A fireproof insulating powder coating and its preparation method and application

Abstract

The present invention discloses a fireproof insulating powder coating and a preparation method and application thereof, and belongs to the technical field of coatings. The fireproof insulating powder coating provided by the present invention comprises the following raw materials in parts by mass: 50 to 250 parts of silicone modified epoxy resin, 50 to 250 epoxy resin, 1 to 60 parts of curing agent, 1 to 20 parts of accelerator, 100 to 300 parts of filler, and 50 to 350 parts of auxiliary agent; the curing agent comprises a modified dicyandiamide curing agent; the modified dicyandiamide curing agent contains at least one of an aromatic group, an amino group or an epoxy group. The modified dicyandiamide curing agent of the present invention has excellent flame retardant and heat resistant properties, and has good curing reaction activity with epoxy resin, which is beneficial to improving the fireproof and heat resistant properties of the coating; at the same time, by compounding it with silicone modified epoxy resin and epoxy resin, it can work together to obtain a powder coating with excellent fireproof and insulating properties, which has a wide range of applications in battery protection.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a fireproof insulating powder coating and a preparation method and application thereof. Background Art

[0002] After rapid development, the energy density of new energy vehicle batteries is getting higher and higher. At the same time, corresponding battery fast charging technology has emerged. When the vehicle is charging quickly, the on-board battery will accumulate a large amount of heat energy in a short period of time. If the battery management system or the heat dissipation system fails and the heat cannot be dissipated in time, it may damage the battery cell or even cause spontaneous combustion and explosion.

[0003] As the core energy source of new energy vehicles, the importance of battery packs is self-evident. Thermal runaway in the battery pack can cause a short circuit inside the battery pack, which can cause violent chemical reactions in the positive and negative electrode materials of the battery, leading to a sharp rise in the temperature of the battery cell, excessive pressure, shell rupture, spontaneous combustion of the vehicle, and even explosion. The spontaneous combustion of power batteries in electric vehicles has the characteristics of fast burning speed, high calorific value, large differences, and difficulty in extinguishing. At present, the fireproof materials of battery packs of various new energy vehicles are mainly laid with fireproof felt materials, but these materials are of high quality and large volume, which will increase the weight of the vehicle and affect the design and installation of battery cells. New energy vehicle companies need a material that is light in weight, easy to construct, and has excellent fireproof and insulation properties. Summary of the invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, one of the objects of the present invention is to provide a fire-proof insulating powder coating, which, in addition to having the excellent insulating properties of ordinary insulating powder coatings, also has excellent fire-proof properties, and can meet the needs of new energy vehicle companies for fire-proof materials in battery packs.

[0005] A second object of the present invention is to provide a method for preparing the above-mentioned fire-resistant insulating powder coating.

[0006] A third object of the present invention is to provide a fireproof insulating coating made from the above-mentioned fireproof insulating powder coating.

[0007] A fourth object of the present invention is to provide a method for preparing the above-mentioned fire-resistant insulating coating.

[0008] A fifth object of the present invention is to provide an application of the above-mentioned fireproof insulating powder coating or fireproof insulating coating in battery protection.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] The first aspect of the present invention provides a fireproof insulating powder coating, comprising the following raw materials in parts by weight: 50 to 250 parts of silicone-modified epoxy resin, 50 to 250 parts of epoxy resin, 1 to 60 parts of curing agent, 1 to 20 parts of accelerator, 100 to 300 parts of filler, and 50 to 350 parts of auxiliary agent; the curing agent comprises a modified dicyandiamide curing agent; the modified dicyandiamide curing agent contains at least one of an aromatic group, an amino group or an epoxy group.

[0011] The present invention uses high temperature resistant active groups such as aromatic, amino or epoxy groups to modify the dicyandiamide curing agent, which is beneficial to improving the flame retardant and heat resistance of the cured product. At the same time, the above-mentioned active groups can improve the solubility of the dicyandiamide curing agent in the epoxy resin, thereby improving the curing reaction activity of the dicyandiamide curing agent and the epoxy resin, and effectively improving the fireproof insulation performance of the coating. In addition, the present invention uses organic silicon modified epoxy resin and epoxy resin to compound, combined with the modified dicyandiamide curing agent after modification, and the fireproof insulation performance of the coating is improved together.

[0012] Preferably, the aromatic group contained in the modified dicyandiamide curing agent is a phenyl group or a benzyl group.

[0013] Preferably, in the powder coating, the epoxy equivalent of the silicone-modified epoxy resin is 200 to 900 g / eq.

[0014] In a specific embodiment of the present invention, in the powder coating, the organosilicon-modified epoxy resin includes at least one of JP-H26, ERS-Si1700, SAR-665 or ES-1001N.

[0015] Preferably, in the powder coating, the epoxy resin includes at least one of bisphenol A epoxy resin, novolac epoxy resin, phenoxy epoxy resin or acrylate epoxy resin.

[0016] Preferably, in the powder coating, the epoxy equivalent of the epoxy resin is 500 to 900 g / eq.

[0017] Preferably, in the powder coating, the amine equivalent of the modified dicyandiamide curing agent is 10 to 50 g / eq.

[0018] In a specific embodiment of the present invention, in the powder coating, the modified dicyandiamide curing agent includes at least one of FS-12 curing agent, JM-18 curing agent, PL-20 curing agent or ZK-125 curing agent.

[0019] Preferably, in the powder coating, the curing agent further comprises a hydrazide curing agent.

[0020] Amide curing agents can be combined with modified dicyandiamide curing agents to further improve the curing properties of silicone-modified epoxy resins and epoxy resins, and improve the fireproof and insulating properties of coatings.

[0021] Preferably, in the powder coating, the melting point of the hydrazide curing agent is 180-190°C.

[0022] Preferably, in the powder coating, the hydrazide curing agent includes at least one of succinic acid hydrazide, adipic acid dihydrazide, sebacic acid hydrazide or isophthalic acid hydrazide.

[0023] Preferably, in the powder coating, the curing agent includes 1 to 40 parts of modified dicyandiamide curing agent and 0 to 20 parts of hydrazide curing agent by mass; further preferably, the curing agent includes 1 to 35 parts of modified dicyandiamide curing agent and 1 to 20 parts of hydrazide curing agent by mass.

[0024] Preferably, in the powder coating, the filler includes at least one of calcium carbonate, aluminum hydroxide, mica powder or silica powder.

[0025] The calcium carbonate, aluminum hydroxide, mica powder or silicon powder used in the present invention as the functional filler in the powder coating can be matched with other raw materials to effectively improve the fireproof performance of the coating.

[0026] Preferably, in the powder coating, the accelerator is selected from imidazole accelerators; further preferably, the imidazole accelerator includes at least one of 2-methylimidazole, 2-phenylimidazole, 2-ethylimidazole or undecylimidazole.

[0027] Preferably, in the powder coating, the additives include an acid source, a carbon source and a gas source.

[0028] Using acid sources, carbon sources and gas sources as additives in the flame retardant system is beneficial to the thermal expansion of the coating to achieve a flame retardant effect and significantly improve the fire retardant performance of the coating.

[0029] Preferably, in the auxiliary agent, the acid source includes at least one of ammonium phosphate, carbonate or borate; further preferably, the auxiliary agent includes at least one of ammonium polyphosphate, ammonium bicarbonate or diamine hydrogen phosphate; further preferably, the acid source is selected from ammonium polyphosphate.

[0030] Preferably, in the acid source, the ammonium polyphosphate includes at least one of monoammonium phosphate, diammonium phosphate or triammonium phosphate; further preferably, the ammonium polyphosphate includes monoammonium phosphate, diammonium phosphate or a combination thereof.

[0031] Preferably, in the auxiliary agent, the carbon source includes at least one of pentaerythritol, dipentaerythritol, tetramethylenetetraol or sorbitol; further preferably, the carbon source is selected from pentaerythritol.

[0032] Preferably, in the auxiliary agent, the gas source includes at least one of dicyandiamide, melamine, glycine or urea; further preferably, the gas source is selected from melamine.

[0033] Preferably, in the powder coating, the additives include 20 to 100 parts of an acid source, 20 to 100 parts of a carbon source and 20 to 100 parts of a gas source, by weight; further preferably, the additives include 20 to 100 parts of ammonium polyphosphate, 20 to 100 parts of pentaerythritol and 20 to 100 parts of melamine, by weight.

[0034] The second aspect of the present invention provides a method for preparing the powder coating described in the first aspect of the present invention, comprising the following steps: mixing, melt-extruding and crushing the various preparation raw materials to obtain the powder coating.

[0035] Preferably, in the method for preparing the powder coating, the temperature of the melt extrusion is 80 to 100°C; more preferably, 90 to 95°C.

[0036] Preferably, in the method for preparing the powder coating, the pulverizing is performed to pulverize the powder until the particle size is 30 to 50 μm; more preferably, 35 to 45 μm.

[0037] In a specific embodiment of the present invention, in the method for preparing the powder coating, the melt extrusion is carried out in a twin-screw extruder.

[0038] The third aspect of the present invention provides a fireproof insulation coating made of the powder coating according to the first aspect of the present invention.

[0039] The fourth aspect of the present invention provides a method for preparing the fireproof insulating coating described in the third aspect of the present invention, comprising the following steps: coating the powder coating on a substrate, and obtaining the fireproof insulating coating after curing.

[0040] Preferably, in the method for preparing the coating, the powder coating is applied by spraying; more preferably, high-voltage electrostatic spraying.

[0041] Preferably, in the method for preparing the coating, the powder coating is cured by baking.

[0042] Preferably, in the method for preparing the coating, the curing temperature of the powder coating is 180-220°C; more preferably 190-210°C.

[0043] Preferably, in the method for preparing the coating, the curing time of the powder coating is 5 to 20 minutes; more preferably, it is 8 to 15 minutes.

[0044] Preferably, in the method for preparing the composite coating, the thickness of the powder coating is 120 to 400 μm; more preferably, 150 to 350 μm.

[0045] The fifth aspect of the present invention provides an application of the fireproof insulating powder coating described in the first aspect of the present invention, or the fireproof insulating coating described in the third aspect of the present invention in battery protection.

[0046] Furthermore, the battery is a battery for new energy equipment; further, the battery is a battery for a new energy vehicle.

[0047] The beneficial effects of the present invention are as follows: the modified dicyandiamide curing agent of the present invention has excellent flame retardant and heat resistant properties, and has good curing reaction activity with epoxy resin, which is beneficial to improving the fire retardant and heat resistant properties of the coating; at the same time, by compounding it with silicone-modified epoxy resin and epoxy resin, a powder coating with excellent fire retardant and insulating properties can be obtained, which has a wide application in battery protection.

[0048] Specifically, compared with the prior art, the present invention has the following advantages:

[0049] 1. The present invention further adopts an acid source, a carbon source and a gas source as auxiliary agents, which is beneficial to the thermal expansion of the coating to achieve a flame retardant effect and improve the fire retardant performance of the coating; and the calcium carbonate, aluminum hydroxide, mica powder or silicon powder used in the present invention as a functional filler in the powder coating can be combined with other raw materials to effectively improve the fire retardant performance of the coating; and the hydrazide curing agent and the organosilicon-modified epoxy resin themselves have excellent high temperature resistance. The reaction of the two, combined with the auxiliary agents containing acid sources, carbon sources and gas sources and the above-mentioned functional fillers, can obtain a powder coating with excellent high temperature resistance and fire retardant performance.

[0050] 2. The present invention utilizes epoxy resin to react with modified dicyandiamide curing agent and functional filler to improve the curing reaction activity, improve the electrical insulation effect of the cured product, and achieve excellent insulation performance of the powder coating.

[0051] 3. The powder coating preparation process of the present invention is simple, and a powder coating with integrated fireproof and insulating functions can be obtained by melt extrusion. The coating obtained by curing the powder coating also has excellent fireproof and insulating properties, and is widely used in battery protection. DETAILED DESCRIPTION

[0052] The content of the present invention is further described in detail below through specific examples. It should also be understood that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles set forth in the present invention all belong to the scope of protection of the present invention. The specific process parameters and the like in the following examples are also only examples within a suitable range, that is, those skilled in the art can make a selection within a suitable range through the description herein, and are not limited to the specific data exemplified below. The raw materials, reagents or devices used in the following examples and comparative examples, unless otherwise specified, can all be obtained from conventional commercial sources, or can be obtained by existing known methods.

[0053] It should be noted that the modified dicyandiamide curing agent used in the specific embodiment of the present invention includes at least one of FS-12 curing agent, JM-18 curing agent, PL-20 curing agent or ZK-125 curing agent. FS-12 curing agent was purchased from Kailuwei Chemical; JM-18 curing agent was purchased from Evonik of Germany; PL-20 curing agent was purchased from Yarui Chemical; ZK-125 curing agent was purchased from Belite Chemical.

[0054] Specifically, the FS-12 curing agent is obtained by modifying dicyandiamide with propylene oxide, propylene oxide butyl ether and epoxy resin, and the curing reaction activity is improved by increasing the compatibility of dicyandiamide with epoxy resin. The dicyandiamide modified with propylene oxide can be dissolved in EP in the presence of a small amount of acetone, and the reaction activity is greatly enhanced compared with the unmodified dicyandiamide.

[0055] JM-18 curing agent connects aniline to the molecular chain of dicyandiamide, destroying the regular structure and strong crystallinity of dicyandiamide itself, thereby improving the solubility of dicyandiamide in epoxy resin, and destroying the strong electron-withdrawing property of cyano group, releasing the activity of amino group. The introduction of active groups helps to enhance the curing activity.

[0056] The PL-20 curing agent uses propylene oxide-formaldehyde to modify dicyandiamide. The curing temperature of the system can be reduced by about 30°C, and it has a latent period of 2 months at room temperature. The introduction of a power supply group at the cyano group of dicyandiamide improves the activity of the hydrogen attached to the nitrogen, thereby increasing the activity of the curing reaction.

[0057] The ZK-125 curing agent uses dicyandiamide to prepolymerize liquefied dicyandiamide with butyl glycidyl ether (BGE), phenyl glycidyl ether (PGE) and benzyl glycidyl ether, thereby increasing the solubility of dicyandiamide in epoxy resin and ultimately achieving the purpose of improving its curing reaction activity.

[0058] The organosilicon-modified epoxy resin used in the specific embodiment of the present invention includes at least one of JP-H26, ERS-Si1700, SAR-665 or ES-1001N.

[0059] Compared with ordinary epoxy resin, the organosilicon modified epoxy resin used in the present invention has better fireproof insulation effect. In the specific implementation of the present invention, the filler used is a functional filler, including at least one of calcium carbonate, aluminum hydroxide, mica powder or silicon powder, wherein silicon powder, calcium carbonate, aluminum hydroxide, and mica powder are generally commercially available products. In the embodiment of the present invention, silicon powder uses Green New Material GB-4.

[0060] Example 1

[0061] A fireproof insulating powder coating is prepared from the following raw materials in parts by weight:

[0062]

[0063]

[0064] The epoxy equivalent of the JP-H26 silicone-modified epoxy resin is 760-900 g / eq; the epoxy equivalent of the phenolic epoxy resin is 500-720 g / eq; the amine equivalent of the FS-12 curing agent is 10-20 g / eq; the melting point of the sebacic acid hydrazide curing agent is 180-190° C.; the functional filler is silicon micropowder; the polyphosphate diammonium, melamine and pentaerythritol are all common products on the market; and the accelerator is undecyl imidazole.

[0065] The preparation method of the above powder coating comprises the following steps:

[0066] The above-mentioned raw materials are placed in a mixing tank according to the above-mentioned mass parts, fully mixed and crushed for 5 minutes to obtain a mixture, and then the obtained mixture is put into a twin-screw extruder for extrusion. The heating temperature of the extruder is controlled at 90-95°C, and then the mixture is tableted, cooled, and crushed into a powder with a particle size of 35-45μm to obtain the fire-retardant insulating powder coating.

[0067] Example 2

[0068] A fireproof insulating powder coating is prepared from the following raw materials in parts by weight:

[0069]

[0070] The epoxy equivalent of the ERS-Si1700 silicone-modified epoxy resin is 200-350 g / eq; the epoxy equivalent of the phenolic epoxy resin is 500-720 g / eq; the amine equivalent of the PL-20 curing agent is 20-28 g / eq; the melting point of the isophthalic acid hydrazide curing agent is 180-190° C.; the functional filler is aluminum hydroxide; the polyphosphate diammonium, melamine and pentaerythritol are all common products on the market; and the accelerator is 2-methylimidazole.

[0071] The preparation method of the above powder coating comprises the following steps:

[0072] The above-mentioned raw materials are placed in a mixing tank according to the above-mentioned mass parts, fully mixed and crushed for 5 minutes to obtain a mixture, and then the obtained mixture is put into a twin-screw extruder for extrusion. The heating temperature of the extruder is controlled at 90-95°C, and then the mixture is tableted, cooled, and crushed into a powder with a particle size of 35-45μm to obtain the fire-retardant insulating powder coating.

[0073] Example 3

[0074] A fireproof insulating powder coating is prepared from the following raw materials in parts by weight:

[0075]

[0076] The epoxy equivalent of the ES-1001N silicone-modified epoxy resin is 200-250 g / eq; the epoxy equivalent of the acrylate epoxy resin is 800-900 g / eq; the amine equivalent of the JM-18 curing agent is 30-35 g / eq; the melting point of the isophthalic acid hydrazide curing agent is 180-190° C.; the functional filler is mica powder; the polyphosphate diammonium, melamine and pentaerythritol are all common products on the market; and the accelerator is 2-methylimidazole.

[0077] The preparation method of the above powder coating comprises the following steps:

[0078] The above-mentioned raw materials are placed in a mixing tank according to the above-mentioned mass parts, fully mixed and crushed for 5 minutes to obtain a mixture, and then the obtained mixture is put into a twin-screw extruder for extrusion. The heating temperature of the extruder is controlled at 90-95°C, and then the mixture is tableted, cooled, and crushed into a powder with a particle size of 35-45μm to obtain the fire-retardant insulating powder coating.

[0079] Comparative Example 1

[0080] A powder coating, which differs from Example 1 in that an equal amount of common bisphenol A epoxy resin is used to replace the modified silicone epoxy resin, wherein the epoxy equivalent of the common bisphenol A epoxy resin is 340-600 g / eq. Other raw materials and preparation methods are the same as those in Example 1.

[0081] Comparative Example 2

[0082] A powder coating, which differs from Example 2 in that an equal amount of common bisphenol A epoxy resin is used to replace the novolac epoxy resin, wherein the epoxy equivalent of the common bisphenol A epoxy resin is 600-700 g / eq. Other raw materials and preparation methods are the same as those of Example 2.

[0083] Comparative Example 3

[0084] A powder coating, which differs from Example 3 in that an equal mass portion of common dicyandiamide curing agent is used to replace the modified dicyandiamide curing agent, wherein the amine equivalent of the common dicyandiamide curing agent is 30-35 g / eq. Other preparation raw materials and preparation methods are the same as those in Example 3.

[0085] Comparative Example 4

[0086] A powder coating, which differs from Example 1 in that an equal amount of ordinary barium sulfate filler is used to replace the silicon powder. Other raw materials and preparation methods are the same as those in Example 1.

[0087] Comparative Example 5

[0088] A powder coating, which differs from Example 2 in that the amount of the accelerator is changed to 0.5 parts. Other raw materials and preparation methods are the same as those in Example 2.

[0089] Comparative Example 6

[0090] A powder coating, which is different from Example 3 in that the amount of filler is changed to 250 parts. Other raw materials and preparation methods are the same as those in Example 3.

[0091] Application Examples

[0092] A fireproof insulating coating is prepared from the powder coatings described in Examples 1 to 3 and Comparative Examples 1 to 6. The specific preparation process is as follows:

[0093] The powder coatings described in Examples 1 to 3 and Comparative Examples 1 to 6 were sprayed on the workpiece by a high-voltage electrostatic spray gun and placed in a 200° C. oven for 10 minutes for curing to obtain the fireproof insulating coating, with a coating thickness of 150-350 μm.

[0094] Performance Testing

[0095] The coating obtained according to the corresponding case was subjected to relevant tests. The test content and standards are shown in Table 1, and the test results are shown in Table 2.

[0096] Table 1 Test items and standards

[0097]

[0098]

[0099] Table 2 Test results of coating

[0100]

[0101]

[0102] It can be seen from the above table that most properties of the coatings prepared by the powder coatings of Examples 1 to 3 are better than those of Comparative Examples 1 to 6, especially the fireproofing, heat insulation and voltage-resistant insulation properties are significantly better than those of Comparative Examples 1 to 6. The present invention provides an ideal powder coating integrating fireproofing and insulation functions, which can achieve good battery protection effect.

[0103] In the embodiment of the present invention, an acid source, a carbon source and a gas source are used as auxiliary agents, which is beneficial to the thermal expansion of the coating to achieve a flame retardant effect and improve the fire retardant performance of the coating; and the calcium carbonate, aluminum hydroxide, mica powder or silicon powder used in the embodiment as a functional filler in the powder coating can be combined with other raw materials to effectively improve the fire retardant performance of the coating; and the hydrazide curing agent and the silicone-modified epoxy resin themselves have excellent high temperature resistance. The reaction of the two, combined with the auxiliary agents containing acid sources, carbon sources and gas sources and the above-mentioned functional fillers, can obtain a powder coating with excellent high temperature resistance and fire retardant performance.

[0104] The embodiment of the present invention utilizes the reaction of epoxy resin with modified dicyandiamide curing agent and functional filler to improve the activity of curing reaction, improve the electrical insulation effect of the cured product, and achieve excellent insulation performance of the powder coating.

[0105] The powder coating of the present invention has a simple preparation process, and a powder coating with integrated fireproofing and insulating functions can be obtained by melt extrusion. The coating obtained by curing the powder coating also has excellent fireproofing and insulating properties, and is widely used in battery protection.

[0106] In summary, the modified dicyandiamide curing agent of the present invention has excellent flame retardant and heat resistant properties, and has good curing reaction activity with epoxy resin, which is beneficial to improving the fire retardant and heat resistant properties of the coating; at the same time, it can be compounded with silicone-modified epoxy resin and epoxy resin to jointly obtain a powder coating with excellent fire retardant and insulating properties, which has a wide range of applications in battery protection.

Claims

1. A fireproof insulating powder coating, characterized in that: The invention comprises the following raw materials in parts by weight: 50 to 250 parts of organosilicon-modified epoxy resin, 50 to 250 parts of epoxy resin, 1 to 60 parts of curing agent, 1 to 20 parts of accelerator, 100 to 150 parts of filler, and 50 to 350 parts of auxiliary agent; the curing agent comprises a modified dicyandiamide curing agent; the modified dicyandiamide curing agent contains at least one of an aromatic group, an amino group or an epoxy group; the curing agent also comprises a hydrazide curing agent; the hydrazide curing agent comprises at least one of succinic acid hydrazide, adipic acid dihydrazide, sebacic acid hydrazide or isophthalic acid hydrazide; The epoxy resin includes at least one of a phenolic epoxy resin, a phenoxy epoxy resin or an acrylate epoxy resin; The filler includes at least one of calcium carbonate, aluminum hydroxide, mica powder or silicon powder; The auxiliary agent includes an acid source, a carbon source and a gas source; the acid source includes at least one of ammonium phosphate, carbonate or borate; the carbon source includes at least one of pentaerythritol, dipentaerythritol, butanethritol or sorbitol; the gas source includes at least one of dicyandiamide, melamine, glycine or urea.

2. The powder coating according to claim 1, characterized in that The epoxy equivalent of the organosilicon-modified epoxy resin is 200 to 900 g / eq; And / or, the epoxy equivalent of the epoxy resin is 500 to 900 g / eq; And / or, the amine equivalent of the modified dicyandiamide curing agent is 10 to 50 g / eq.

3. The powder coating according to claim 1, characterized in that The melting point of the hydrazide curing agent is 180-190°C.

4. The powder coating according to claim 1, characterized in that The accelerator is selected from imidazole accelerators.

5. The method for preparing a powder coating according to any one of claims 1 to 4, characterized in that: The following steps are involved: The prepared raw materials are mixed, melt-extruded and crushed to obtain the powder coating.

6. A fireproof insulating coating, characterized in that: The invention is prepared from the powder coating according to any one of claims 1 to 4.

7. The method for preparing the fireproof insulating coating according to claim 6, characterized in that: The following steps are involved: The powder coating is coated on a substrate and cured to obtain the fireproof insulation coating.

8. Use of the fireproof insulating powder coating according to any one of claims 1 to 4 or the fireproof insulating coating according to claim 6 in battery protection.

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