thereby increasing the contact area between the aluminum foil and the graphene-enhanced shielding layer and improving the bonding stability between the graphene-enhanced shielding layer and the base shielding layer.

3. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 2, characterized in that: When the base shielding layer is aluminum foil with a thickness of 10-25 microns, before the hydroxylated graphene-modified polyurethane resin is coated on the surface of the aluminum foil, surface acid etching and low-temperature plasma treatment are required in sequence. The surface of the aluminum foil is subjected to acid etching to form a gully structure, and then the surface of the aluminum foil is subjected to low-temperature plasma treatment to generate active functional groups. The gully structure formed on the surface of the aluminum foil increases the contact area between the aluminum foil and the graphene-enhanced shielding layer. The active functional groups on the surface of the aluminum foil are chemically bonded to the NCO-terminated polyurethane resin in the hydroxylated graphene-modified polyurethane, thereby improving the bonding stability between the graphene-enhanced shielding layer and the base shielding layer.

4. A graphene conductive aluminum foil for a drag chain flexible cable according to claim 1 or 2, characterized in that: The aluminum foil comprises 8 series aluminum alloy and surface modified graphene, wherein the content of the surface modified graphene is 0.25-2.0wt%; the surface modified graphene comprises graphene as a carrier and modified particles loaded on the surface of the graphene, wherein the modified particles are nano-scale aluminum metal clusters and / or single-atom aluminum; and the loading rate of the modified particles in the surface modified graphene is ≥4.0wt%.

5. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 4, characterized in that: The aluminum foil includes 8011 series aluminum alloy and surface modified graphene, the content of the surface modified graphene is 0.8-1.2wt%; the surface modified graphene includes graphene as a carrier and modified particles loaded on the surface of the graphene, the modified particles are monatomic aluminum, and the monatomic aluminum is anchored to the defective points on the surface of the graphene; the loading rate of the monatomic aluminum in the surface modified graphene is 5.0wt%.

6. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 1, characterized in that: When the base shielding layer is an aluminum-plated flexible polymer resin film, the aluminum-plated flexible polymer resin film includes an aluminum-plated film layer and a flexible polymer resin film, and the flexible polymer resin film is any one of TPU, TPEE, TPV, TPSiV, TPO, TPS, TPAE, PET, SEBS, and EVA; the thickness of the flexible polymer resin film is 50-200 microns; the thickness of the aluminum-plated film layer is 5-20 microns.

7. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 6, characterized in that: When the base shielding layer is an aluminum-coated flexible polymer resin film, surface acid etching treatment is required before the hydroxylated graphene-modified polyurethane resin is coated on the aluminum-coated flexible polymer resin film. The surface of the aluminum-coated film forms a gully structure after acid etching. The thickness of the aluminum-coated film layer in the aluminum-coated flexible polymer resin film is 10-20 microns. The gully structure formed on the surface of the aluminum-coated film after acid etching increases the contact area between the aluminum-coated flexible polymer resin film and the graphene enhanced shielding layer, thereby improving the bonding stability between the graphene enhanced shielding layer and the base shielding layer.

8. The graphene conductive aluminum foil for a drag chain flexible cable according to claim 6 or 7, characterized in that: The aluminized film flexible polymer resin film is an aluminized TPU film with a Shore hardness of 80-90A, the TPU film thickness is 100±5 microns, and the aluminized film layer thickness is 15-20 microns.

9. A process for preparing the graphene conductive aluminum foil for a drag chain flexible cable according to claim 5, characterized in that: The following steps are involved: Step 1, preparation of hydroxylated graphene-modified polyurethane; Step 2: The surface of the aluminum foil is subjected to surface modification treatment, wherein the surface modification treatment is acid etching treatment. The specific operation of the acid etching treatment is as follows: a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is prepared, and the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L is atomized and sprayed on the surface of the aluminum foil, and the amount of the atomized hydrochloric acid aqueous solution is 1-3 g / m 2 , after acid etching for 300-360s, rinse with distilled water at least three times and dry; Alternatively, the surface modification treatment further includes low-temperature plasma treatment, and the specific operation of the low-temperature plasma treatment is as follows: placing the aluminum foil that has been subjected to acid etching treatment in a low-temperature plasma treatment instrument, adjusting the power to 800-1000W, adjusting the gas pressure to 0.20-0.25MPa, using nitrogen as the working gas, and treating for 200-400s. After the low-temperature plasma treatment is completed, rinse with distilled water for at least three times and dry; Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum foil that has been surface-modified in step two, place it at 80-120° C. for 2-4 hours, and cool it to room temperature to obtain the graphene conductive aluminum foil for the drag chain flexible cable.

10. A process for preparing the graphene conductive aluminum foil for a drag chain flexible cable according to claim 8, characterized in that: The following steps are involved: Step 1, preparation of hydroxylated graphene-modified polyurethane; Step 2: The surface of the aluminum-plated flexible polymer resin film is subjected to surface modification treatment, wherein the surface modification treatment is an acid etching treatment, wherein the specific operation of the acid etching treatment is as follows: preparing a hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L, atomizing the hydrochloric acid aqueous solution with a concentration of 0.1-0.5 mol / L and spraying it on the surface of the aluminum-plated flexible polymer resin film, wherein the amount of the atomized hydrochloric acid aqueous solution is 1-3 g / m 2 , after acid etching for 300-360s, rinse with distilled water at least three times and dry; Step three, apply the hydroxylated graphene-modified polyurethane prepared in step one on the surface of the aluminum-coated flexible polymer resin film that has completed surface modification treatment in step two, place it at 65-95°C for 4-8h, and cool it to room temperature to obtain the graphene conductive aluminum foil for drag chain flexible cables.

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