Code spraying adhesive tape for power battery and preparation method of code spraying adhesive tape

Abstract

The invention discloses a code spraying adhesive tape for a power battery. The code spraying adhesive tape sequentially comprises a pressure-sensitive adhesive layer, an ink layer, a base material layer and a release layer from top to bottom, the pressure-sensitive adhesive layer is made of acrylate pressure-sensitive adhesive, and the ink layer is made of UV photocuring ink. The toluene diisocynate, the maleic anhydride curing agent and the melamino-formaldehyde resin are combined together to serve as the curing agent, and excellent peeling strength can be maintained while the two-dimensional code can be rapidly recognized. Polysiloxane acrylate and bisphenol A type epoxy acrylate are combined for use in the ink, light curing of the ink can be achieved, the ink and an acrylate sensitive adhesive have good combination characteristics, and sprayed codes can be rapidly recognized and are not prone to falling off.

Description

Technical Field

[0001] The present invention relates to the field of lithium battery assembly, and particularly to an inkjet printing tape for power batteries and a preparation method thereof. Background Art

[0002] With the development of technology, power batteries are increasingly widely used in transportation vehicles. Power batteries have high energy and high power, and long service life. In order to reduce the replacement frequency and cost of power batteries, it is necessary to continuously develop safer and more reliable power batteries. With the increasing application volume of power batteries, the quality control of the safety properties of power batteries requires higher traceability. Inkjet printing on power batteries can achieve continuous monitoring of power batteries. However, inkjet printing needs to be immersed in the electrolyte, which puts higher requirements on the performance of the tape carrying the inkjet printing. Therefore, it is crucial to develop an inkjet printing tape that is resistant to electrolyte corrosion, has high viscosity, and can be quickly recognized by inkjet printing.

[0003] Chinese invention patent CN115584217B discloses an identifiable termination tape. By combining suitable photoactive oligomers, macromolecular terminal carboxyl acrylic resins, and photoinitiators, a stable polymer network is constructed, so that the coloring coating adheres firmly to the selected suitable coating substrate. However, the viscosity of the adhesive layer is low, and the bonding strength needs to be improved. Chinese invention patent CN117683486A discloses an adhesive and an inkjet printing tape using the same. By simultaneously introducing modified styrene-isoprene-styrene block copolymer, hydrogenated nitrile rubber, amorphous polyalpha olefin, tackifying resin, reactive liquid rubber and other materials, the electrolyte resistance performance and chemical stability of the inkjet printing tape can be enhanced. However, the ink is prone to decolorization, and the adhesion between the adhesive and the ink is poor. Summary of the Invention

[0004] In order to develop an inkjet printing tape that is resistant to electrolyte corrosion, has high viscosity, and can be quickly recognized by inkjet printing, a first aspect of the present invention provides an inkjet printing tape for power batteries. The inkjet printing tape sequentially includes a pressure-sensitive adhesive layer, an ink layer, a substrate layer, and a release layer from top to bottom. The pressure-sensitive adhesive layer is an acrylate pressure-sensitive adhesive, and the ink layer is a UV-curable ink.

[0005] As a preferred embodiment, in parts by weight, the raw materials for preparing the UV-curable ink include 1-3 parts of a dispersant, 0.4-2.2 parts of a surfactant, 18-28 parts of a UV oligomer, 55-85 parts of a UV monomer, 5-15 parts of a photoinitiator, 0.2-2.2 parts of a light stabilizer, 0.2-2.2 parts of a heat stabilizer, and 2-5 parts of carbon black.

[0006] As a preferred embodiment, the UV oligomer is a polysiloxane acrylate, and the UV monomer is an epoxy acrylate monomer.

[0007] As a preferred embodiment, the UV monomer is bisphenol A epoxy acrylate monomer. Preferably, the UV monomer is ethoxylated trimethylolpropane triacrylate (TMPTA).

[0008] As a preferred embodiment, the dispersant is dipropylene glycol diacrylate, the surfactant is cetyltrimethylammonium bromide. The photoinitiator is benzophenone. The light stabilizer is Chimassorb 944, and the heat stabilizer is Irganox 1010.

[0009] As a preferred embodiment, based on parts by weight, the raw materials for preparing the acrylate pressure-sensitive adhesive include 34 - 91 parts of acrylic monomer, 0.1 - 1 part of initiator, 3 - 10 parts of curing agent, 4 - 6 parts of color paste, and also include Solvent I, Solvent II and Solvent III.

[0010] As a preferred embodiment, based on parts by weight, the acrylic monomer includes 1 - 3 parts of acrylic acid, 1 - 3 parts of hydroxypropyl acrylate, 1 - 10 parts of isobornyl acrylate, 1 - 5 parts of glycidyl methacrylate, 25 - 45 parts of isooctyl acrylate, 1 - 5 parts of lauryl methacrylate, 1 - 5 parts of cyclohexyl acrylate, 1 - 5 parts of cyclopentyl acrylate, 1 - 5 parts of cyclohexylmethyl acrylate, 1 - 5 parts of dicyclopentadienyl acrylate.

[0011] As a preferred embodiment, the curing agent is selected from at least one of isocyanate curing agents, maleic anhydride curing agents, and melamine formaldehyde resins.

[0012] As a preferred embodiment, the isocyanate curing agent is toluene diisocyanate. The maleic anhydride curing agent is Narconate 100 maleic anhydride. The melamine formaldehyde resin is Resimene 710.

[0013] As a preferred embodiment, the curing agent is a combination of toluene diisocyanate and Narconate 100 maleic anhydride, and the weight ratio is (1 - 5) : (2 - 5); preferably, the weight ratio of toluene diisocyanate to Narconate 100 maleic anhydride is 3 : 4.

[0014] As a preferred embodiment, the curing agent is a combination of toluene diisocyanate, Narconate 100 maleic anhydride, and Resimene 710 melamine formaldehyde resin.

[0015] As a preferred embodiment, the weight ratio of toluene diisocyanate, Narconate 100 maleic anhydride, and Resimene 710 melamine formaldehyde resin is (1 - 4) : (1 - 3) : (1 - 3).

[0016] As a preferred embodiment, the weight ratio of the toluene diisocyanate, Narconate 100 maleic anhydride, and Resimene 710 melamine formaldehyde resin is 2.5:2:2.

[0017] During the experiment, the applicant found that by using a combination of toluene diisocyanate and a maleic anhydride-based curing agent, a pressure-sensitive adhesive with a thickness of 25 μm can be obtained, which has high viscosity and is resistant to electrolytes for battery tapes. It is speculated that the possible reason is that the -NCO contained in the toluene diisocyanate and the maleic anhydride-based curing agent can react with acrylic monomers to form a dense cross-linked network, improving the electrolyte resistance of the adhesive layer.

[0018] The inventor further found during the experiment that when toluene diisocyanate, a maleic anhydride-based curing agent, and melamine formaldehyde resin are combined as curing agents, the two-dimensional code can be quickly recognized while maintaining excellent peel strength. The reason may be that the introduction of melamine formaldehyde resin can expand the cross-linking mode of the cross-linked network, the cured ink after light curing has high recognition, and combined with the high viscosity of the pressure-sensitive adhesive, the quick recognition of the two-dimensional code is achieved.

[0019] As a preferred embodiment, the initiator is benzoyl peroxide.

[0020] As a preferred embodiment, the color paste is phthalocyanine blue paste or cobalt green paste.

[0021] As a preferred embodiment, the solvent I is an alkane and the solvent II is an ester solvent.

[0022] As a preferred embodiment, the solvent I is heptane; the solvent II is ethyl acetate, and the solvent III is toluene.

[0023] In the present invention, when the ink jet coding is adhered to the acrylate pressure-sensitive adhesive and alkanes, ester solvents, and toluene are used as solvents, it is possible to avoid degrading the ink jet coding, extend the service life of the ink jet coding, and prevent it from falling off easily.

[0024] The second aspect of the present invention provides a method for preparing a jet-coded tape for power batteries, including the following steps:

[0025] S1 Prepare the acrylate pressure-sensitive adhesive and set it aside;

[0026] S2 Prepare the UV-curable ink and set it aside;

[0027] S3 Inkjet the UV-curable ink onto the substrate layer and then perform light curing, with the light intensity being 100 - 120 mW / cm 2 ;

[0028] S4 Provide a release layer on the side of the substrate layer away from the ink layer;

[0029] S5 Extrusion coat an acrylate pressure-sensitive adhesive above the cured ink layer;

[0030] S6 Cure and wind up to obtain a semi-finished tape.

[0031] As a preferred embodiment, the preparation method of the inkjet printing tape for power batteries includes the following steps:

[0032] S1 Prepare an acrylate pressure-sensitive adhesive for standby;

[0033] S2 Prepare a UV curable ink for standby;

[0034] S3 Inkjet the UV curable ink onto the cleaned substrate layer, and then perform UV curing with a light intensity of 100 - 120mW / cm 2 ;

[0035] S4 Provide a release layer on the side of the substrate layer away from the ink layer, and cure it at 60 - 120°C for 5 - 20 minutes;

[0036] S5 Extrusion coat an acrylate pressure-sensitive adhesive above the cured ink layer;

[0037] S6 Place it at 60 - 120°C for curing and drying for 5 - 12 minutes, and wind up to obtain a semi-finished tape.

[0038] As a preferred embodiment, the preparation method of the acrylate pressure-sensitive adhesive in step S1 is as follows:

[0039] M1 Mix acrylate monomers, introduce nitrogen, heat to 50 - 70°C under nitrogen protection, slowly stir for 5 - 7 hours, then add an initiator and continue to react for 4 - 6 hours to obtain a pre-reacted colloid;

[0040] M2 Add solvent I to dilute and stir the pre-reacted colloid, add a curing agent during stirring, mix evenly, add a color paste, stir evenly to obtain a pre-cured colloid, and continue to add solvent II and solvent III to dilute it to a coatable state for standby.

[0041] As a preferred embodiment, the preparation method of the UV curable ink in step S2 is as follows:

[0042] Mix the preparation raw materials and stir at room temperature for 20 - 40 minutes. After sufficient mixing, set aside for standby.

[0043] As a preferred embodiment, the addition amount of solvent I is: make the mass concentration of the pre-reacted colloid 30 - 50%, preferably make the mass concentration of the pre-reacted colloid 40%.

[0044] As a preferred embodiment, the mass ratio of the solvent II to the pre-cured colloid is (1-3):1; the solvent III is 5-7% of the mass of the pre-cured colloid. Preferably, the mass ratio of the solvent II to the pre-cured colloid is 1:1; the solvent III is 6% of the mass of the pre-cured colloid.

[0045] As a preferred embodiment, the photocuring time in the step S3 is 10-50 s. Preferably, the photocuring time in the step S3 is 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s.

[0046] As a preferred embodiment, the coating thickness of the acrylate pressure-sensitive adhesive in the step S5 is 5-50 μm. Preferably, the coating thickness of the acrylate pressure-sensitive adhesive in the step S5 is 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm.

[0047] As a preferred embodiment, the substrate layer is a PET substrate, and the thickness of the PET substrate is 25-75 μm. Preferably, the thickness of the PET substrate is 25, 50, 75 μm.

[0048] As a preferred embodiment, the release layer is a non-silicon release agent, and the non-silicon release agent is Polywax1000 polyethylene wax.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) For the inkjet printing tape for power batteries of the present invention, a combination of toluene diisocyanate and maleic anhydride-based curing agent is used, and the pressure-sensitive adhesive with a thickness of 25 μm obtained has good electrolyte resistance.

[0051] (2) For the inkjet printing tape for power batteries of the present invention, toluene diisocyanate, maleic anhydride-based curing agent and melamine formaldehyde resin are combined as curing agents together. The two-dimensional code can be quickly recognized while maintaining excellent peel strength.

[0052] (3) For the inkjet printing tape for power batteries of the present invention, a combination of polysiloxane acrylate and bisphenol A type epoxy acrylate is used in the ink, which can achieve photocuring of the ink. The ink and the acrylate pressure-sensitive adhesive have good binding properties, and the inkjet printing can be quickly recognized and is not easy to fall off.

[0053] (4) For the inkjet printing tape for power batteries of the present invention, the pressure-sensitive adhesive and the inkjet printing are on the same side of the substrate. The ink has good adhesion to the substrate, is not easily wiped off and is not faded by the solvent of the pressure-sensitive adhesive. The ink and the glue also have good binding adhesion.

[0054] (5) The inkjet printing tape for power batteries of the present invention can achieve the effects of easy QR code recognition, high efficiency, and low comprehensive cost by spraying QR codes and clear codes without investing in expensive laser coding machines. Detailed implementation manners

[0055] Example 1

[0056] An inkjet printing tape for power batteries, the inkjet printing tape sequentially includes a pressure-sensitive adhesive layer, an ink layer, a substrate layer, and a release layer from top to bottom; the pressure-sensitive adhesive layer is an acrylate pressure-sensitive adhesive, and the ink layer is a UV curable ink.

[0057] By weight, the preparation raw materials of the UV curable ink include 2 parts of a dispersant, 1.3 parts of a surfactant, 23 parts of a UV oligomer, 70 parts of a UV monomer, 10 parts of a photoinitiator, 1.2 parts of a light stabilizer, 1.2 parts of a heat stabilizer, and 3 parts of carbon black.

[0058] The UV oligomer is polysiloxane acrylate, and the UV monomer is ethoxylated trimethylolpropane triacrylate.

[0059] The polysiloxane acrylate is Sartomer CN9800.

[0060] The dispersant is dipropylene glycol diacrylate, and the surfactant is cetyltrimethylammonium bromide. The photoinitiator is benzophenone. The light stabilizer is Chimassorb 944, and the heat stabilizer is Irganox1010.

[0061] By weight, the preparation raw materials of the acrylate pressure-sensitive adhesive include 62.5 parts of an acrylic monomer, 0.5 part of an initiator, 7 parts of a curing agent, 5 parts of a color paste, and also include Solvent I, Solvent II, and Solvent III.

[0062] By weight, the acrylic monomer includes 2 parts of acrylic acid, 2 parts of hydroxypropyl acrylate, 5 parts of isobornyl acrylate, 3 parts of glycidyl methacrylate, 35 parts of isooctyl acrylate, 3 parts of lauryl methacrylate, 3 parts of cyclohexyl acrylate, 3 parts of cyclopentyl acrylate, 3 parts of cyclohexylmethyl acrylate, and 3 parts of dicyclopentadienyl acrylate.

[0063] The curing agent is a combination of toluene diisocyanate and Narconate 100 maleic anhydride, and the weight ratio is 3:4.

[0064] The initiator is benzoyl peroxide. The color paste is phthalocyanine blue paste.

[0065] The Solvent I is heptane; the Solvent II is ethyl acetate, and the Solvent III is toluene.

[0066] A method for preparing a coding tape for a power battery comprises the following steps:

[0067] S1 prepares an acrylic pressure-sensitive adhesive for standby use;

[0068] S2 prepares UV light curing ink for standby use;

[0069] S3 sprays UV light-curable ink onto the cleaned substrate layer and then light cures it at a light intensity of 110mW / cm 2 ;

[0070] S4: a release layer is provided on the side of the substrate layer away from the ink layer, and the substrate layer is cured at 100°C for 15 minutes;

[0071] S5 extrusion-coating an acrylic pressure-sensitive adhesive on the cured ink layer;

[0072] S6 was placed at 100°C for curing for 10 minutes and dried, and then rolled up to obtain a semi-finished adhesive tape.

[0073] The preparation method of the acrylic pressure-sensitive adhesive in step S1 is as follows:

[0074] M1: Mix the acrylic acid monomers, introduce nitrogen, heat to 60°C under nitrogen protection, stir slowly for 0.5h, then add the initiator, continue the reaction for 5h, and obtain a pre-reaction colloid;

[0075] M2 is added with solvent I to dilute and stir the pre-reacted colloid. During the stirring process, a curing agent is added. After mixing evenly, a color paste is added and stirred evenly to obtain a pre-cured colloid. Solvent II and solvent III are continuously added to dilute the colloid to a coatable state and set aside.

[0076] The amount of solvent I added is such that the mass concentration of the pre-reacted colloid is 40%. The mass ratio of solvent II to pre-cured colloid is 1:1; and the amount of solvent III is 6% of the mass of the pre-cured colloid.

[0077] The preparation method of the UV light curing ink in step S2 is as follows:

[0078] The prepared raw materials were mixed and stirred at room temperature for 60 min. After being fully mixed, they were set aside.

[0079] The light curing time in step S3 is 30 seconds.

[0080] The coating thickness of the acrylic pressure-sensitive adhesive in step S5 is 10 μm.

[0081] The substrate layer is a PET substrate, and the thickness of the PET substrate is 25 μm.

[0082] The release layer is a non-silicon release agent Polywax 1000 polyethylene wax.

[0083] Example 2

[0084] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 1, except that the coating thickness of the acrylate pressure-sensitive adhesive in step S5 is 5 μm.

[0085] Example 3

[0086] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 1, except that the coating thickness of the acrylate pressure-sensitive adhesive in step S5 is 15 μm.

[0087] Example 4

[0088] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 1, except that the photocuring time in step S3 is 50 s.

[0089] Example 5

[0090] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 1, except that the photocuring time in step S3 is 10 s.

[0091] Example 6

[0092] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 4, except that the curing agent is Resimene 710 melamine formaldehyde resin.

[0093] Example 7

[0094] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 6, except that the curing agent is a combination of toluene diisocyanate and Resimene 710 melamine formaldehyde resin, and the weight ratio is 3.5:3.

[0095] Example 8

[0096] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 6, except that the curing agent is a combination of Narconate 100 maleic anhydride and Resimene 710 melamine formaldehyde resin, and the weight ratio is 3.5:3.

[0097] Example 9

[0098] A coding tape for power battery and its preparation method. The specific implementation is the same as that of Example 6, except that the curing agent is a combination of toluene diisocyanate, Narconate 100 maleic anhydride, and Resimene 710 melamine formaldehyde resin, and the weight ratio is 2.5:2:2.

[0099] Example 10

[0100] A coding tape for power batteries and its preparation method. The specific implementation is the same as that of Example 6, except that the curing agent is Narconate 100 maleic anhydride.

[0101] Comparative Example 1

[0102] A coding tape for power batteries and its preparation method. The specific implementation is the same as that of Example 4, except that the addition amount of the curing agent is 0 parts by weight.

[0103] Comparative Example 2

[0104] A coding tape for power batteries and its preparation method. The specific implementation is the same as that of Example 4, except that the coating thickness of the acrylate pressure-sensitive adhesive in step S5 is 1 μm.

[0105] Comparative Example 3

[0106] A coding tape for power batteries and its preparation method. The specific implementation is the same as that of Example 4, except that the coating thickness of the acrylate pressure-sensitive adhesive in step S5 is 100 μm.

[0107] Performance test

[0108] 1. Adhesion test:

[0109] The prepared product is made into a sample piece, and the 180° peel strength of the sample is tested according to the regulations in GB / T 2792-2014. Keep the temperature around the test environment at 23±2°C, the humidity at 50±5%, and the test speed at 300 mm / min. Take the average value after multiple tests.

[0110] 2. Determination of electrolyte resistance performance:

[0111] The samples of the examples and comparative examples are respectively pasted with aluminum foil, and the samples are immersed in the electrolyte at 85°C for 4 h. Conduct parallel experiments 3 times. After the experiment, observe whether the coding tape shows peeling or delamination.

[0112] 3. Two-dimensional code recognition test:

[0113] Take 10 samples each from the examples and comparative examples for two-dimensional code recognition test to test whether the samples can be easily scanned and recognized. Recognizing 20 is fast recognition, recognizing 10 is relatively fast recognition, and recognizing 5 is slow recognition.

[0114] The test results are shown in Table 1.

[0115] Table 1

[0116]

[0117]

Claims

1. A coding tape for power batteries, characterized in that: The inkjet printing tape comprises a pressure-sensitive adhesive layer, an ink layer, a substrate layer, and a release layer from top to bottom; the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive, and the ink layer is a UV light-curable ink.

2. The inkjet printing tape for power batteries according to claim 1, characterized in that: In parts by weight, the raw materials for preparing the UV light-curing ink include 1-3 parts of dispersant, 0.4-2.2 parts of surfactant, 18-28 parts of UV oligomer, 55-85 parts of UV monomer, 5-15 parts of photoinitiator, 0.2-2.2 parts of light stabilizer, 0.2-2.2 parts of heat stabilizer, and 2-5 parts of carbon black.

3. The inkjet printing tape for power battery according to claim 1, characterized in that: The UV oligomer is polysiloxane acrylate, and the UV monomer is epoxy acrylate monomer.

4. The inkjet printing tape for power batteries according to claim 1, characterized in that: The raw materials for preparing the acrylic pressure-sensitive adhesive include 34-91 parts of acrylic monomer, 0.1-1 parts of initiator, 3-10 parts of curing agent, 4-6 parts of color paste, and solvent I, solvent II, and solvent III in parts by weight.

5. The inkjet printing tape for power battery according to claim 4, characterized in that: In parts by weight, the acrylic monomer includes 1-3 parts of acrylic acid, 1-3 parts of hydroxypropyl acrylate, 1-10 parts of isobornyl acrylate, 1-5 parts of glycidyl methacrylate, 25-45 parts of isooctyl acrylate, 1-5 parts of lauryl methacrylate, 1-5 parts of cyclohexyl acrylate, 1-5 parts of cyclopentyl acrylate, 1-5 parts of cyclohexylmethyl acrylate, and 1-5 parts of dicyclopentadienyl acrylate.

6. The inkjet printing tape for power battery according to claim 4, characterized in that: The curing agent is selected from at least one of isocyanate curing agents, maleic anhydride curing agents, and melamine formaldehyde resin.

7. A method for preparing the inkjet coding tape for power batteries according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1 prepares an acrylic pressure-sensitive adhesive for standby use; S2 prepares UV light curing ink for standby use; S3 sprays UV light-curable ink onto the substrate layer and then light-cures it with a light intensity of 100-120mW / cm 2 ; S4 provides a release layer on a side of the substrate layer away from the ink layer; S5 extrusion-coating an acrylic pressure-sensitive adhesive on the cured ink layer; S6 is cured and rolled up to obtain a semi-finished adhesive tape.

8. The method for preparing the coding tape for power battery according to claim 7, characterized in that: The preparation method of the acrylic pressure-sensitive adhesive in step S1 is as follows: M1: Mix the acrylic acid monomers, introduce nitrogen, heat to 50-70°C under nitrogen protection, stir slowly for 5-7h, then add the initiator, continue the reaction for 4-6h to obtain a pre-reaction colloid; M2 is added with solvent I to dilute and stir the pre-reacted colloid. During the stirring process, a curing agent is added. After mixing evenly, a color paste is added and stirred evenly to obtain a pre-cured colloid. Solvent II and solvent III are continuously added to dilute the colloid to a coatable state and set aside.

9. The method for preparing the coding tape for power battery according to claim 7, characterized in that: The light curing time in step S3 is 10-50s.

10. The method for preparing the coding tape for power battery according to claim 7, characterized in that: The coating thickness of the acrylic pressure-sensitive adhesive in step S5 is 15-50 μm.

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