Lithium battery packaging aluminum plastic film and preparation process thereof

Abstract

The invention discloses a lithium battery packaging aluminum plastic film and a preparation process thereof, the lithium battery packaging aluminum plastic film comprises a nylon layer, an aluminum foil layer and a polypropylene film layer, an outer adhesive layer is arranged between the nylon layer and the aluminum foil layer, and an inner adhesive layer is arranged between the aluminum foil layer and the polypropylene film layer; the inner adhesive layer is prepared from the following components in parts by weight: 100 parts of maleic anhydride modified styrene, 10 to 20 parts of chlorinated polypropylene butylene, 2 to 5 parts of hydrogenated bisphenol A epoxy resin, 1 to 3 parts of curing agent, 0.5 to 1 part of tackifying resin, 2 to 5 parts of benzyl dimethylamine or pyridine, 0.5 to 2 parts of 3, 5-diethyltoluenediamine, 0.2 to 1 part of antioxidant and 200 to 300 parts of organic solvent. According to the invention, the bonding strength stability between the aluminum foil layer and the polypropylene film layer in a 60 DEG C high-temperature hot bath exceeds 48 hours, so that the high-temperature resistance and high-humidity resistance of the aluminum plastic film are improved, and the reliability and weather resistance of the lithium battery packaging aluminum plastic film are improved.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum-plastic films, and in particular to an aluminum-plastic film for lithium battery packaging. Background Art

[0002] In recent years, with the development of new energy vehicles, 3C digital products and microelectronics technology, the demand for lithium-ion batteries has continued to grow. As an important component of lithium-ion batteries, aluminum-plastic film plays the role of encapsulating electrolyte and protecting batteries. It is mainly composed of nylon layer, outer adhesive layer, aluminum foil layer, inner adhesive layer and polypropylene film layer. The existing aluminum-plastic film is prone to delamination between the aluminum foil layer and the polypropylene film layer in a high temperature and humidity environment. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a lithium battery encapsulation aluminum-plastic film, wherein the bonding strength stability between the aluminum foil layer and the polypropylene film layer of the lithium battery encapsulation aluminum-plastic film in a high-temperature hot water bath at 60°C exceeds 48 hours, the high temperature and high humidity resistance of the aluminum-plastic film is improved, and the reliability and weather resistance of the lithium battery encapsulation aluminum-plastic film are improved. At the same time, a preparation process for the above lithium battery encapsulation aluminum-plastic film is provided.

[0004] To achieve the above object, the technical scheme of the aluminum-plastic film adopted by the present invention is: a lithium battery encapsulation aluminum-plastic film, the lithium battery encapsulation aluminum-plastic film comprising: a nylon layer, an aluminum foil layer and a polypropylene film layer, an outer adhesive layer is provided between the nylon layer and the aluminum foil layer, an inner adhesive layer is provided between the aluminum foil layer and the polypropylene film layer, and the inner adhesive layer is formed by an inner adhesive;

[0005] The internal adhesive is composed of the following components in parts by weight:

[0006]

[0007] The technical solution further improved in the above technical solution is as follows:

[0008] 1. In the above scheme, the organic solvent is at least one of benzene, toluene, xylene and cyclohexane.

[0009] 2. In the above scheme, the tackifying resin is at least one of a phenolic modified tackifying resin, a terpene tackifying resin, a rosin tackifying resin, and a phenolic tackifying resin.

[0010] 3. In the above scheme, the curing agent is at least one of isophorone diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

[0011] The technical solution of the preparation process adopted by the present invention is: a preparation process for the above-mentioned aluminum-plastic film for lithium battery packaging, comprising the following steps:

[0012] Step 1: first add 100 parts of maleic anhydride modified styrene, 10-20 parts of chlorinated polypropylene butene, and 2-5 parts of hydrogenated bisphenol A epoxy resin into 200-300 parts of organic solvent, and heat and stir;

[0013] Step 2: while stirring, add 2-5 parts of benzyldimethylamine or pyridine, 0.5-2 parts of 3,5-diethyltoluenediamine, 0.2-1 parts of antioxidant, 0.5-1 parts of tackifying resin, and 1-3 parts of curing agent in sequence, and filter out insoluble matter to obtain an adhesive coating agent;

[0014] Step 3, applying the adhesive coating agent to the surface of the polypropylene film layer;

[0015] Step 4: Place the coated polypropylene film layer in an oven and bake for 2 to 4 hours, with the oven temperature set at 80 to 90°C;

[0016] Step 5: The polypropylene film layer obtained in step 4 is laminated with the aluminum foil layer by hot pressing and then placed in a curing room for curing for 3 to 5 days.

[0017] The technical solution further improved in the above technical solution is as follows:

[0018] 1. In the above scheme, the organic solvent is at least one of benzene, toluene, xylene and cyclohexane.

[0019] 2. In the above scheme, the tackifying resin is at least one of a phenolic modified tackifying resin, a terpene tackifying resin, a rosin tackifying resin, and a phenolic tackifying resin.

[0020] 3. In the above scheme, the curing agent is at least one of isophorone diisocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

[0021] 4. In the above scheme, the aging temperature is 40-42°C.

[0022] 5. In the above scheme, the temperature of heating and stirring in step 1 is 40°C and the time is 20 to 30 hours.

[0023] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0024] The invention discloses an aluminum-plastic film for lithium battery packaging and a preparation process thereof. The aluminum-plastic film is prepared by adding 2-5 parts of benzyldimethylamine or pyridine and 0.5-2 parts of 3,5-diethyltoluenediamine to 100 parts of maleic anhydride-modified styrene, 10-20 parts of chlorinated polypropylene butene and 2-5 parts of hydrogenated bisphenol A epoxy resin. The bonding strength stability between the aluminum foil layer and the polypropylene film layer is greater than 48 hours in a high-temperature hot water bath at 60°C, thereby improving the high temperature and high humidity resistance of the aluminum-plastic film and improving the reliability and weather resistance of the aluminum-plastic film for lithium battery packaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attached Figure 1 It is a schematic diagram of the structure of the aluminum-plastic film for packaging lithium batteries of the present invention.

[0026] In the above figures: 1, nylon layer; 2, aluminum foil layer; 3, polypropylene film layer; 4, outer adhesive layer; 5, inner adhesive layer. DETAILED DESCRIPTION

[0027] The present invention can be further understood through the specific embodiments given below, but they are not intended to limit the present invention.

[0028] The present invention will be further described below in conjunction with embodiments:

[0029] Embodiments 1 to 4: A lithium battery encapsulation aluminum-plastic film, the lithium battery encapsulation aluminum-plastic film comprising: a nylon layer 1, an aluminum foil layer 2 and a polypropylene film layer 3, an outer adhesive layer 4 is provided between the nylon layer 1 and the aluminum foil layer 2, an inner adhesive layer 5 is provided between the aluminum foil layer 2 and the polypropylene film layer 3, and the inner adhesive layer 5 is formed by an inner adhesive;

[0030] The inner adhesive is composed of the following components in parts by weight, as described in Table 1:

[0031] Table 1

[0032] Components Example 1 Example 2 Example 3 Example 4 Maleic anhydride modified styrene 100 copies 100 copies 100 copies 100 copies Chlorinated Polypropylene Butylene 15 servings 10 servings 12 servings 15 servings Hydrogenated bisphenol A epoxy resin 4 servings 5 servings 2 servings 4 servings Curing agent 2 servings 1.5 servings 3 servings 2 servings Tackifying resin 0.6 parts 0.8 parts 0.6 parts 0.8 parts Benzyldimethylamine or pyridine 3 servings 4 servings 2 servings 3 servings 3,5-Diethyltoluenediamine 1 serving 1.5 servings 1 serving 0.8 parts Antioxidants 0.6 parts 0.3 parts 0.5 serving 0.3 parts Organic solvents 250 copies 250 copies 250 copies 250 copies .

[0033] In Example 1, the organic solvent is xylene, the tackifying resin is a phenolic modified tackifying resin, and the curing agent is toluene diisocyanate.

[0034] In Example 2, the organic solvent is cyclohexane, the tackifying resin is rosin tackifying resin, and the curing agent is hexamethylene diisocyanate.

[0035] In Example 3, the organic solvent is xylene, the tackifying resin is a phenolic tackifying resin, and the curing agent is isophorone diisocyanate.

[0036] In Example 4, the organic solvent is toluene, the tackifying resin is a terpene tackifying resin, and the curing agent is isophorone diisocyanate.

[0037] A preparation process for the above-mentioned aluminum-plastic film for lithium battery packaging comprises the following steps:

[0038] Step 1: first add maleic anhydride modified styrene, chlorinated polypropylene butene, and hydrogenated bisphenol A epoxy resin into an organic solvent and heat and stir;

[0039] Step 2: while stirring, add benzyldimethylamine or pyridine, 3,5-diethyltoluenediamine, antioxidant, tackifying resin, and curing agent in sequence, and filter out insoluble matter to obtain an adhesive coating agent;

[0040] Step 3: coating the surface of the polypropylene film layer 3 with an adhesive coating agent;

[0041] Step 4: Place the coated polypropylene film layer 3 in an oven and bake for 2 to 4 hours, with the oven temperature set at 85° C.;

[0042] Step 5: The polypropylene film layer 3 obtained in step 4 is heat-pressed and laminated with the aluminum foil layer 2, and then placed in a curing room for 4 days at a curing temperature of 40°C.

[0043] The heating and stirring temperature in the above step 1 is 40° C. and the time is 25 h.

[0044] Comparative Examples 1 to 3: A lithium battery encapsulation aluminum-plastic film, the lithium battery encapsulation aluminum-plastic film comprising: a nylon layer 1, an aluminum foil layer 2 and a polypropylene film layer 3, an outer adhesive layer 4 is provided between the nylon layer 1 and the aluminum foil layer 2, an inner adhesive layer 5 is provided between the aluminum foil layer 2 and the polypropylene film layer 3, and the inner adhesive layer 5 is formed by an inner adhesive;

[0045] The inner adhesive is composed of the following components in parts by weight, as described in Table 2:

[0046] Table 2

[0047] Components Comparative Example 1 Comparative Example 2 Comparative Example 3 Maleic anhydride modified styrene 100 copies 100 copies 100 copies Chlorinated Polypropylene Butylene 15 servings 15 servings 15 servings Hydrogenated bisphenol A epoxy resin 4 servings 4 servings 4 servings Curing agent 2 servings 2 servings 2 servings Tackifying resin 0.6 parts 0.6 parts 0.6 parts Benzyldimethylamine or pyridine - 3 servings - 3,5-Diethyltoluenediamine 1 serving - - Antioxidants 0.6 parts 0.6 parts 0.6 parts Organic solvents 250 copies 250 copies 250 copies .

[0048] In Comparative Examples 1 to 3, the organic solvent is xylene, the tackifying resin is a phenolic modified tackifying resin, and the curing agent is toluene diisocyanate.

[0049] The preparation process steps of the comparative example are the same as those of the example.

[0050] Ten samples of the lithium battery encapsulation aluminum-plastic films obtained in Examples 1 to 4 and Comparative Examples 1 to 3 were prepared respectively, and placed in a water bath environment at 60° C. for 10 hours to observe whether the aluminum foil layer and the polypropylene film layer in each sample were delaminated. The corresponding observation results were statistically shown in Table 3:

[0051] Table 3

[0052]

[0053] As shown in the evaluation results of Table 3, the aluminum-plastic films for lithium battery packaging obtained in Examples 1 to 4 of the present invention did not show delamination of the aluminum foil layer and the polypropylene film layer in a high-temperature hot water bath at 60°C.

[0054] In the lithium battery encapsulation aluminum-plastic film of comparative example 1, no benzyldimethylamine or pyridine was added to the inner adhesive layer, and 5 samples showed delamination in 48 hours at a high temperature hot water bath of 60°C. In the lithium battery encapsulation aluminum-plastic film of comparative example 2, no 3,5-diethyltoluenediamine was added to the inner adhesive layer, and 4 samples showed delamination in 48 hours at a high temperature hot water bath of 60°C. In the lithium battery encapsulation aluminum-plastic film of comparative example 3, no benzyldimethylamine or pyridine or 3,5-diethyltoluenediamine was added to the inner adhesive layer, and 6 samples showed delamination in 48 hours at a high temperature hot water bath of 60°C. In the lithium battery encapsulation aluminum-plastic film of this embodiment, the bonding strength stability between the aluminum foil layer and the polypropylene film layer reached 48 hours under a high temperature hot water bath of 60°C.

[0055] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A lithium battery encapsulation aluminum-plastic film, characterized in that: The lithium battery packaging aluminum-plastic film comprises: a nylon layer (1), an aluminum foil layer (2) and a polypropylene film layer (3); an outer adhesive layer (4) is provided between the nylon layer (1) and the aluminum foil layer (2); an inner adhesive layer (5) is provided between the aluminum foil layer (2) and the polypropylene film layer (3); the inner adhesive layer (5) is formed by an inner adhesive; The internal adhesive is composed of the following components in parts by weight: 100 parts of maleic anhydride modified styrene, Chlorinated polypropylene butene 10-20 parts, 2~5 parts of hydrogenated bisphenol A epoxy resin, 1~3 parts of curing agent, 0.5~1 part of tackifying resin, Benzyldimethylamine or pyridine 2-5 parts, 0.5-2 parts of 3,5-diethyltoluenediamine, Antioxidant 0.2~1 part, 200~300 parts of organic solvent.

2. The aluminum-plastic film for lithium battery packaging according to claim 1, characterized in that: The organic solvent is at least one of benzene, toluene, xylene and cyclohexane.

3. The aluminum-plastic film for lithium battery packaging according to claim 1, characterized in that: The tackifying resin is at least one of a phenolic modified tackifying resin, a terpene tackifying resin, a rosin tackifying resin, and a phenolic tackifying resin.

4. The aluminum-plastic film for lithium battery packaging according to claim 1, characterized in that: The curing agent is at least one of isophorone diisocyanate, toluene diisocyanate and hexamethylene diisocyanate.

5. A process for preparing the aluminum-plastic film for lithium battery packaging according to claim 1, characterized in that: The following steps are involved: Step 1: first add 100 parts of maleic anhydride modified styrene, 10-20 parts of chlorinated polypropylene butene, and 2-5 parts of hydrogenated bisphenol A epoxy resin into 200-300 parts of organic solvent, and heat and stir; Step 2: while stirring, add 2-5 parts of benzyldimethylamine or pyridine, 0.5-2 parts of 3,5-diethyltoluenediamine, 0.2-1 parts of antioxidant, 0.5-1 parts of tackifying resin, and 1-3 parts of curing agent in sequence, and filter out insoluble matter to obtain an adhesive coating agent; Step 3: coating the surface of the polypropylene film layer (3) with an adhesive coating agent; Step 4: Place the coated polypropylene film layer (3) in an oven and bake for 2 to 4 hours, with the oven temperature set at 80 to 90° C.; Step 5: The polypropylene film layer (3) obtained in step 4 is laminated with the aluminum foil layer (2) by hot pressing and then placed in a curing room for 3 to 5 days.

6. The process for preparing the aluminum-plastic film for lithium battery packaging according to claim 5, characterized in that: The organic solvent is at least one of benzene, toluene, xylene and cyclohexane.

7. The process for preparing the aluminum-plastic film for lithium battery packaging according to claim 5, characterized in that: The tackifying resin is at least one of a phenolic modified tackifying resin, a terpene tackifying resin, a rosin tackifying resin, and a phenolic tackifying resin.

8. The process for preparing the aluminum-plastic film for lithium battery packaging according to claim 5, characterized in that: The curing agent is at least one of isophorone diisocyanate, toluene diisocyanate and hexamethylene diisocyanate.

9. The aluminum-plastic film for lithium battery packaging according to claim 5, characterized in that: The aging temperature is 40-42°C.

10. The aluminum-plastic film for lithium battery packaging according to claim 5, characterized in that: The heating and stirring temperature in the step 1 is 40° C. and the time is 20 to 30 hours.

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