Modified chlorinated polyolefin as well as preparation method and application thereof

Abstract

The invention relates to modified chlorinated polyolefin as well as a preparation method and application thereof. The modified chlorinated polyolefin is obtained by carrying out alkylation reaction on chlorinated polyolefin and first amine and then acidifying, or carrying out quaternization reaction on chlorinated polyolefin and second amine. The metal layer of the composite current collector prepared by using the modified chlorinated polyolefin as the binder has good adhesive force, and the composite current collector is resistant to electrolyte soaking and high in elongation at break and tensile strength.

Description

Technical Field

[0001] This invention relates to the field of metallization technology for non-metallic materials, and more specifically, to a modified chlorinated polyolefin, its preparation method, and its application. Background Technology

[0002] Current collector composite copper foil is typically composed of two metal layers (such as copper) and a polymer base film (such as PET). The manufacturing process for composite copper foil usually involves a two-step method, including magnetron sputtering and electroplating. Magnetron sputtering forms a copper sputtered layer, but it can easily result in uneven copper film deposition on the base film surface. Furthermore, magnetron sputtering equipment is difficult to operate and expensive. This process is typically designed for composite copper foil with a PET base film; however, when applied to composite copper foil using polypropylene (PP) film as the base film, the lack of reactive groups in PP leads to poor adhesion between the sputtered layer and the base film, making it difficult to meet product requirements.

[0003] To overcome the high cost of magnetron sputtering equipment, electroless copper plating has been developed as an alternative. Electroless copper plating involves adsorbing catalytically active colloidal or nanoparticles, such as palladium, onto the surface of a base film through self-assembly or ion exchange, followed by electroless plating to form copper. To ensure adhesion between the base film and the metal coating, chromic anhydride is typically used to roughen the base film through oxidation, increasing the wettability between the aqueous solution and the substrate in subsequent surface treatments. However, the chromic anhydride process uses highly toxic hexavalent chromium and sulfuric acid, generating large amounts of waste acid and acid mist, and requiring large quantities of pure water, posing significant environmental concerns. Furthermore, oxidation roughening negatively impacts the elongation at break and tensile strength of the composite copper foil, potentially leading to breakage during subsequent carbon coating.

[0004] Furthermore, as the negative electrode current collector in a battery, the composite copper foil comes into contact with the electrolyte during use. Prolonged contact with the electrolyte in existing composite copper foil can easily cause the copper layer to peel off, directly affecting battery life. Summary of the Invention

[0005] The primary objective of this invention is to overcome the aforementioned existing technical problems and provide a modified chlorinated polyolefin.

[0006] A further object of the present invention is to provide a method for preparing the above-mentioned modified chlorinated polyolefin.

[0007] A further object of the present invention is to provide an adhesive composition.

[0008] A further object of the present invention is to provide the application of the above-described adhesive composition in the preparation of composite current collectors.

[0009] A further objective of this invention is to provide a composite current collector.

[0010] A further object of the present invention is to provide a method for preparing the above-mentioned composite current collector.

[0011] The above-mentioned objective of the present invention is achieved through the following technical solution: A modified chlorinated polyolefin is obtained by first alkylating a chlorinated polyolefin with a first amine and then acidifying it, or by quaternizing a chlorinated polyolefin with a second amine. The first amine is a primary amine and / or a secondary amine; the second amine is a tertiary amine.

[0012] The modified chlorinated polyolefin of the present invention has good adhesion to the base film of the composite current collector. On the other hand, the modified chlorinated polyolefin obtained after modification has a positively charged structure (ammonium salt structure or quaternary ammonium cation structure), which can adsorb and penetrate the negatively charged colloidal palladium during the activation process of the chemical copper plating method of the composite current collector into the adhesive layer formed by the modified chlorinated polyolefin. This allows palladium-catalyzed chemical copper to grow from the inside of the adhesive layer, and the formed copper layer is tightly bonded to the adhesive layer, thereby giving the metal layer of the composite current collector good adhesion.

[0013] In addition, the composite current collector made by using the modified chlorinated polyolefin as a binder has good elongation at break and tensile strength, and the copper layer does not fall off after being immersed in electrolyte, showing good resistance to electrolyte immersion.

[0014] The modified chlorinated polyolefin of the present invention is used as a binder in the preparation of composite current collectors, eliminating the need for magnetron sputtering and avoiding the oxidation roughening operation in the chemical copper plating method, effectively solving the environmental problems caused by the use of toxic and harmful reagents in oxidation roughening.

[0015] In this invention, during the quaternization reaction, the second amine acts as a nucleophile to attack the carbon atom in the chlorinated polyolefin that is bonded to the chlorine atom.

[0016] In this invention, the chlorinated polyolefin (before modification) is commonly used as an adhesive, and the coating liquid made from it is viscous after coating and drying.

[0017] Preferably, the chlorine content of the chlorinated polyolefin is 20-70%, specifically 20%, 30%, 40%, 50%, 60% or 70%.

[0018] Preferably, the chlorinated polyolefin in the modified chlorinated polyolefin is at least one of chlorinated polypropylene (such as M-28P from Toyobo, Japan) or chlorinated polyethylene (such as HCPE-40H from Shandong Ketian Chemical Co., Ltd.).

[0019] More preferably, the chlorinated polypropylene has a chlorine content of 20-30 wt%; and the chlorinated polyethylene has a chlorine content of 60-70 wt%.

[0020] Preferably, the first amine is a monoamine.

[0021] More preferably, the structural formula of the first amine is as follows:

[0022] R1, R2, and R3 are each independently selected from hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are substituted or unsubstituted by one or more heteroatoms selected from nitrogen, oxygen, and sulfur; and at least one of R1, R2, and R3 is not H.

[0023] More preferably, the first amine is at least one selected from diethylamine, dipropylamine, dibutylamine, diethanolamine, propylamine, and butylamine.

[0024] Preferably, the second amine is a monoamine.

[0025] More preferably, the structural formula of the second amine is as follows:

[0026] R4, R5 and R6 are each independently selected from substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are replaced or not replaced by one or more heteroatoms of nitrogen, oxygen and sulfur.

[0027] More preferably, the second amine is at least one of triethylamine, tripropylamine, and tributylamine.

[0028] Preferably, the chlorinated polyolefin is first alkylated with a first amine, and then acidified to obtain the composite current collector; the chlorinated polyolefin is chlorinated polypropylene, and the first amine is dibutylamine. Using this method, the resulting composite current collector exhibits better performance.

[0029] The preparation method of the above-mentioned modified chlorinated polyolefin includes the following steps: The chlorinated polyolefin is first alkylated with a first amine, and then acidified to obtain the modified chlorinated polyolefin. Alternatively, the chlorinated polyolefin undergoes a quaternization reaction with the second amine to obtain the modified chlorinated polyolefin.

[0030] Preferably, the chlorine content of the chlorinated polyolefin is 20-70 wt%, specifically 20%, 30%, 40%, 50%, 60% or 70%.

[0031] Preferably, the chlorinated polyolefin in the modified chlorinated polyolefin is at least one of chlorinated polypropylene (such as M-28P from Toyobo, Japan) or chlorinated polyethylene (such as HCPE-40H from Shandong Ketian Chemical Co., Ltd.).

[0032] More preferably, the chlorinated polypropylene has a chlorine content of 20-30 wt%; and the chlorinated polyethylene has a chlorine content of 60-70 wt%.

[0033] Preferably, the first amine is a monoamine.

[0034] More preferably, the structural formula of the first amine is as follows:

[0035] R1, R2, and R3 are each independently selected from hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are substituted or unsubstituted by one or more heteroatoms selected from nitrogen, oxygen, and sulfur; and at least one of R1, R2, and R3 is not H.

[0036] More preferably, the first amine is at least one selected from diethylamine, dipropylamine, dibutylamine, diethanolamine, propylamine, and butylamine.

[0037] Preferably, the molar ratio of chlorine to the first amine in the chlorinated polyolefin is 1:(1.5~6), such as 1:1.5, 1:2, 1:3, 1:4, 1:5, or 1:6.

[0038] Preferably, the alkylation reaction is carried out in the presence of an acid-binding agent.

[0039] More preferably, the molar ratio of the acid-binding agent to the first amine is 1:(1~4), such as 1:1, 1:2, 1:3, or 1:4.

[0040] More preferably, the acid-binding agent includes, but is not limited to, at least one of sodium hydroxide, barium hydroxide, lithium hydroxide, ammonium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, cesium carbonate, sodium methoxide, sodium ethoxide, sodium isopropoxide, ammonia, ethylenediamine, tertiary amine, and magnesium oxide.

[0041] Preferably, the alkylation reaction is carried out in the presence of a solvent; the solvent includes, but is not limited to, at least one of benzene, toluene, xylene, dichloroethane, dichloromethane, chloroform, tetrahydrofuran, acetone, butanone, and acetonitrile.

[0042] More preferably, the ratio of the chlorinated polyolefin to the solvent is 1 g: (4~8) mL.

[0043] Preferably, the alkylation reaction is carried out at a temperature of 60-80°C for 3-5 hours.

[0044] The purpose of acidification is to further form an ammonium salt structure from the amine structure formed after the alkylation reaction.

[0045] Preferably, the molar ratio of the acidified acid to the first amine is (1.0~1.2):1.

[0046] Preferably, the acid used in the acidification includes, but is not limited to, hydrochloric acid.

[0047] Preferably, the acidification temperature is 60~80℃ and the time is 1~3 hours.

[0048] Preferably, the acidification process further includes purification and drying steps.

[0049] More preferably, the purification process is as follows: pour anhydrous ethanol into the reaction system, wash, filter, wash with water, and filter again.

[0050] More preferably, the drying temperature is 50~100°C and the time is 6~10 hours.

[0051] Preferably, the second amine is a monoamine.

[0052] More preferably, the structural formula of the second amine is as follows:

[0053] R4, R5 and R6 are each independently selected from substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are replaced or not replaced by one or more heteroatoms of nitrogen, oxygen and sulfur.

[0054] More preferably, the second amine is at least one of triethylamine, tripropylamine, and tributylamine.

[0055] Preferably, the molar ratio of chlorine to the second amine in the chlorinated polyolefin is 1:(1.5~6), such as 1:1.5, 1:2, 1:3, 1:4, 1:5, or 1:6.

[0056] Preferably, the quaternization reaction is carried out in the presence of a solvent; the solvent includes, but is not limited to, at least one of benzene, toluene, xylene, dichloroethane, dichloromethane, chloroform, tetrahydrofuran, acetone, butanone, and acetonitrile.

[0057] More preferably, the ratio of the chlorinated polyolefin to the solvent is 1 g: (4~8) mL.

[0058] Preferably, the quaternization reaction is carried out at a temperature of 60-80°C for 3-5 hours.

[0059] Preferably, the quaternization reaction is followed by purification and drying steps.

[0060] More preferably, the purification process is as follows: pour anhydrous ethanol into the reaction system, wash, filter, wash with water, and filter again.

[0061] More preferably, the drying temperature is 50~100°C and the time is 6~10 hours.

[0062] An adhesive composition comprising the following components by weight percentage: The above-mentioned modified chlorinated polyolefins are 5-20%. Solvent balance.

[0063] Preferably, the adhesive composition further includes 0.01-0.2% tackifier and 0.1-2% curing agent.

[0064] More preferably, the tackifier is at least one of rosin, terpene resin, petroleum resin, alkylphenol resin, poly-α-methylstyrene resin, ketone-aldehyde resin, xylene-formaldehyde resin, cashew oil-modified phenolic resin, tall oil-modified phenolic resin, natural rubber, polybutene, polyisobutylene, and terpene-phenolic resin emulsion.

[0065] More preferably, the curing agent is at least one of phenolic amine epoxy curing agents (such as T31), polyisocyanate curing agents (such as Bayer N3800), acrylate curing agents (such as R2211), and glycidyl ether curing agents.

[0066] Preferably, the solvent is at least one selected from xylene, dichloromethane, chloroform, methyl ethyl ketone, acetonitrile, acetone, 1,4-dioxane, butanone, isobutyl ketone, ethyl acetate, butyl acetate, tetrahydrofuran, and n-butanol.

[0067] The application of the above-mentioned adhesive composition in the preparation of composite current collectors is also within the scope of protection of this invention.

[0068] A composite current collector includes a polymer substrate layer, an adhesive layer, and a metal layer; the adhesive layer is obtained by curing the above-mentioned adhesive composition.

[0069] Preferably, the polymer substrate layer is made of polypropylene (PP), liquid crystal polymer (LCP), polyethylene terephthalate (PET), or polyimide (PI).

[0070] Since the adhesive layer formed after curing the adhesive composition of the present invention is used as the adhesive layer of the composite current collector, the material of the polymer substrate layer of the composite current collector can be selected not only from liquid crystal polymers, polyethylene terephthalate and polyimide, but also from polypropylene, resulting in good adhesion of the metal layer of the composite current collector.

[0071] Preferably, the metal layer is made of copper.

[0072] The preparation method of the above-mentioned composite current collector includes the following steps: The above-mentioned adhesive composition is coated on the surface of a polymer substrate, cured, activated, debonded, and then subjected to chemical plating and electroplating to obtain the composite current collector.

[0073] Preferably, the coating thickness of the adhesive combination is 0.08~0.15 micrometers.

[0074] Preferably, the curing temperature is 80~120℃ and the time is 0.5~2min.

[0075] Preferably, the process after curing and before activation further includes a pre-impregnation step. The purpose of pre-impregnation is to protect the palladium in the subsequent activation process and reduce contamination from impurities.

[0076] More preferably, the prepreg solution is typically a mixed solution of hydrochloric acid and sodium chloride; it can be prepared from Sanfu SF-H04A and hydrochloric acid.

[0077] Preferably, the activation solution is a mixed solution of palladium chloride, stannous chloride and hydrochloric acid, which can be prepared from Sanfu SF-H04A, Sanfu SF-H05A and hydrochloric acid.

[0078] The purpose of activation is to enable the adhesive layer formed by the adhesive composition to adsorb colloidal palladium, which acts as a catalyst for subsequent electroless plating.

[0079] More preferably, the palladium content in the activation solution is 1~50 ppm, more preferably 1~3 ppm.

[0080] In conventional electroless copper plating processes, the palladium content in the activation solution needs to reach at least 20 ppm to effectively catalyze copper formation during electroless plating and ensure adhesion between the polymer substrate layer and the metal layer. Using the binder composition made from the modified chlorinated polyolefin of this invention as the adhesive layer, the palladium content in the activation solution can be controlled within the conventional range or at a low level. Even with a significantly reduced palladium content in the activation solution, it can still effectively catalyze copper formation during electroless plating and ensure adhesion of the metal layer of the composite current collector, achieving low-palladium electroless copper plating and significantly reducing production costs for enterprises.

[0081] Preferably, the degumming solution is at least one of hydrochloric acid, sodium hypophosphite, and sulfuric acid, and can be prepared from Sanfu SF-H06A.

[0082] The purpose of degelatination is to remove the Sn layer on the outer layer of colloidal palladium. 4+ The outer shell exposes the Pd metal, which is beneficial for subsequent electroless plating.

[0083] Preferably, the electroless plating solution contains copper salt, complexing agent, pH adjuster and stabilizer.

[0084] More preferably, the copper salt includes at least one of copper sulfate, copper chloride, copper nitrate, or copper acetate. More preferably, the complexing agent includes at least one of tartaric acid, tartrate, EDTA, or EDTP. More preferably, the pH adjuster includes at least one of sodium hydroxide, potassium hydroxide, or sulfuric acid. More preferably, the stabilizer includes at least one of cyanide, bipyridine, or PEG1000.

[0085] More preferably, the electroless plating solution can be prepared from Sanfu SF-H700A, Sanfu SF-H700B and Sanfu SF-H700C.

[0086] Preferably, the electroplating solution is a mixed solution of sulfuric acid, copper sulfate and chloride ions, which can be prepared from Sanfu SF-99310A, Sanfu SF-99310B and Sanfu SF-99310C.

[0087] Preferably, the electroplating process further includes an antioxidant treatment step.

[0088] More preferably, the antioxidant solution for the antioxidant treatment contains at least one of citric acid, phosphoric acid, or gluconic acid; the antioxidant solution can be prepared from Sanfu SF-H10A and Sanfu SF-H10B.

[0089] Compared with the prior art, the beneficial effects of the present invention are: (1) The modified chlorinated polyolefin of the present invention has good adhesion to the base film of the composite current collector. On the other hand, the modified chlorinated polyolefin obtained after modification has an ammonium salt structure or a quaternary ammonium cation structure and is positively charged. It can adsorb and penetrate into the adhesive layer formed by the modified chlorinated polyolefin during the activation process of the chemical copper plating method of the composite current collector. This allows the palladium-catalyzed chemical copper to grow out from the inside of the adhesive layer, and the formed copper layer is closely attached to the adhesive layer, thereby giving the metal layer of the composite current collector good adhesion.

[0090] (2) In addition, the composite current collector made by using the modified chlorinated polyolefin as a binder has good elongation at break and tensile strength, and the copper layer does not fall off after being immersed in electrolyte, and has good resistance to immersion in electrolyte.

[0091] (3) The modified chlorinated polyolefin of the present invention is used as a binder in the preparation of composite current collectors, which can eliminate the oxidation roughening operation in the chemical copper plating method and effectively solve the environmental problems caused by the use of toxic and harmful reagents in oxidation roughening. Attached Figure Description

[0092] Figure 1 This is a schematic diagram of the sample to be tested for adhesion testing, which is used for performance testing. Detailed Implementation

[0093] To more clearly and completely describe the technical solution of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention. Various changes can be made within the scope of the claims of the present invention.

[0094] Example 1 This embodiment provides a modified chlorinated polyolefin, the preparation method of which includes the following steps: 20.1 g of chlorinated polypropylene (Toyobo M-28P, Japan) with a chlorine content of 20% was dissolved in 100 mL of tetrahydrofuran. 41.5 g of potassium carbonate and 77.6 g of di-n-butylamine were added, and the mixture was refluxed at 66 °C for 4 hours. Then, 60 mL of 10M hydrochloric acid was gradually added dropwise, and the mixture was stirred at 66 °C for another 2 hours. After the reaction was complete, the product was poured into 500 mL of ethanol, washed repeatedly, filtered, washed with water, filtered again, and the product was vacuum dried at 60 °C for 8 hours to obtain the modified chlorinated polyolefin, denoted as modified chlorinated polyolefin 1#. The structure of modified chlorinated polyolefin 1# is shown below: .

[0095] Example 2 This embodiment provides a modified chlorinated polyolefin, the preparation method of which includes the following steps: 20.1 g of chlorinated polypropylene (Toyobo M-28P, Japan) with a chlorine content of 20% was dissolved in 100 mL of tetrahydrofuran. 60.71 g of triethylamine was added, and the mixture was refluxed at 66 °C for 4 hours. After the reaction, the product was poured into 500 mL of ethanol, washed repeatedly, filtered, washed with water, filtered again, and dried under vacuum at 60 °C for 8 hours to obtain the modified chlorinated polyolefin, denoted as modified chlorinated polyolefin 2#. The structure of modified chlorinated polyolefin 2# is shown below:

[0096] Example 3 This embodiment provides a modified chlorinated polyolefin, the preparation method of which includes the following steps: 20.1 g of chlorinated polypropylene (Toyobo M-28P, Japan) with a chlorine content of 20% was dissolved in 100 mL of tetrahydrofuran. 41.5 g of potassium carbonate and 63.1 g of diethanolamine were added, and the mixture was refluxed at 66 °C for 4 hours. Then, 60 mL of 10M hydrochloric acid was gradually added dropwise, and the mixture was stirred at 66 °C for another 2 hours. After the reaction was complete, the product was poured into 500 mL of ethanol, washed repeatedly, filtered, washed with water, filtered again, and the product was vacuum dried at 60 °C for 8 hours to obtain the modified chlorinated polyolefin, denoted as modified chlorinated polyolefin 3#. The structure of modified chlorinated polyolefin 3# is shown below: .

[0097] Example 4 This embodiment provides a modified chlorinated polyolefin, the preparation method of which includes the following steps: 20.1 g of chlorinated polyethylene (HCPE-40H from Shandong Ketian Chemical Co., Ltd.) with a chlorine content of 67% was dissolved in 100 mL of tetrahydrofuran. 41.5 g of potassium carbonate and 77.6 g of di-n-butylamine were added, and the mixture was refluxed at 66 °C for 4 hours. Then, 60 mL of 10M hydrochloric acid was gradually added dropwise, and the mixture was stirred at 66 °C for another 2 hours. After the reaction was complete, the product was poured into 500 mL of ethanol, washed repeatedly, filtered, washed with water, filtered again, and the product was vacuum dried at 60 °C for 8 hours to obtain the modified chlorinated polyolefin, denoted as modified chlorinated polyolefin 4#. The structure of modified chlorinated polyolefin 4# is shown below: .

[0098] Examples 5-10 Examples 5-10 provide a series of adhesive compositions, the formulations of which are shown in Table 1 below.

[0099] Table 1 (Unit: mass percentage)

[0100] Comparative Example 1 This comparative example provides an adhesive composition that differs from Example 5 in that the modified chlorinated polyolefin 1# of Example 5 is replaced with chlorinated polypropylene (Toyobo M-28P, Japan).

[0101] The preparation methods of the adhesive compositions of Examples 5-10 and Comparative Example 1 include the following steps: mixing each component evenly according to the formula to obtain the adhesive composition.

[0102] Performance testing The adhesive compositions from Examples 5-10 and Comparative Example 1 were used to prepare composite current collectors. The specific preparation process of the composite current collectors is as follows: (1) Coating: A 0.1 μm thick adhesive composition is applied to both sides of a polypropylene film (4.5 μm thick) by roller coating to obtain a coated base film; (2) Curing: The base film coated in step (1) is transferred to a 100℃ hot air oven to dry and cure for 1 min to obtain a cured base film; (3) Pre-impregnation: The cured base film from step (2) is transferred to the pre-impregnation solution and immersed for 30 seconds to obtain the pre-impregnation base film; the pre-impregnation solution is prepared using SF-H04A and 37% hydrochloric acid from Guangzhou Sanfu New Material Technology Co., Ltd. as raw materials, and the opening volume is 150g / L and 50ml / L respectively. (4) Activation: The pre-impregnated base film from step (3) is transferred to the activation solution and immersed for 60 seconds to obtain the activated base film; the palladium ion content in the activation solution is 40 ppm. The activation solution is prepared using palladium chloride, SF-H04A and SF-H05A produced by Guangzhou Sanfu New Material Technology Co., Ltd., and 37% hydrochloric acid as raw materials. Among them, SF-H04A, SF-H05A, and 37% hydrochloric acid produced by Guangzhou Sanfu New Material Technology Co., Ltd. are prepared at a rate of 150 g / L, 5 ml / L, and 50 ml / L respectively. (5) Debonding: The activated base film from step (4) is immersed in a debonding solution at 40°C for 30 seconds to obtain a debonded base film; the debonding solution is prepared using SF-H06A produced by Guangzhou Sanfu New Material Technology Co., Ltd. as raw material, with a start-up volume of 100ml / L. (6) Chemical copper plating: After cleaning the desorbed base film from step (5) with deionized water, it is immersed in a chemical copper plating solution at 40°C for 90 seconds to deposit a chemical copper thickness of 0.05 μm, thus obtaining a chemical copper base film; the chemical copper plating solution is prepared using SF-H700A, SF-H700B, and SF-H700C produced by Guangzhou Sanfu New Material Technology Co., Ltd. as raw materials, with a start-up volume of 100 ml / L for each. (7) Copper plating: After the chemical copper base film in step (6) is cleaned with deionized water, it is transferred to a copper plating solution at 30°C for copper plating to form a copper layer with a thickness (single side) of 1μm, and a copper-coated film is obtained; the copper plating solution is prepared by Guangzhou Sanfu New Material Technology Co., Ltd. using SF-99310A, SF-99310B and SF-99310C with a tank opening volume of 10ml / L, 5ml / L and 5ml / L respectively. (8) Antioxidation: After cleaning the copper-clad film from step (7) with deionized water, it is transferred to an anti-corrosion solution at 30°C for 0.1ASD electropassivation for 20s, then cleaned with deionized water and dried with hot air to obtain the composite current collector. The anti-corrosion solution is prepared using SF-H10A and SF-H10B from Guangzhou Sanfu New Material Technology Co., Ltd. as raw materials, with a tank opening volume of 50ml / L and 10ml / L respectively.

[0103] The composite current collector prepared above was tested according to the following method: (1) Adhesion: The composite current collector is cut into pieces with a length of 200mm × width of 40mm. Then, about two-thirds of one side is hot-pressed with a Hull groove specimen using hot melt adhesive to obtain the test sample. Figure 1 As shown; the lower clamp of the universal testing machine (Dongguan Lixian Instrument Technology Co., Ltd., model: HZ-1004B) clamps one end of the Hull groove specimen of the sample to be tested. Figure 1 The end indicated by the red arrow in the middle), the upper clamp clamps one end of the composite current collector of the sample to be tested ( Figure 1(The blue arrow points to the end), and then the test begins. When the displacement of the sample reaches 30mm, the test is stopped. The average force (N) is calculated by the maximum and minimum forces during the test. The adhesion is expressed as follows: average force (N) / width of composite current collector (cm). The larger the value, the better the adhesion.

[0104] (2) Electrolyte immersion test: Cut the composite current collector into 5cm*5cm pieces and place them in lithium-ion battery electrolyte (Sichuan Tianci, ZHKC01). Seal and immerse at 85℃ for 3 days. Observe whether the copper layer of the composite current collector falls off after immersion.

[0105] (3) Elongation at break: The elongation at break was measured using a universal testing machine (Dongguan Lixian Instrument Technology Co., Ltd., model: HZ-1004B). The composite current collector has a length of 200mm and a width of 15mm.

[0106] (4) Tensile strength: The tensile strength was measured using a universal testing machine (Dongguan Lixian Instrument Technology Co., Ltd., model: HZ-1004B). The composite current collector has a length of 200mm and a width of 15mm.

[0107] The composite current collectors prepared from the adhesive compositions of each embodiment and comparative example were tested according to the above test methods. The results are shown in Table 2.

[0108] Furthermore, the performance test of Example A in Table 2 differs from that of Example 5 in that the palladium ion content in the activation solution in step (4) of the specific preparation process of the composite current collector is 2 ppm. The performance test of Comparative Example B in Table 2 differs from that of Example 5 in that step (1) is not performed in the specific preparation process of the composite current collector, and only steps (2) to (8) are performed to obtain the composite current collector.

[0109] Table 2

[0110] As can be seen from Table 2: The copper layer adhesion of the composite current collectors prepared in Examples 5-10 and Example A all reached 4.8 N / cm or higher, the elongation at break all reached 10.8% or higher, and the tensile strength all reached 202 MPa or higher. The copper layer did not fall off after accelerated immersion in electrolyte. This indicates that using the adhesive composition made of the modified chlorinated polyolefin of the present invention as the adhesive layer of the composite current collector can effectively improve the adhesion of the metal layer, as well as improve the elongation at break, tensile strength and electrolyte immersion resistance of the composite current collector.

[0111] A comparison between Example 5 and Example A shows that even with a low palladium content in the activation solution used during the activation process (Example A, 2 ppm), the formation of copper in electroless plating can be effectively catalyzed, and the properties of the composite current collector remain good.

[0112] Comparative Example 1 used an adhesive composition made of unmodified chlorinated polyolefin as the adhesive layer of the composite current collector, resulting in poor performance of the composite current collector.

[0113] Comparative Example B, which did not use a binder composition, resulted in a composite current collector with poor performance.

[0114] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A modified chlorinated polyolefin, characterized in that, It is obtained by first alkylating a chlorinated polyolefin with a first amine and then acidifying it, or by quaternizing a chlorinated polyolefin with a second amine. The first amine is a primary amine and / or a secondary amine; the second amine is a tertiary amine.

2. The modified chlorinated polyolefin according to claim 1, characterized in that, The chlorinated polyolefin has a chlorine content of 20~70 wt.%; and / or The chlorinated polyolefin in the modified chlorinated polyolefin is at least one of chlorinated polypropylene or chlorinated polyethylene.

3. The modified chlorinated polyolefin according to claim 1, characterized in that, The first amine is a monoamine; Preferably, the structural formula of the first amine is as follows: R1, R2, and R3 are each independently selected from hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are substituted or unsubstituted by one or more heteroatoms selected from nitrogen, oxygen, and sulfur; and at least one of R1, R2, and R3 is not H.

4. The modified chlorinated polyolefin according to claim 1, characterized in that, The second amine is a monoamine; Preferably, the structural formula of the second amine is as follows: R4, R5 and R6 are each independently selected from substituted or unsubstituted alkyl groups having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 30 carbon atoms, substituted or unsubstituted monoalkylamino groups having 1 to 30 carbon atoms, substituted or unsubstituted dialkylamino groups, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms, and substituted or unsubstituted aromatic heterocycles having 4 to 30 carbon atoms; in the aromatic heterocycle, one or more carbon atoms are replaced or not replaced by one or more heteroatoms of nitrogen, oxygen and sulfur.

5. A method for preparing modified chlorinated polyolefin, characterized in that, Includes the following steps: The chlorinated polyolefin is first alkylated with a first amine, and then acidified to obtain the modified chlorinated polyolefin. Alternatively, the chlorinated polyolefin may undergo a quaternization reaction with a second amine to obtain the modified chlorinated polyolefin. The first amine is a primary amine and / or a secondary amine; the second amine is a tertiary amine.

6. The preparation method according to claim 5, characterized in that, The molar ratio of chlorine to the first amine in the chlorinated polyolefin is 1:(1.5~6). and / or The alkylation reaction is carried out at a temperature of 60-80°C for 3-5 hours. and / or The molar ratio of chlorine to the second amine in the chlorinated polyolefin is 1:(1.5~6). and / or The quaternization reaction is carried out at a temperature of 60-80°C for 3-5 hours.

7. An adhesive composition, characterized in that, Components including the following mass percentages: 5-20% of the modified chlorinated polyolefin as described in any one of claims 1-4 or the modified chlorinated polyolefin prepared by any one of claims 5-6. Solvent balance.

8. The use of the adhesive composition of claim 7 in the preparation of composite current collectors.

9. A composite current collector, characterized in that, It includes a polymer substrate layer, an adhesive layer, and a metal layer; the adhesive layer is obtained by curing the adhesive composition of claim 7.

10. The method for preparing the composite current collector according to claim 9, characterized in that, Includes the following steps: The adhesive combination described in claim 7 is coated onto the surface of a polymer substrate, cured, activated, and then subjected to chemical plating and electroplating to obtain the composite current collector.

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