Fireproof composites for electric vehicle batteries made of liquid applied coatings and mats or felts

Abstract

The present invention relates to a fire protection composite material made of liquid applied coatings and mats or felts; a method for preparing the fire protection composite material; the use of the fireproof composite material for an electric vehicle battery; an electric vehicle battery comprising the fireproof composite material; the invention also provides a preparation method of the electric vehicle battery.

Description

Technical Field

[0001] The present invention relates to a fire-resistant composite material made of a liquid applied coating and a mat or fleece that can be used in electric vehicle batteries. Technical Background

[0002] In recent years, the number of electric vehicles has continued to increase. Batteries are the main source of power for electric vehicles. As battery energy density increases, the fire resistance and heat insulation performance of batteries need to be further improved to protect the safety of passengers in the vehicle.

[0003] However, all available battery fire protection products either lack adequate fire and thermal insulation properties or suffer from mechanical stability and electrical insulation issues, especially in thermal runaway scenarios.

[0004] Therefore, there is a need for a fire-resistant composite material that exhibits improvements in fire protection, thermal insulation properties and mechanical stability. Summary of the Invention

[0005] The present invention provides a fire-resistant composite material made from a liquid-applied coating and a mat or felt.

[0006] The present invention also provides a method for preparing a fire-resistant composite material according to the present invention, comprising applying a liquid-applied coating according to the present invention to a substrate; subsequently placing a pad or felt according to the present invention on the coating; if necessary, applying a further liquid-applied coating according to the present invention to the pad or felt; and drying the coating at room temperature or at an elevated temperature.

[0007] The present invention also provides use of the fireproof composite material according to the present invention for an electric vehicle battery, and preferably for a battery housing in an electric vehicle.

[0008] In addition, the present invention also provides an electric vehicle battery containing the fireproof composite material of the present invention.

[0009] In addition, the present invention also provides a method for preparing the electric vehicle battery of the present invention, comprising: preparing the fireproof composite material on the cover and / or shell of the electric vehicle battery according to the preparation method of the fireproof composite material of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The adhesion of the mat in the fire-resistant composite material according to the present invention on the paint is shown.

[0011] FIG2 shows the wettability of a liquid applied fire retardant coating on a mat in a fire retardant composite material according to the present invention, wherein Figure 2a The picture corresponds to Example 4, and Figure 2b The picture corresponds to Example 3.

[0012] Figure 3 Describes the test methods used to determine the ability of fire-resistant composite materials to resist heat and fire for a specified period of time.

[0013] Figure 4 Comparative test results of heat resistance and flame retardancy between the composite material according to the present invention and a control electroplated coated steel substrate are shown.

[0014] Figure 5 shows the control electroplated coated steel substrate ( Figure 5a ) and the fireproof composite material according to the present invention ( Figure 5b ) pictures. Detailed Description of the Invention

[0016] The present invention will be described in more detail below. Unless otherwise explicitly stated, each aspect described herein can be combined with any one or more other aspects. Specifically, any feature described as preferred or advantageous can be combined with any other one or more features described as preferred or advantageous.

[0017] In the context of the present invention, the terms used are to be interpreted according to the following definitions, unless the context dictates otherwise.

[0018] As used herein, the singular forms "a," "an," and "the" include singular and plural referents unless the context clearly dictates otherwise.

[0019] As used herein, the term "comprising" is synonymous with "including" or "containing" and is inclusive or open-ended and does not exclude additional, unrecited members, elements, or method steps.

[0020] As used herein, the term "consisting of excludes any unspecified element, ingredient, member, or method step.

[0021] The words "preferred," "preferably," "desirably," and "particularly" are frequently used herein to refer to examples in which embodiments of the present disclosure may provide particular benefits under particular circumstances. However, the listing of one or more preferred, preferred, desired, or particular embodiments does not imply that other embodiments are not useful, nor is it intended to exclude such other embodiments from the scope of the present disclosure.

[0022] Throughout this application, the word "may" is used in a permissive sense—that is, having the potential—rather than a mandatory sense.

[0023] The recitation of numerical endpoints includes all numbers and fractions within the corresponding range, as well as the recited endpoints.

[0024] Unless otherwise indicated, all percentages, parts, ratios, etc. mentioned herein are by weight.

[0025] When an amount, concentration or other value or parameter is expressed in the form of a range, a preferred range, a preferred upper value and a preferred lower value, it should be understood that any range resulting from the combination of any upper value or preferred value with any lower value or preferred value is specifically disclosed, regardless of whether the resulting range is explicitly mentioned in the context.

[0026] As used herein, the term "one-part (1K) composition" refers to a composition in which the components of the composition are all mixed together during storage of the composition, but the properties of the composition, including viscosity, remain sufficiently consistent during storage to allow the composition to be successfully utilized at a later time.

[0027] A "two-component (2K) composition" is understood to be a composition in which the first and second components / parts must be stored in separate containers due to their (high) reactivity. The two components / parts are mixed only shortly before application and then react (usually without additional activation) to form bonds and thus the polymer network. Higher temperatures can be applied to accelerate the crosslinking reaction.

[0028] The term "battery" as used herein may refer to a variety of different battery chemistries and configurations, including but not limited to lithium-ion (e.g., lithium iron phosphate, lithium cobalt oxide, other lithium metal oxides, etc.), lithium-ion polymer, nickel metal hydride, nickel cadmium, nickel metal hydride, nickel zinc, silver zinc, or other battery types / configurations.

[0029] As used herein, the term "electric vehicle" may refer to a fully electric vehicle (also known as an EV), a plug-in hybrid vehicle (also known as a PHEV), or a hybrid vehicle (also known as an HEV), where a hybrid vehicle refers to a vehicle that utilizes multiple propulsion sources, one of which is an electric drive system.

[0030] All references cited in this specification are incorporated by reference in their entirety.

[0031] Unless otherwise defined, all terms used in the disclosure of the present invention, including technical and scientific terms, have the meanings commonly understood by those skilled in the art to which the present invention belongs. For further guidance, term definitions are included herein to better understand the teachings of the present invention.

[0032] Fire-resistant composite materials

[0033] The present invention relates to a fire resistant composite material made from a liquid applied coating and a mat or felt.

[0034] Surprisingly, the inventors have found that the fire-resistant composite materials according to the invention show a significant improvement in fire protection, thermal insulation behaviour and / or mechanical stability compared to the prior art.

[0035] The thickness of the composite material is preferably 0.2 to 4 mm, more preferably 0.5 to 2 mm. When the thickness of the composite material is within the above range, an optimal balance can be achieved between the layer thickness required for sufficient fire protection and the minimum layer thickness required to save battery system installation space, depending on the battery design.

[0036] As used herein, all thicknesses are measured using calipers and / or ultrasonic thickness measuring devices.

[0037] Liquid applied coatings

[0038] As used herein, "liquid-applied coating" refers to a coating whose components are partially or entirely liquid upon application (preferably at 5 to 80°C) and which can be hardened by crosslinking or solvent evaporation. The viscosity of the coating is not particularly limited; however, when the coating is epoxy-based, its viscosity is preferably 15 to 30 Pa·s at 25°C; when the coating is water-based, its viscosity is preferably 10 to 1000 Pa·s at 25°C.

[0039] As used herein, all viscosities are measured using a Brookfield viscometer (spindle 27) at 25°C.

[0040] Preferably, the liquid-applied coating according to the present invention is a two-component epoxy-based intumescent material and / or a one-component water-based material containing inorganic fillers and / or fibers. When the coating is a two-component epoxy-based intumescent material and / or a one-component water-based material containing inorganic fillers and / or fibers, the compatibility of the coating with the mat or felt is improved, thereby further enhancing the adhesion and mechanical stability of the fire-resistant composite material according to the present invention.

[0041] In a preferred embodiment of the present invention, the two-component epoxy-based intumescent material comprises:

[0042] The first part contains

[0043] 1) epoxy resin; and

[0044] 2) flame retardant compounds; and

[0045] The second part contains

[0046] 1) a first amine comprising N,N'-bis(3-aminopropyl)ethylenediamine and 3,3'-oxybis(ethyleneoxy)bis(propylamine);

[0047] 2) a second amine comprising meta-xylylenediamine and a polymer of formaldehyde with 1,3-xylylenediamine and phenol; and

[0048] 3) Flame retardant compounds.

[0049] When the above-mentioned two-component epoxy-based intumescent material is used as the coating of the present invention, it can be applied to two-dimensional components (such as battery covers) by advection, which means that it does not require masking because there is no splashing and no aerosol formation; and a thin initial layer thickness can be applied, which saves installation space and still provides good thermal protection due to the expansion reaction.

[0050] In another preferred embodiment of the present invention, the one-component water-based material containing inorganic fillers and / or fibers is a non-reactive water-based dispersion containing an acrylic binder, glass fibers, and a flame retardant component.

[0051] When the above-mentioned one-component water-based material containing inorganic fillers and / or fibers is used as the coating of the present invention, water is used as an environmentally compatible and health-friendly solvent, the one-component material has advantages in terms of equipment procurement, does not form flames or smoke when exposed to heat / flame, and does not cause chemical reactions in the battery system, and according to the design, it does not block the ventilation channels because the thermal protection is formed by the thickness of the layer initially applied.

[0052] The two-component epoxy-based intumescent material according to the present invention comprises an epoxy resin. The epoxy resin is present in the first part of the composition.

[0053] Preferably, the epoxy resin is selected from epoxy resins based on bisphenol A and epichlorohydrin, bisphenol A diglycidyl ether epoxy resins, bisphenol F diglycidyl ether epoxy resins, cresol novolac epoxy resins, C4-28 alkylene diglycidyl ethers, C2-28 alkylene and / or alkenylene diglycidyl esters, C2-28 alkylene monophenol glycidyl ethers, C2-28 alkylene polyphenol glycidyl ethers; polyglycidyl ethers of the following compounds: trimethylolpropane, catechol, resorcinol, hydroquinone, 4,4',4"-trihydroxyphenylmethane, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxy-3,3'-dimethyldiphenylmethane, phenylmethane, 4,4'-dihydroxydiphenyldimethylmethane, 4,4'-dihydroxydiphenylmethylmethane, 4,4'-dihydroxydiphenylcyclohexane, 4,4'-dihydroxy-3,3'-dimethyldiphenylpropane, 4,4'-dihydroxydiphenylsulfone or tris(4-hydroxyphenyl)methane; methylenebis(naphthalene)diol, methylenebis(naphthalene)triol or methylenebis(naphthalene)tetrol, 2,7,2',7'-tetraglycidyloxynaphthalenemethane and / or 1,1,2,2-tetra(4-glycidyloxyphenyl)ethane, cresol novolac epoxy resin sorbitol glycidyl ether and mixtures thereof, more preferably epoxy resins based on bisphenol A and epichlorohydrin.

[0054] The above epoxy resins are preferred, and epoxy resins based on bisphenol A and epichlorohydrin are particularly preferred because they are flame retardant when exposed to flame in a flame test.

[0055] Commercially available epoxy resins suitable for use in the present invention include, but are not limited to, DER 331 from Olin.

[0056] The two-component epoxy-based intumescent material according to the present invention may have 30 to 60 wt%, preferably 35 to 50 wt%, and more preferably 38 to 42 wt% of epoxy resin based on the total weight of the first part of the composition.

[0057] The above ranges are preferred because they provide the composition with optimal heat and flame retardant behavior as well as rheological behavior.

[0058] The two-component epoxy-based intumescent material according to the present invention comprises a combination of a first amine and a second amine. The first amine and the second amine are present in the second part of the composition.

[0059] In one embodiment, the first amine comprises a mixture of N,N'-bis(3-aminopropyl)ethylenediamine and 3,3'-oxybis(ethyleneoxy)bis(propylamine), and the second amine comprises a mixture of m-xylylenediamine and a polymer of formaldehyde with 1,3-xylylenediamine and phenol.

[0060] In one embodiment, the first amine consists of a mixture of N,N'-bis(3-aminopropyl)ethylenediamine and 3,3'-oxybis(ethyleneoxy)bis(propylamine), and the second amine consists of a mixture of m-xylylenediamine and a polymer of formaldehyde with 1,3-xylylenediamine and phenol.

[0061] In another embodiment, the first amine is poly(propylene glycol) bis(2-aminopropyl ether) (CAS 9046-10-0) and the second amine is 5-amino-1,3,3-trimethylcyclohexanemethylamine (CAS 2855-16-2).

[0062] The mixture of the first amine and the second amine is selected and used because it shows good flame resistance when exposed to flame in the flame test. In addition, the applicant has found that the use of the combination of the first amine and the second amine can control the crosslinking speed and increase the crosslinking speed.

[0063] The two-component epoxy-based intumescent material according to the present invention may have the first amine and the second amine present in a ratio of 60:40 to 99:1.

[0064] The preferred ratio is 60:40 to 99:1 because the reaction rate depends on the amount of the second amine. If the ratio of the second amine is too high, it may cause the reaction to be too fast, thereby adversely affecting the application process.

[0065] Commercially available first amines suitable for use in the present invention include, but are not limited to, Ancamine 2432 from Evonik. Commercially available second amines suitable for use in the present invention include, but are not limited to, Ancamine 2914UF from Evonik.

[0066] The two-component epoxy-based intumescent material according to the present invention may have the first amine and the second amine in the second part of the composition, accounting for 30 to 50 wt %, preferably 38 to 48 wt %, more preferably 43 to 47 wt % of the total weight of the second part of the composition.

[0067] The above range is based on the amount of epoxy resin in the first part and is preferred because it can result in complete reaction with no unreacted epoxy resin in the composition.

[0068] The one-component water-based material of the present invention comprises a (meth)acrylic resin. Preferably, the resin is an acrylic resin.

[0069] The (meth)acrylic resin used in the present invention may be linear or branched, and may be composed of copolymerized alkyl-functional (meth)acrylic monomers, acid-functional (meth)acrylic monomers, tertiary amine-functional (meth)acrylic monomers, and may contain other functional groups.

[0070] Branching of the (meth)acrylic resin can be induced by copolymerizing polyfunctional comonomers and / or using polyfunctional chain transfer agents and / or polyfunctional initiators.

[0071] Suitable comonomers for forming the (meth)acrylic resins of the present invention include C1 to C12 esters of methacrylic acid and acrylic acid, including but not limited to methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, dodecyl (lauryl) methacrylate, or the corresponding acrylates. Mixtures of compatible (meth)acrylate monomers may also be used. Methacrylic and acrylic comonomers based on esters of methacrylic acid and acrylic acid with polyethylene glycol and / or polypropylene glycol and / or glycol ethers may also be used. Other useful vinyl comonomers include vinyl esters (e.g., vinyl acetate and vinyl propionate); vinyl ethers; esters of crotonic acid, maleic acid, fumaric acid, and itaconic acid; styrene; alkyl styrenes; acrylonitrile; butadiene, and the like, and comonomers thereof. The specific monomers selected will depend largely on the intended end use of the adhesive.

[0072] Suitable acid-functional comonomers for use in forming the (meth)acrylic resins of the present invention include, but are not limited to, methacrylic acid and acrylic acid.

[0073] Suitable hydroxyl-functional comonomers that may be added to form the (meth)acrylic resins of the present invention include, but are not limited to, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate or the corresponding acrylates.

[0074] Suitable amine-functional comonomers for use in forming the (meth)acrylic resins of the present invention include, but are not limited to, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, or the corresponding acrylates.

[0075] (Meth)acrylic resins can be prepared by free radical polymerization, and their molecular weight (Mn) can be controlled by using chain transfer agents (e.g., mercaptans such as dodecyl mercaptan or catalytic chain transfer agents based on transition metal complexes). Branched (meth)acrylic resins can be prepared by copolymerizing multifunctional monomers and / or using multifunctional chain transfer agents and / or multifunctional initiators.

[0076] Commercially available acrylic resins suitable for use in the present invention include, but are not limited to, Acronal DS 3502 from BASF.

[0077] The one-component water-based material according to the present invention may have 6 to 30 wt %, preferably 8 to 25 wt %, more preferably 10 to 20 wt % of the acrylic resin based on the total weight of the first part of the composition.

[0078] The above ranges are preferred because they provide the composition with optimal heat and flame retardant behavior as well as rheological behavior.

[0079] The one-component water-based material according to the present invention comprises glass fibers.

[0080] Commercially available glass fibers suitable for use in the present invention include, but are not limited to, Saint-Gobain Vetrotex's Faser Glass 4.5 mm.

[0081] The one-component water-based material according to the present invention may have 0.1 to 5 wt%, more preferably 0.2 to 3 wt% and even more preferably 0.3 to 1.5 wt% of glass fibers, based on the total weight of the composition.

[0082] The one-component water-based material according to the present invention contains water.

[0083] The one-component water-based material according to the present invention may contain 15 to 45 wt %, more preferably 20 to 40 wt %, even more preferably 25 to 35 wt % of water based on the total weight of the composition.

[0084] The two-component epoxy-based intumescent material and the one-component water-based material according to the present invention contain a flame retardant compound.

[0085] The flame retardant compound may be present in the first part of the composition and / or the second part of the composition in a two-component composition and may be the same or different in the first and second parts of the composition.

[0086] The flame retardant compound is independently selected from aluminum trihydroxide, aluminum hydroxide, mica, calcium carbonate, arsenic oxide, expanded graphite, calcium sulfate, cyanuric acid derivatives, cresyl diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, tris(isopropylated phenyl) phosphate, tris(xylyl) phosphate, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate, decyl diphenyl phosphate, tris(2-chloroethyl) phosphate, tris(2-chloropropyl) phosphate, tris(2,3-dibromopropyl) phosphate, tetrakis(2-chloro)-ethylene diphosphate, dimethyl methylphosphonate, diethyl ethylphosphonate, chlorinated paraffin, hexabromobenzene, brominated diphenyl ether, dibromoneopentyl glycol, monopentaerythritol, dipentaerythritol, coated red phosphorus and mixtures thereof, preferably the group consisting of cresyl diphenyl phosphate, calcium carbonate, mica, aluminum trihydroxide, aluminum hydroxide, ammonium polyphosphate and mixtures thereof.

[0087] The preferred flame retardant compounds mentioned above are preferred because they allow the composition according to the invention to be applied as a thin and light layer of protective coating, which reduces the spread of temperature and provides flame retardant and thermal insulation properties.

[0088] Commercially available flame retardant compounds suitable for use in the present invention include, but are not limited to, Omya BLH from Omya and Disflamoll DPK from Lanxess.

[0089] The two-component epoxy-based intumescent material according to the present invention may have the flame retardant compound present in the first part in an amount of 35 to 65 wt%, preferably 45 to 60 wt%, more preferably 51 to 57 wt%, based on the total weight of the first part of the composition.

[0090] The two-component epoxy-based intumescent material according to the present invention may have the flame retardant compound present in the second part in an amount of 20 to 65 wt%, preferably 50 to 60 wt%, more preferably 51 to 57 wt% based on the total weight of the second part of the composition.

[0091] The one-component water-based material according to the present invention may have 30 to 65 wt %, preferably 35 to 60 wt %, more preferably 38 to 55 wt % of the flame retardant compound based on the total weight of the composition.

[0092] The above range provides the composition with good viscosity and good mixing properties. In particular, if the content of the flame retardant compound is too low, it may adversely affect heat dissipation properties, and the composition may also become free-flowing and difficult to mix. On the other hand, if the content is too high, it may negatively affect the application process.

[0093] The two-component epoxy-based intumescent material or the one-component water-based material according to the present invention may further contain a rheology modifier.

[0094] The rheology modifier may be present in the first part of the composition and / or the second part of the composition in a two-part composition and may be the same or different in the first and second parts of the composition.

[0095] The rheology modifier is preferably selected from fumed silica, fused silica, amorphous silica, hydrated silica, mineral nanosilicate clay and mixtures thereof, and more preferably the rheology modifier is fumed silica.

[0096] Fumed silica is a particularly preferred rheology modifier because its presence increases the viscosity of the composition during application (spraying). Examples of such fumed silicas include polydimethylsiloxane-treated silica and hexamethyldisilazane-treated silica.

[0097] Commercially available rheology modifiers suitable for use in the present invention include, but are not limited to, CAB-O-SIL ND-TS, TS610, TS710, and TS720 from Cabot Corporation and AEROSIL R805, R8200, 300, and 200 from Degussa Corporation.

[0098] The two-component, room temperature curable, heat resistant and flame retardant composition according to the present invention may have the rheology modifier present in the first part of the composition in an amount of 0.1 to 5 wt %, preferably 0.2 to 3 wt %, more preferably 0.3 to 1.5 wt %, based on the total weight of the first part, and / or the rheology modifier present in the second part of the composition in an amount of 0.1 to 5 wt %, preferably 0.2 to 3 wt %, more preferably 0.3 to 1.5 wt %, based on the total weight of the second part.

[0099] The one-component water-based material according to the present invention may have 0.1 to 5 wt%, preferably 0.2 to 5 wt%, more preferably 0.2 to 3 wt% of rheology modifier based on the total weight of the first part of the composition.

[0100] The above ranges have been found to be desirable to provide good viscosity characteristics for the first and second parts without increasing the viscosity.

[0101] The two-component epoxy-based intumescent material or the one-component water-based material according to the present invention may further contain a pigment.

[0102] The pigment may be present in the first part of the composition and / or the second part of the composition in a two-component composition and may be the same or different in the first and second parts of the composition.

[0103] The pigment is preferably selected from titanium dioxide, carbon black, graphite, iron oxides and mixtures thereof, preferably the pigment is selected from titanium dioxide, carbon black, iron oxides and mixtures thereof.

[0104] The two-component epoxy-based intumescent material according to the present invention may have the pigment present in the first part of the composition in an amount of 0.1 to 5 wt %, more preferably 0.2 to 3 wt %, even more preferably 0.3 to 1.5 wt %, based on the total weight of the first part, and / or the pigment may be present in the second part of the composition in an amount of 0.1 to 5 wt %, preferably 0.2 to 3 wt %, even more preferably 0.3 to 1.5 wt %, based on the total weight of the second part.

[0105] The one-component water-based material according to the present invention may have 0.1 to 5 wt %, more preferably 0.2 to 3 wt % and even more preferably 0.3 to 1.5 wt % of pigment, based on the total weight of the composition.

[0106] The two-component epoxy-based intumescent material of the present invention is prepared by first combining all the components of the first part in one container and mixing them, then combining all the components of the second part in another container and mixing them, and then combining and mixing the first and second parts before use.

[0107] According to the two-component epoxy-based expansion material of the present invention, the first part and the second part are mixed in a ratio of 1.9:1.1 to 2.1:0.9, preferably in a ratio of 2:1.

[0108] The above range is based on the amount of epoxy resin in the first part and the total amount of amine in the second part, and is preferred because it can result in complete reaction without the presence of unreacted epoxy resin in the final composition.

[0109] The one-component water-based material of the present invention is prepared by combining all ingredients and mixing them.

[0110] Pad or felt

[0111] The term "mat or felt" as used herein refers to any thermally stable mat or felt known in the art. In the present invention, the mat or felt may have different types of surfaces composed of glass fibers.

[0112] Preferably, the mat or felt is a glass fiber mat or felt. When a glass fiber mat or felt is used as the mat or felt in the present invention, the heat resistance, non-conductivity and cost-effectiveness of the fireproof composite material of the present invention are further improved.

[0113] Preferably, the thickness of the mat or felt is 0.2 to 1 mm, preferably 0.2 to 0.7 mm. When the thickness of the mat or felt is within the above range, an optimal balance is achieved between the thickness required to provide sufficient protection and the minimum possible thickness to save installation space in the battery system.

[0114] In a preferred embodiment, the fiber diameter of the mat or felt is 5 μm to 20 μm, preferably 8 μm, 10 μm and / or 13 μm. When the fiber diameter of the mat or felt is within the above range, the production of the mat or felt has sufficient stability.

[0115] In another preferred embodiment of the present invention, the fiber length of the mat or felt is 5 mm to 30 mm. When the fiber length of the mat or felt is within the above range, the production of the mat or felt has sufficient stability.

[0116] Suitable commercially available pads or felts suitable for use in the present invention include, but are not limited to, Johns Manville.

[0117] In another preferred embodiment of the present invention, the mat or felt comprises a binder and / or a coating. The binder can be any conventional binder in the art, preferably a urea-formaldehyde resin and a polymer dispersion. The coating can be any conventional coating in the art, preferably aluminum hydroxide and / or a carbonate sulfate. When urea-formaldehyde resin and a polymer dispersion, and / or aluminum hydroxide and / or a carbonate sulfate are used in the present invention, the heat resistance, electrical non-conductivity, cost-effectiveness, and / or compatibility between the components of the fire-resistant composite material of the present invention are further improved.

[0118] In a preferred embodiment of the invention, a mat or felt is embedded in the coating and / or placed on the surface of the coating.

[0119] The present invention also provides a method for preparing the fire-resistant composite material of the present invention, comprising: applying a liquid-applied coating of the present invention to a substrate; subsequently placing a mat or felt of the present invention on the coating; if necessary, applying another liquid-applied coating of the present invention to the mat or felt; and drying the coating at room temperature or at an elevated temperature (preferably 25 to 90° C.). Preferably, the substrate used in the present invention may be an electroplated coated steel or aluminum substrate, more preferably an electroplated coated steel substrate.

[0120] In a preferred embodiment of the present invention, when the present invention uses a two-component epoxy-based intumescent material as a liquid coating, the two components are mixed, preferably in a ratio of 2:1, to obtain the coating before application.

[0121] The application of the liquid-applied coating and the mixing of the two components (if any) can be carried out using any conventional method and any conventional equipment in the art. Preferably, the liquid-applied coating is applied by a doctor blade method, a spray method, or an advection method. In a preferred embodiment of the present invention, when a two-component epoxy-based intumescent material is used as the liquid-applied coating of the present invention, a stirrer for mixing the two components can be integrated into the equipment used to apply the liquid-applied coating, depending on the degree of automation.

[0122] The present invention also relates to the use of the flame-resistant composite material according to the invention for batteries of electric vehicles, and preferably for battery housings in electric vehicles.

[0123] Furthermore, the present invention relates to an electric vehicle battery comprising the fire-resistant composite material according to the invention.

[0124] In addition, the present invention relates to a method for preparing the electric vehicle battery of the present invention, comprising: preparing the fireproof composite material on the cover and / or shell of the electric vehicle battery according to the preparation method of the fireproof composite material of the present invention. Example

[0125] 1. Preparation of fireproof composite materials

[0126] The fireproof composite material according to Example 1 of the present invention was prepared as follows:

[0127] All the ingredients of the first part in Table 1 below were combined in one container (Flacktec plastic container) and mixed with a Flacktec high-speed mixer to obtain the first part, while all the ingredients of the second part in Table 1 below were combined in another container (Flacktec plastic container) and mixed with a Flacktec high-speed mixer to obtain the second part.

[0128] Table 1

[0129] Part 1

[0130] name Compound wt% DER331, obtained from Olin Epoxy resins based on bisphenol A and epichlorohydrin 42.9 Exolit AP 422, available from Clariant Ammonium polyphosphate 20.3 Apyral 16 Aluminum trihydroxide 27.8 Disflamoll DPK, available from Lanxess Cresyl diphenyl phosphate 7.5 Cab O Sil M 720, available from Cabot Fumed silica 0.5 TiO2 (Rutil) from Kronos Titanium dioxide 1

[0131] Part 2

[0132] name Compound wt% Ancamine 2432, available from Evonik Modified aliphatic amines 27.5 Ancamine 2914UF, available from Evonik Modified aliphatic amines 16.5 Exolit AP 422, available from Clariant Ammonium polyphosphate 27.9 Omya BLH, obtained from Omya calcium carbonate 26.1 Cab O Sil M 5, available from Cabot Fumed silica 1 Bayferrox 306 from Lanxess Iron oxides 1

[0133] Parts 1 and 2 were combined and mixed in a 2:1 ratio to produce a liquid coating. 40 ml of the coating was then applied to a 250 mm x 190 mm electro-coated steel panel using a spatula. A glass fiber mat (610 μm thick, 10 μm fiber diameter, 8 mm fiber length, available from Johns Manville) was then placed over the coating to the dimensions of the area to be protected (150 mm x 105 mm). The resulting composite was cured overnight at room temperature.

[0134] The fireproof composite material according to Example 2 of the present invention was prepared as follows:

[0135] All ingredients in Table 2 below were combined in one container (Flacktec plastic container) and mixed using a Flacktec high speed mixer to obtain a liquid application coating.

[0136] Table 2

[0137] name Compound wt% Tap water Water 27.59 triethanolamine Triethanolamine 85% 0.33 Foamaster MO NXZ from BASF Nonionic surfactant 0.06 Tetrapotassium pyrophosphate Tetrapotassium pyrophosphate 0.30 Kelzan Xanthan gum 0.08 CMC 75a Pulver Carboxymethyl cellulose 0.30 JMAC LP 10% Silver chloride 0.01 FASER, GLAS-, 4.5mm Glass fiber 0.50 Arbocel ZZ 8-1R Glass oxide, non-fibrous 0.50 Omyacarb 4HD Calcium carbonate 6.67 Portaflame SG 100LV Aluminum hydroxide 19.99 KALIUM-ALUMINIUM-SILIKAT Potassium aluminum silicate 5.00 Isopropyl alcohol 2-Propanol, 99.9% 1.00 Muskovit Mica 8.50 Acronal DS 3502, available from BASF Acrylic polymer 15.00 Mica MU 247 Mica 14.17

[0138] The liquid coating was applied to a 250 mm x 190 mm electro-coated steel panel in an amount of 50 ml using a rod coating method. A glass fiber mat (610 μm thick, 10 μm fiber diameter, 8 mm fiber length, available from Johns Manville) cut to the dimensions of the area to be protected (150 mm x 105 mm) was then placed on the coating. The resulting composite was then dried overnight at room temperature.

[0139] The methods for preparing the fire-resistant composite materials of Examples 3 and 4 of the present invention are the same as those of Examples 1 and 2, respectively, except that, before the composite materials are cured, a further liquid coating is applied to the composite materials in the same manner as before the mat is placed. Specifically, the methods for preparing the fire-resistant composite materials of Examples 3 and 4 are as follows: the liquid coating is applied to the electroplated coated steel plate, the glass fiber mat is placed on the coating, the same liquid coating is applied in the same manner as before, and then cured to produce the composite materials.

[0140] 2. Fireproof composite material performance test

[0141] 2.1 Adhesion between test pad and coating

[0142] The fire-resistant composite materials of Example 1 and Example 2 were subjected to three-point bending tests according to ISO 178 (for plastic substrates) and ISO 7438 (for metal substrates). The results showed that both composite materials passed these tests. Figure 1 As shown, the fireproof composite material pad of Example 2 has good adhesion to the coating.

[0143] 2.2 Test whether the pad can be coated with paint

[0144] In order to test whether the coating can be applied to the mat (i.e. whether the liquid fire retardant coating is sufficiently wetted on the mat), visual observations were conducted on both the fire retardant composite materials of Example 3 and Example 4. Figure 2aAs shown in 2a (photograph of the fireproof composite material of Example 4) and 2b (photograph of the fireproof composite material of Example 3), the photos show that both fireproof composite materials have good wettability of the liquid applied fireproof coating on the mat.

[0145] 2.3 Testing heat resistance and adhesion when in contact with flame (flame test)

[0146] The heat spread prevention performance of the fireproof composites of Examples 3 and 4 was tested by comparing them with a control electroplated coated steel plate without any coating or mat. The goal of the fireproof test was to keep the temperature (T2) below 300°C after the composite was exposed to a temperature of 1000°C for 10 minutes.

[0147] Heat propagation test method - basic principles such as Figure 3 As shown in Figure 5 . T2 is the measured temperature, and its change over time is shown in a graph. For example, the graph shows the temperature change over time for the fire-resistant composite material of Example 4 and a control electroplated coated steel plate without any coating or mat. The test results are shown in Figure 5 . The fire-resistant composite material of the present invention performed best in this test, and was able to maintain the temperature (T2) well below 300°C for at least 10 minutes.

[0148] 2.4 Testing the mechanical stability of composite materials during explosion (thermal testing)

[0149] Thermal diffusion testing was conducted using 50Ah prismatic cells on the fire-retardant composite materials of Examples 1 and 2, as well as a control electroplated steel substrate without any coating or mat. The results demonstrated that the fire-retardant composite materials of the present invention were able to protect the electroplated steel substrate; specifically, compared to the control electroplated steel substrate, the electroplated coating of the fire-retardant composite materials of the present invention remained intact on the cold side, thus continuing to provide corrosion protection, as shown in Figure 5. Figure 5a is a photograph of a control electroplated coated steel substrate without any paint or mat, and Figure 5b This is a photo of the fireproof composite material of Example 2 after the thermal runaway test of a 50Ah square battery.

[0150] From the above results it can be seen that the fire-proof composite material according to the present invention shows improvements in fire protection, thermal insulation behavior and mechanical stability.

Claims

1. A fire-resistant composite material made of a liquid-applied coating and a mat or felt.

2. The fire-resistant composite material according to claim 1, wherein the liquid-applied coating is a two-component epoxy-based intumescent material and / or a one-component water-based material with inorganic fillers and / or fibers.

3. The fireproof composite material according to claim 2, wherein the two-component epoxy-based intumescent material comprises: The first part contains 1) Epoxy resin; and 2) flame retardant compounds; as well as The second part contains 1) a first amine comprising N,N'-bis(3-aminopropyl)ethylenediamine and 3,3'-oxybis(ethyleneoxy)bis(propylamine); 2) a second amine comprising meta-xylylenediamine and a polymer of formaldehyde with 1,3-xylylenediamine and phenol; and 3) Flame retardant compounds.

4. The fireproof composite material according to claim 2, wherein the one-component water-based material containing inorganic fillers and / or fibers is a non-reactive water-based dispersion containing an acrylic binder, glass fibers and a flame retardant component.

5. The fire-resistant composite material according to any one of claims 1 to 4, wherein the mat or felt is a glass fiber mat or felt, and / or the mat or felt has a thickness of 0.2 mm to 1 mm, preferably 0.2 mm to 0.7 mm.

6. The fire-resistant composite material according to any one of claims 1 to 5, wherein the fiber diameter of the mat or felt is 5 to 20 μm, preferably 8 μm, 10 μm and / or 13 μm; and / or the fiber length of the mat or felt is 5 to 30 mm.

7. The fire-resistant composite material according to any one of claims 1 to 6, wherein the mat or felt contains a binder and / or a coating; the binder is preferably a urea-formaldehyde resin and a polymer dispersion; the coating is preferably aluminum hydroxide and / or carbonate sulfate.

8. The fireproof composite material according to any one of claims 1 to 7, wherein the thickness of the composite material is 0.2 mm to 4 mm, preferably 0.5 mm to 2 mm.

9. The fire resistant composite material according to any one of claims 1 to 8, wherein the mat or felt is embedded in the coating and / or placed on the surface of the coating.

10. A method for preparing the fireproof composite material according to any one of claims 1 to 9, comprising: applying the liquid coating as defined in any one of claims 1 to 9 to the substrate, preferably by a doctor blade method, a spray method or a flat flow method; Subsequently placing a pad or felt as defined in any one of claims 1 to 9 on the coating; if necessary, applying a further liquid application coating as defined in any one of claims 1 to 9 to the pad or felt; and drying the coating at room temperature or elevated temperature, preferably at 25 to 90°C.

11. Use of the fireproof composite material according to any one of claims 1 to 9 for an electric vehicle battery, and preferably for a battery housing in an electric vehicle.

12. An electric vehicle battery comprising the fireproof composite material according to any one of claims 1 to 9.

13. A method for preparing the electric vehicle battery according to claim 12, comprising: The method according to claim 10 is used to prepare a fireproof composite material on the cover and / or shell of an electric vehicle battery.

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