High-shear uv flame retardant ink for insulation protection of battery cell and method of making same

Abstract

This invention discloses a high-shear UV flame-retardant ink for battery cell insulation protection, comprising, by weight, the following components: 5-20 parts of siloxane-modified phosphorus-nitrogen acrylate, 0.5-5 parts of phosphate acrylate, 5-15 parts of modified epoxy acrylate, 35-85 parts of reactive diluent, 1-10 parts of photoinitiator, 10-30 parts of thermally conductive filler, and 0.5-8 parts of colorant. The synthesized siloxane-modified phosphorus-nitrogen acrylate contains photocurable functional groups and siloxane groups, achieving a highly efficient halogen-free flame-retardant effect, giving the ink excellent flame-retardant and fire-resistant properties, and providing better battery safety. Simultaneously, it significantly improves the ink's adhesion to the battery cell substrate, thereby achieving high shear strength. This allows for rapid and efficient coating using UV inkjet printing technology to form a UV ink coating, which provides good thermal conductivity, extends battery life, provides superior safety, improves production efficiency, and reduces production costs.

Description

Technical Field

[0001] This invention relates to the field of ink technology, and in particular to a high-shear UV flame-retardant ink for battery cell insulation protection and its preparation method. Background Technology

[0002] With the continuous expansion of the new energy vehicle market, the power battery market is also showing a rapid growth trend. According to analysis data released by the South Korean market research institution SNE Research, global power battery sales reached 690 gigawatt-hours (GWh) in 2022, with the battery pack market size reaching US$125.5 billion, a year-on-year increase of 89%, more than quadrupling compared to 2020. As a core component of new energy vehicles, battery safety is crucial to the development of the entire industry. During use, to prevent battery short circuits, overcharging, and over-discharging, a blue protective film is generally used for wrapping and protection. Traditional blue protective films for battery cells are mostly acrylic-based tapes, with a shear strength of only 12 MPa at room temperature, which cannot meet the more demanding operating environments. Furthermore, the operating temperature range for battery cells is 40-60℃, and at higher temperatures, the blue film loses adhesion significantly, resulting in a substantial decrease in shear strength, making it impossible to guarantee safe use of the battery cells under these conditions. Secondly, the blue film coating solution has low production efficiency, requiring more time and manpower, leading to high overall costs. Moreover, the blue film is prone to bulging and other coating defects, resulting in a lower yield rate and further increasing costs. The application scope of blue film is relatively limited. Different molds and equipment are required for different types and specifications of batteries, resulting in higher costs. In addition, blue film has poor thermal conductivity and lacks fire resistance, which affects battery life and poses significant safety risks.

[0003] In view of the shortcomings of existing blue film coating technologies, this invention provides a UV ink that utilizes inkjet printing technology to achieve rapid and efficient coating, improving production efficiency and reducing production costs. This invention allows for customized coating on different types and specifications of batteries, with controllable thickness and high flexibility. Simultaneously, the UV ink possesses high shear strength, providing excellent protection for the battery cell. It also exhibits good flame-retardant and fire-resistant properties, excellent thermal conductivity, extending battery life and providing superior safety. Summary of the Invention

[0004] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide a high-shear UV flame-retardant ink for battery cell insulation protection. It adopts inkjet printing technology to achieve fast and efficient coating, improve production efficiency, reduce production costs, and the ink thickness is controllable, offering high flexibility. At the same time, the UV ink has high shear force, providing excellent protection for the battery cell. It also has good flame-retardant and fire-resistant properties, good thermal conductivity, which can extend the battery's lifespan and provide better safety.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-shear UV flame-retardant ink for battery cell insulation protection comprises, by weight, the following components: 5-20 parts of siloxane-modified phosphoric acid acrylate, 0.5-5 parts of phosphate acrylate, 5-15 parts of modified epoxy acrylate, 35-85 parts of reactive diluent, 1-10 parts of photoinitiator, 10-30 parts of thermally conductive filler, and 0.5-8 parts of colorant.

[0007] As a preferred embodiment, the siloxane-modified phosphoro-nitrogen acrylate is prepared by modifying hexachlorotriphosphazene and grafting a coupling agent, and its general formula is as follows:

[0008] ;

[0009] In the formula, R1 is a hydrogen atom or a methyl group; R2 is a methoxy or ethoxy group; m and n are both 1-6;

[0010] In the formula, -X-Si(R2)3 is a grafted coupling agent fragment, which is obtained by grafting an amino- or mercaptosiloxane-containing coupling agent.

[0011] As a preferred embodiment, the coupling agent is one or more of the following: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0012] As a preferred embodiment, the phosphate ester acrylate is one or more of the following: SR9050, SR9051, SR9053, CN2003, CN118 from Sartoma Chemical Company, PM-2 from Nippon Kayaku, and 6235, 6202, and 623A-80 from Changxing Chemical.

[0013] As a preferred embodiment, the modified epoxy acrylate is at least one of polyurethane modified epoxy acrylate, silicone modified epoxy acrylate, epoxy soybean oil modified acrylate, alicyclic epoxy modified acrylate, and modified phenolic epoxy acrylate.

[0014] As a preferred embodiment, the reactive diluent is one or a combination of several of the following: glycidyl methacrylate, isobornyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 2-phenoxyethyl methacrylate, trimethylolpropane formal acrylate, tetrahydrofuran methacrylate, alkyloxytetrahydrofuran acrylate, alkyloxyphenol acrylate, ethoxynonylphenol acrylate, caprolactone methacrylate, isooctyl acrylate, dodecyl methacrylate, isodecanyl methacrylate, caprolactone methacrylate, hydroxyethyl methacrylate; dicyclopentyl methacrylate, dioxanediol diacrylate, dimethacrylate, hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, or dipentaerythritol hexaacrylate.

[0015] As a preferred embodiment, the photoinitiator is a combination of one or both of a cleavage initiator and a hydrogen abstraction initiator. The cleavage initiator is selected from 1173, 184, 907, 2022, 369, 1490, 819, TPO, TPO-L, TMO, or MBF. The hydrogen abstraction initiator is a combination of benzophenone and 2-isopropylthioxanthrone.

[0016] As a preferred embodiment, the thermally conductive filler is any one or a mixture of several of the following: alumina, aluminum nitride, boron nitride, silicon carbide, zinc oxide, and silicon micro powder, and the particle size of the thermally conductive filler is less than 10 μm; the color paste is a UV nano color paste.

[0017] As a preferred embodiment, the particle size of the thermally conductive filler is less than 1 μm.

[0018] A method for preparing a high-shear UV flame-retardant ink for battery cell insulation protection involves adding the aforementioned components to a mixing tank in proportion, stirring for 30-60 minutes, mixing evenly, grinding with a sand mill for 2-3 hours, then dispersing with a high-speed disperser for 1-2 hours, and finally filtering to obtain the high-shear UV flame-retardant ink for battery cell insulation protection.

[0019] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution:

[0020] The synthesized siloxane-modified phosphorus-nitrogen acrylate, containing photocurable functional groups and siloxane groups, serves as a key material for high-shear UV inks for battery cell insulation protection. This results in highly efficient halogen-free flame retardancy, giving the ink excellent flame-retardant and fire-resistant properties, thus providing better battery safety. Simultaneously, it significantly enhances the ink's adhesion to the battery cell substrate, achieving high shear strength. This allows for rapid and efficient UV ink coating using UV inkjet printing technology. This UV ink coating provides excellent thermal conductivity, extending battery life and providing superior safety, while improving production efficiency and reducing production costs. Furthermore, it enables customized coating on different types and specifications of batteries, with controllable thickness and high flexibility.

[0021] To more clearly illustrate the effects of the present invention, the present invention will be described in detail below with reference to specific embodiments. Detailed Implementation

[0022] This invention discloses a high-shear UV flame-retardant ink for battery cell insulation protection, comprising the following components by weight: 5-20 parts of siloxane-modified phosphoric acid acrylate, 0.5-5 parts of phosphate acrylate, 5-15 parts of modified epoxy acrylate, 35-85 parts of reactive diluent, 1-10 parts of photoinitiator, 10-30 parts of thermally conductive filler, and 0.5-8 parts of colorant.

[0023] The siloxane-modified phosphoro-nitrogen acrylate is prepared by modifying hexachlorotriphosphazene and grafting a coupling agent, and its general formula is as follows:

[0024] ;

[0025] In the formula, R1 is a hydrogen atom or a methyl group; R2 is a methoxy or ethoxy group; m and n are both 1-6;

[0026] In the formula, -X-Si(R2)3 is a grafted coupling agent fragment, which is obtained by grafting an amino- or mercaptosiloxane-containing coupling agent. In addition, the coupling agent used is one or more of the following: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

[0027] The phosphate ester acrylate is one or more of the following: SR9050, SR9051, SR9053, CN2003, CN118 from Sartoma Chemical Company, PM-2 from Nippon Kayaku, and 6235, 6202, and 623A-80 from Changxing Chemical.

[0028] The modified epoxy acrylate is at least one of polyurethane modified epoxy acrylate, silicone modified epoxy acrylate, epoxy soybean oil modified acrylate, alicyclic epoxy modified acrylate, and modified phenolic epoxy acrylate.

[0029] The active diluent is one or a combination of several of the following: glycidyl methacrylate, isobornyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 2-phenoxyethyl methacrylate, trimethylolpropane formal acrylate, tetrahydrofuran methacrylate, alkyloxytetrahydrofuran acrylate, alkyloxyphenol acrylate, ethoxynonylphenol acrylate, caprolactone methacrylate, isooctyl acrylate, dodecyl methacrylate, isodecanyl methacrylate, caprolactone methacrylate, hydroxyethyl methacrylate; dicyclopentyl methacrylate, dioxanediol diacrylate, dimethacrylate, hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, or dipentaerythritol hexaacrylate.

[0030] The photoinitiator is a combination of one or two of the following: a cleavage initiator and a hydrogen abstraction initiator. The cleavage initiator is selected from 1173, 184, 907, 2022, 369, 1490, 819, TPO, TPO-L, TMO, or MBF. The hydrogen abstraction initiator is a combination of benzophenone and 2-isopropylthioxanthrone.

[0031] The thermally conductive filler is any one or a mixture of several of the following: alumina, aluminum nitride, boron nitride, silicon carbide, zinc oxide, and silicon micro powder. The particle size of the thermally conductive filler is less than 10 μm. Specifically, a particle size of less than 1 μm can achieve better results. The color paste is a UV nano color paste, which is formed by ultrafine dispersion of organic or inorganic pigments in the aforementioned reactive diluent.

[0032] This invention also discloses a method for preparing a high-shear UV flame-retardant ink for battery cell insulation protection. The aforementioned components are added to a mixing tank in proportion and stirred for 30-60 minutes. After mixing evenly, the mixture is ground in a sand mill for 2-3 hours, then dispersed in a high-speed disperser for 1-2 hours, and finally filtered to obtain the high-shear UV flame-retardant ink for battery cell insulation protection.

[0033] The following detailed description is based on specific embodiments.

[0034] Example 1

[0035] The percentage content of each component by weight is as follows:

[0036]

[0037] The siloxane-modified phosphoro-nitrogen acrylate, model HCPSi-1, is a self-made siloxane-modified phosphoro-nitrogen acrylate. In a 500ml three-necked flask equipped with an electromagnetic stirrer, reflux condenser, and nitrogen inlet, 17.4g HEA, 38.3g N-phenyl-3-aminopropyltrimethoxysilane, 30.4g Et3N, 0.1g CuCl, and 150ml THF were added. Under ice bath conditions, 100ml of THF solution was added dropwise, wherein the aforementioned THF solution contained 17.4g hexachlorotriphosphazene. The reaction system was stirred at 60℃ under a N2 atmosphere for 48h. The white triethylamine hydrochloride precipitate was removed by filtration, and the product obtained by removing THF under reduced pressure was HCPSi-1.

[0038] Example 2

[0039] The percentage content of each component by weight is as follows:

[0040]

[0041] The siloxane-modified phosphoro-nitrogen acrylate, model HCPSi-2, is a self-made siloxane-modified phosphoro-nitrogen acrylate. In a 500ml three-necked flask equipped with an electromagnetic stirrer, reflux condenser, and nitrogen inlet, 27.3g HEA, 7.7g HEMA, 10.6g 3-mercaptopropylmethyldimethoxysilane, 35.7g Et3N, 0.1g CuCl, and 150ml THF were added. Under ice bath conditions, 150ml of THF solution was added dropwise, wherein the aforementioned THF solution contained 20.5g hexachlorotriphosphazene. The reaction system was stirred at 60℃ under a N2 atmosphere for 48h. The white triethylamine hydrochloride precipitate was removed by filtration, and the product obtained by removing THF under reduced pressure was HCPSi-2.

[0042] Example 3

[0043] The percentage content of each component by weight is as follows:

[0044]

[0045] The siloxane-modified phosphoro-nitrogen acrylate, model HCPSi-3, is a self-made siloxane-modified phosphoro-nitrogen acrylate. In a 500ml three-necked flask equipped with an electromagnetic stirrer, reflux condenser, and nitrogen inlet, 28.9g HEMA, 21.8g 3-mercaptopropyltrimethoxysilane, 33.7g Et3N, 0.1g CuCl, and 150ml THF were added. Under ice bath conditions, 150ml of THF solution, containing 19.3g hexachlorotriphosphazene, was added dropwise. The reaction system was stirred at 60℃ under N2 atmosphere for 48h. The white triethylamine hydrochloride precipitate was removed by filtration, and the product obtained by removing THF under reduced pressure was HCPSi-3.

[0046] Example 4

[0047] The percentage content of each component by weight is as follows:

[0048]

[0049] Example 5

[0050] The percentage content of each component by weight is as follows:

[0051]

[0052] Example 6

[0053] The percentage content of each component by weight is as follows:

[0054]

[0055] Comparative Example 1

[0056] Traditional blue film.

[0057] The UV inks prepared in the above embodiments and the comparative examples were subjected to performance tests, and the results are shown in the table below.

[0058]

[0059] The performance test data in the table above is explained as follows:

[0060] This invention utilizes siloxane-modified phosphorus-nitrogen acrylate as a key material to prepare a high-shear UV ink for battery cell insulation protection. This ink exhibits excellent adhesion and significantly superior shear strength compared to traditional blue films, especially retaining high shear strength even at high temperatures—a feat unmatched by traditional blue films. The ink also possesses good insulation properties and thermal conductivity far exceeding that of traditional blue films, while achieving a V-0 flame retardant rating, thus providing better battery safety.

[0061] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the technical scope of the present invention. Therefore, any minor modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A high-shear UV flame-retardant ink for battery cell insulation protection, characterized in that: By weight, it comprises the following components: 5-20 parts of siloxane-modified phosphorus-nitrogen acrylate, 0.5-5 parts of phosphate acrylate, 5-15 parts of modified epoxy acrylate, 35-85 parts of reactive diluent, 1-10 parts of photoinitiator, 10-30 parts of thermally conductive filler, and 0.5-8 parts of color paste; wherein, the siloxane-modified phosphorus-nitrogen acrylate is prepared by modifying hexachlorotriphosphazene and grafting a coupling agent, and its general formula is as follows: ； In the formula, R1 is a hydrogen atom or a methyl group; R2 is a methoxy or ethoxy group; m and n are both 1-6; In the formula, -X-Si(R2)3 is a grafted coupling agent fragment, which is obtained by grafting an amino- or mercaptosiloxane-containing coupling agent.

2. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The coupling agent is one or more of the following: N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

3. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The phosphate ester acrylate is one or more of the following: SR9050, SR9051, SR9053, CN2003, CN118 from Sartoma Chemical Company, PM-2 from Nippon Kayaku, and 6235, 6202, and 623A-80 from Changxing Chemical.

4. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The modified epoxy acrylate is at least one of polyurethane modified epoxy acrylate, silicone modified epoxy acrylate, epoxy soybean oil modified acrylate, alicyclic epoxy modified acrylate, and modified phenolic epoxy acrylate.

5. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The active diluent is one or a combination of several of the following: glycidyl methacrylate, isobornyl methacrylate, 3,4-epoxycyclohexyl methacrylate, 2-phenoxyethyl methacrylate, trimethylolpropane formal acrylate, tetrahydrofuran methacrylate, alkyloxytetrahydrofuran acrylate, alkyloxyphenol acrylate, ethoxynonylphenol acrylate, caprolactone methacrylate, isooctyl acrylate, dodecyl methacrylate, isodecanyl methacrylate, caprolactone methacrylate, hydroxyethyl methacrylate; dicyclopentyl methacrylate, dioxanediol diacrylate, dimethacrylate, hexanediol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, or dipentaerythritol hexaacrylate.

6. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The photoinitiator is a combination of one or two of the following: a cleavage initiator and a hydrogen abstraction initiator. The cleavage initiator is selected from 1173, 184, 907, 2022, 369, 1490, 819, TPO, TPO-L, TMO, or MBF. The hydrogen abstraction initiator is a combination of benzophenone and 2-isopropylthioxanthrone.

7. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The thermally conductive filler is any one or a mixture of several of the following: alumina, aluminum nitride, boron nitride, silicon carbide, zinc oxide, and silicon micro powder, and the particle size of the thermally conductive filler is less than 10 μm; the color paste is a UV nano color paste.

8. The high-shear UV flame-retardant ink for cell insulation protection according to claim 1, characterized in that: The particle size of the thermally conductive filler is less than 1 μm.

9. A method for preparing a high-shear UV flame-retardant ink for battery cell insulation protection, characterized in that: Add each component of any one of claims 1-8 to a mixing tank in proportion, stir for 30-60 minutes, mix evenly, then grind with a sand mill for 2-3 hours, then disperse with a high-speed disperser for 1-2 hours, and then filter to obtain a high-shear UV flame-retardant ink for battery cell insulation protection.

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