Flame retardant coating

Abstract

Disclosed herein are coating compositions having flame retardancy and controlled expansion, as well as methods of using such compositions and substrates coated with such compositions.

Description

Technical Field

[0001] The present disclosure relates to flame retardant coating compositions, methods of coating substrates with the compositions, substrates coated with the compositions, and articles comprising the substrates, including energy storage devices. Background Art

[0002] Flame retardant coatings have been used in various structural applications to prevent both cellulose fires and hydrocarbon fires. Such coatings provide protection by providing fire resistance to the coated substrate. Many substrates may benefit from being coated with such coatings, including structural building components used for commercial and transportation infrastructure, such as hotels, airports, concert halls or offshore sites, chemical plants, oil drilling platforms, etc., which are exposed to extreme high temperatures in the event of a fire. Energy storage devices, such as batteries, including lithium-ion batteries, may also be exposed to such high temperatures; many such devices are susceptible to thermal runaway, during which heat and gases are rapidly released and create a fire hazard. Conventional single-component fire protection coatings are not resistant to weathering, and two-component fire protection coatings are too viscous to be applied at low thicknesses; therefore, improved flame retardant coatings are needed, including those used for energy storage devices. Summary of the invention

[0003] The present disclosure relates to a coating composition comprising: a) a film-forming component; b) a phosphoric acid source; c) a TiO 2 ; d) a flame retardant; and e) a gas source; wherein the film-forming component can be present in an amount of 10 wt % to 50 wt %, such as 15 wt % to 40 wt %; the phosphoric acid source can be present in an amount of 15 wt % to 50 wt %, such as 20 wt % to 40 wt %; TiO 2 can be present in an amount of 3 wt % to 15 wt %, such as 3 wt % to 8 wt %; the flame retardant can be present in an amount of 10 wt % to 40 wt %, such as 15 wt % to 30 wt %; and the gas source can be present in an amount of 2 wt % to 20 wt %, such as 2 wt % to 5 wt %, wherein the wt % are based on the total solid weight of the composition.

[0004] The composition can be formed into a self-supporting film or sheet. Methods of coating substrates with a coating composition according to the present disclosure or a film or sheet formed therefrom as described herein and thus coated substrates and articles comprising such coated substrates are also within the scope of the present disclosure, including battery components, batteries and other energy storage devices coated at least in part with the composition of the present invention and / or the self-supporting film or sheet of the present disclosure. DETAILED DESCRIPTION

[0005] The present disclosure relates to a coating composition comprising: a) a film-forming component; b) a phosphoric acid source; c) a TiO 2 ; d) a flame retardant; and e) a gas source. The film-forming component can be present in an amount of 10 wt % to 50 wt %, such as 15 wt % to 40 wt %; the phosphoric acid source can be present in an amount of 15 wt % to 50 wt %, such as 20 wt % to 40 wt %, TiO 2 The flame retardant can be present in an amount of 10 wt % to 40 wt %, such as 15 wt % to 30 wt %, and the gas source can be present in an amount of 2 wt % to 20 wt %, such as 2 wt % to 5 wt %, wherein all wt % are based on the total solid weight of the composition. It should be understood that when the composition is 100% solid, the total solid weight of the composition when uncured will be the same as the total solid weight when cured, which is typical.

[0006] The coating composition of the present invention can be used to form a flame retardant coating. A "flame retardant" coating is a coating that is not easily ignited. A "flame retardant" (and similar terms) coating according to the present disclosure is a substance that, when applied to one side of a 0.8 mm to 1.2 mm thick steel sheet and cured to a dry film thickness of 600 microns + / - 100 microns, and the uncoated side of the steel is exposed to 1450 ± 50 ° C at a heat output of > 5 kW, will not catch fire after being exposed to the flame for five minutes, and when the coke directly above the flame impact area is cut to expose the substrate (and still subject to the flame), it will not catch fire after being exposed to such heat output for five minutes. This test is intended to simulate a thermal runaway event in a battery and is sometimes referred to herein as a "thermal runaway test".

[0007] The coating deposited from the coating composition of the present invention may also provide thermal insulation to the coated substrate. For example, upon exposure to the above-mentioned heat output, the coating of the present invention may undergo an expansion of 4 to less than 20 times its dry film thickness, such as less than 15 or less than 10, such as 5 to 8 times expansion. This expansion is significantly less than the typical expansion of other intumescent coatings under thermal conditions, which typically expand 20 to 50 times. Therefore, it is a feature of the present disclosure to provide a composition having both controlled expansion and flame retardancy as defined above.

[0008] The coating composition according to the present disclosure is particularly suitable for the surface of the energy storage device, especially the outer surface. For example, if applied to the battery used in the electric vehicle, the coating of the present invention (or the sheet / film made thereof) can limit the fire to the battery and prevent the fire from spreading to other parts of the vehicle. For example, if an organic coating such as an electrophoretic coating, a primer or other coating is deposited on the battery box, the coating of the present invention can delay the coating from catching fire even if it cannot prevent the coating from catching fire. The coating of the present invention can also be used on a substrate treated with an inorganic treatment method. The heat insulation of the coating of the present invention can also reduce the heat damage of the outside of the energy storage device (such as other parts of the vehicle or structure).

[0009] The coating composition includes a film-forming component. "Film-forming" means that the composition can form a continuous film on the surface after drying and / or curing. The film-forming component can include, for example, a film-forming resin and a crosslinking agent thereof. Any film-forming resin can be used according to the present disclosure. Such resins can react with themselves, i.e., undergo a self-crosslinking reaction, or can react with a crosslinking agent to form a film. Such reactions can occur at ambient temperature or at an elevated temperature. "Crosslinking agent", curing agent, hardener and similar terms can be used interchangeably herein.

[0010] Any suitable resin or combination of resins can be used in the film-forming component, including but not limited to epoxy resins, acrylic resins, polysiloxane resins, polyurethane resins, polyurea resins, polyethylene resins, phenolic resins, urea-formaldehyde resins, polyimide resins, melamine resins, polyester resins and cyanate resins. Among these resins, epoxy resins, acrylic resins and / or polyurethane resins are particularly suitable.

[0011] The film-forming resins used in accordance with the present disclosure contain one or more functional groups that react with each other or with functional groups on a crosslinking agent. Examples of suitable functional groups include, for example, ketones, hydrazines, carbodiimides, oxazolines, epoxies, amines, vinyls, amides, carbamates, ureas, thiols, carboxylic acids, (meth)acryloyls, isocyanates, alkoxysilyls, anhydrides, hydroxyl and alkoxy groups, functional groups and combinations thereof.

[0012] Suitable functional groups capable of reacting with each other include, for example, N-methylolamide groups; silane groups with silicon-bonded hydrolyzable or condensable groups, such as chloro, hydroxyl, alkoxy, acetoxy and / or ketoximo groups; ethylenically unsaturated fatty acid groups, such as capable of oxidative drying; azomethine groups; azetidine groups; and groups capable of thermally reversible Diels-Alder reactions, such as furan / maleimide. If the resin contains functional groups capable of reacting with each other, it is considered to be self-crosslinking and does not require the presence of a curing agent in the composition of the present invention.

[0013] The resin may also contain a combination of functional groups that can react with each other (self-crosslinking) and functional groups that can react with functional groups of a curing agent. In such cases, a curing agent may be present; after curing, two crosslinking mechanisms occur: a reaction between the functional groups on the crosslinking agent and the resin and a self-crosslinking reaction of the resin itself.

[0014] Suitable epoxy resins for use in the present disclosure include at least one polyepoxide. Polyepoxides typically have at least two 1,2-epoxy groups. The epoxide equivalent weight of the polyepoxide can be in the range of 80 to 6000, such as 100 to 700. Epoxides can be saturated or unsaturated, cyclic, aliphatic, alicyclic, aromatic or heterocyclic. They can include substituents, such as halogen, hydroxyl and ether groups.

[0015] Examples of suitable polyepoxides are those having more than one or usually two 1,2-epoxy equivalents; that is, polyepoxides having an average of two epoxy groups per molecule. The most commonly used polyepoxides are, for example, polyglycidyl ethers of polyphenols, such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), resorcinol, hydroquinone, benzyl alcohol, phloroglucinol, bisphenol F and catechol; or polyglycidyl ethers of polyols, such as cycloaliphatic polyols, such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,1-bis(4-hydroxycyclohexyl)ethane, 2-methyl-1,1-bis(4-hydroxycyclohexyl)propane, 2,2-bis(4-hydroxy-3-tert-butylcyclohexyl)propane, 1,3-bis(hydroxymethyl)cyclohexane and 1,2-bis(hydroxymethyl)cyclohexane. Specifically, examples of the aliphatic polyol include trimethylolpentanediol, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,2,6-hexanetriol, cyclohexanedimethanol, glycerol, trimethylolpropane, hydrogenated bisphenol A, hydrogenated bisphenol F or polyether diols such as poly(oxytetramethylene) glycol, poly(oxyethylene) glycol, poly(oxypropylene) glycol and neopentyl glycol.

[0016] Another group of suitable epoxy resins include polyglycidyl ethers of polycarboxylic acids, formed by reacting an epoxy compound (such as epichlorohydrin) with an aliphatic or aromatic polycarboxylic acid (such as oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid or dimerized linoleic acid). Such resins are commercially available from Hexion Inc. in its EPIKOTE and EPON series.

[0017] Other suitable epoxy resins that can be used in accordance with the present disclosure include epoxidized ethylenically unsaturated alicyclic materials, such as epoxy alicyclic ethers and esters, epoxy resins containing oxyalkylene groups, epoxy novolac resins (which are prepared by reacting an epihalohydrin with a condensation product of an aldehyde and a monohydric or polyhydric phenol), such as epoxy novolac resins or epoxy cresol novolac resins.

[0018] In addition, according to the present disclosure, it may be advantageous to employ flexible polyepoxide resins as the polyepoxide functional compound of the compositions of the present disclosure. These resins are generally substantially linear materials, although a small amount of branching is tolerated. Examples of suitable materials are epoxidized soybean oil, dimer acid-based materials (such as EMPOL 1010 resin commercially available from BASF SE of Ludwigshafen, Germany), and rubber-modified polyepoxide resins (such as products prepared from polyglycidyl ethers of bisphenol A and acid-functional polybutadiene).

[0019] Other suitable examples of flexible polyepoxides used according to the present disclosure include epoxy functional adducts prepared from flexible acid functional polyesters and polyepoxides. The acid functional polyesters may have an acid value of at least 10 mg KOH / g, such as 140 mg to 350 mg KOH / g or 180 mg to 260 mg KOH / g as determined by ASTM 974-87.

[0020] Linear polyesters may be more suitable for use herein than branched polyesters. Acid functional polyesters can be prepared by polyesterification of organic polycarboxylic acids or their anhydrides with organic polyols. The polycarboxylic acids and polyols can be aliphatic or aromatic dibasic acids and diols.

[0021] The diols that can be used to make the polyesters include alkylene glycols such as ethylene glycol, diethylene glycol, neopentyl glycol, and other diols such as hydrogenated bisphenol A, cyclohexanediol, cyclohexanedimethanol, caprolactone diols, for example, the reaction products of ε-caprolactone with ethylene glycol, hydroxyalkylated bisphenols, polyether diols (e.g., poly(oxytetramethylene) glycol, poly(oxyethylene) glycol, poly(oxypropylene) glycol, etc.). Higher functionality polyols can also be used, although diols may be more suitable. Examples include trimethylolpropane, trimethylolethane, pentaerythritol, glycerol, isosorbide, tetramethylcyclobutane diol, etc., as well as higher molecular weight polyols such as those prepared by alkoxylating lower molecular weight polyols.

[0022] The acid component of the polyester may include monomeric dicarboxylic acids or anhydrides having from 2 to 36 carbon atoms per molecule. Suitable acids include, for example, phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, glutaric acid, chlorendic acid, tetrachlorophthalic acid, tetrabromophthalic acid, sebacic acid, dodecanedioic acid, abietic acid, diphenolic acid, gallic acid and various types of other dicarboxylic acids, such as unsaturated C 18 Diels-Alder adducts of fatty acids.

[0023] Polyester can contain trace monoacids, such as benzoic acid, stearic acid, acetic acid, hydroxystearic acid and oleic acid. Similarly, higher polycarboxylic acids, such as trimellitic acid, can be adopted. In the case of the acid mentioned above, it is understood that the anhydrides of those acids that form anhydrides can be used to replace the acid. In addition, the lower alkyl esters of the acid can be used, such as dimethyl glutarate and dimethyl terephthalate.

[0024] According to the present disclosure, the polyester used to prepare the epoxy functional adduct can be prepared from a polycarboxylic acid component comprising a polycarboxylic acid or mixture of acids having 7 to 16 carbon atoms and a polyol component comprising a portion of diethylene glycol.

[0025] The polyepoxides that can be used to prepare the epoxy-functional adduct of the flexible acid-functional polyester and the polyepoxide can be selected from those as defined above for the polyepoxide-functional component according to the present disclosure.

[0026] Other suitable polyepoxide functional compounds are epoxy functional acrylic resins. Such resins can be prepared by free radical addition polymerization of (meth)acrylic monomers, optionally in combination with vinyl monomers or other monomers comprising at least one carbon-carbon double bond, wherein the monomer composition comprises at least one epoxy functional compound having at least one carbon-carbon double bond.

[0027] Suitable epoxy-functional ethylenically unsaturated monomers include, for example, glycidyl (meth)acrylate, allyl glycidyl ether, vinyl glycidyl ether, vinyl cyclohexene oxide, limonene oxide, 2-ethyl glycidyl acrylate, 2-ethyl glycidyl methacrylate, 2-(n-propyl) glycidyl acrylate, 2-(n-propyl) glycidyl methacrylate, 2-(n-butyl) glycidyl acrylate, 2-(n-butyl) glycidyl methacrylate, glycidyl methyl methacrylate, glycidyl acrylate, (3',4'-epoxyheptyl)-2-ethyl acrylate, (3',4'-epoxyheptyl)-2-ethyl methacrylate, (6',7'-epoxyheptyl) acrylate, (6',7'-epoxyheptyl) methacrylate, allyl-3,4-epoxyheptyl ether, 6,7-epoxyheptyl allyl ether, vinyl-3,4-epoxyheptyl ether, 3,4-epoxyheptyl vinyl ether, 6,7-epoxyheptyl vinyl ether, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, p-vinylbenzyl glycidyl ether, 3-vinylcyclohexene oxide, α-methyl glycidyl methacrylate, 3,4-epoxycyclohexyl methyl (meth)acrylate, and combinations thereof.

[0028] Suitable additional monomers for preparing epoxy-functional acrylic resins include, for example, ethylenically unsaturated nitrile compounds; vinyl aromatic monomers; alkyl esters of ethylenically unsaturated acids; hydroxyalkyl esters of ethylenically unsaturated acids; amides of ethylenically unsaturated acids; ethylenically unsaturated acids; ethylenically unsaturated sulfonic acid monomers and / or ethylenically unsaturated phosphorus acid monomers; vinyl carboxylates; conjugated dienes; monomers having at least two ethylenically unsaturated groups; and combinations thereof.

[0029] Examples of ethylenically unsaturated nitrile monomers that can be used to prepare epoxy-functional acrylic resins include polymerizable unsaturated aliphatic nitrile monomers containing 2 to 4 carbon atoms in a linear or branched arrangement, which may be substituted with acetyl or other nitrile groups. Such nitrile monomers include acrylonitrile, methacrylonitrile, α-cyanoethylacrylonitrile, fumaronitrile, and combinations thereof, with acrylonitrile being particularly suitable.

[0030] Representative suitable vinyl aromatic monomers include, for example, styrene, alpha-methylstyrene, para-methylstyrene, tert-butylstyrene, and vinyltoluene.

[0031] Esters of (meth)acrylic acid that can be used to prepare epoxy-functional acrylic resins include n-alkyl, isoalkyl or tert-alkyl esters of acrylic acid or (meth)acrylic acid, wherein the alkyl group has 1 to 20 carbon atoms, the reaction products of methacrylic acid with the glycidyl ester of neo acids (such as versatic acid, neodecanoic acid or neopentanoic acid) and hydroxyalkyl (meth)acrylate and alkoxyalkyl (meth)acrylate monomers.

[0032] Suitable alkyl (meth)acrylates may include, for example, C 1 -C 20 Alkyl (meth) acrylates, such as C 1 -C 10 -alkyl (meth)acrylates. Examples of such acrylate monomers include n-butyl acrylate, sec-butyl acrylate, methyl acrylate, ethyl acrylate, hexyl acrylate, tert-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, 4-methyl-2-pentyl acrylate, 2-methylbutyl acrylate, methyl methacrylate, butyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, ethyl methacrylate, isopropyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, and cetyl methacrylate. Esters of (meth)acrylic acid, such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and combinations thereof, are particularly suitable.

[0033] Hydroxyalkyl (meth) acrylate monomers that can be used to prepare epoxy functional acrylic resins include, for example, hydroxyalkyl acrylate and methacrylate monomers based on ethylene oxide, propylene oxide and higher alkylene oxides or mixtures thereof. Examples are hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate and hydroxybutyl acrylate. Particularly suitable is 2-hydroxyethyl (meth) acrylate.

[0034] Amides of ethylenically unsaturated acids that can be used to prepare epoxy-functional acrylic resins include, for example, acrylamide, methacrylamide, and diacetone acrylamide.

[0035] Vinyl ester monomers useful in preparing epoxy functional acrylic resins include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, ethyl vinyl-2-hexanoate, vinyl stearate, and vinyl esters of trans acids.

[0036] Ethylenically unsaturated carboxylic acid monomers suitable for preparing epoxy functional acrylic resins include, for example, monocarboxylic acids and dicarboxylic acid monomers and monoesters of dicarboxylic acids. Particularly suitable are ethylenically unsaturated aliphatic monocarboxylic acids or dicarboxylic acids or anhydrides containing 3 to 5 carbon atoms. Examples of monocarboxylic acid monomers include acrylic acid, methacrylic acid, crotonic acid, and examples of dicarboxylic acid monomers include fumaric acid, itaconic acid, maleic acid and maleic anhydride. Examples of other suitable ethylenically unsaturated acids include vinylacetic acid, vinyl lactic acid, vinyl sulfonic acid, 2-methyl-2-propylene-1-sulfonic acid, styrene sulfonic acid, acrylamidomethylpropanesulfonic acid and salts thereof. Suitable ethylenically unsaturated carboxylic acid monomers include (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid and combinations thereof.

[0037] Conjugated diene monomers suitable for preparing epoxy functional acrylic resins include conjugated diene monomers such as 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2,4-hexadiene, 1,3-octadiene, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 3,4-dimethyl-1,3-hexadiene, 2,3-diethyl-1,3-butadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, 3,7-dimethyl-1,3,6-octatriene , 2-methyl-6-methylene-1,7-octadiene, 7-methyl-3-methylene-1,6-octadiene, 1,3,7-octatriene, 2-ethyl-1,3-butadiene, 2-pentyl-1,3-butadiene, 3,7-dimethyl-1,3,7-octatriene, 3,7-dimethyl-1,3,6-octatriene, 3,7,11-trimethyl-1,3,6,10-dodecatetraene, 7,11-dimethyl-3-methylene-1,6,10-dodecatriene, 2,6-dimethyl-2,4,6-octatriene, 2-phenyl-1,3-butadiene and 2-methyl-3-isopropyl-1,3-butadiene and 1,3-cyclohexadiene and combinations thereof.

[0038] It is also possible to use a combination of two or more (such as three or more or four or more) different polyepoxy-functional compounds, such as any disclosed above, in the film-forming component.

[0039] Suitable polyepoxy functional compounds used according to the present disclosure can include, for example, the diglycidyl ether of bisphenol A, the diglycidyl ether of bisphenol F, resorcinol diglycidyl ether, epoxy phenol novolac resin, epoxy cresol novolac resin, epoxy-functional (poly) siloxane, epoxy-functional polysulfide, acid-functional polyester and epoxy-functional adducts of polyepoxide, such as those described above. Acrylic resin used in the present disclosure can include, for example, one or more acrylic acid or methacrylic acid alkyl esters optionally with one or more other polymerizable ethylenically unsaturated monomers together copolymer. Useful alkyl esters of acrylic acid or methacrylic acid include, for example, aliphatic alkyl esters containing 1 to 30 carbon atoms (and such as 4 to 18 carbon atoms) in the alkyl group. Non-limiting examples include, for example, methyl methacrylate, ethyl methacrylate, butyl methacrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate. Suitable other copolymerizable ethylenically unsaturated monomers include, for example, vinyl aromatic compounds such as styrene and vinyl toluene; nitriles such as acrylonitrile and 4-methacrylonitrile; vinyl and vinylidene halides such as vinyl chloride and vinylidene fluoride and vinyl esters such as vinyl acetate.

[0040] Acrylic copolymers may contain hydroxyl functional groups, which are typically incorporated into the polymer by including one or more hydroxyl functional monomers in the reactants used to produce the copolymer. Useful hydroxyl functional monomers include hydroxyalkyl acrylates and hydroxyalkyl methacrylates, which typically have 2 to 4 carbon atoms in the hydroxyalkyl group, such as hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, caprolactone, and hydroxyl functional adducts of hydroxyalkyl acrylates, and the corresponding methacrylates, and the beta-hydroxy ester functional monomers described below. Acrylic polymers can also be prepared using N-(alkoxymethyl)acrylamide and N-(alkoxymethyl)methacrylamide.

[0041] The beta-hydroxy ester functional monomers can be prepared from ethylenically unsaturated epoxy functional monomers and carboxylic acids having from 5 to 20 carbon atoms, or from ethylenically unsaturated acid functional monomers and epoxy compounds containing at least 5 carbon atoms which are not polymerizable with the ethylenically unsaturated acid functional monomers.

[0042] The film-forming resin used in the present disclosure may also include polyurethane. The polyurethane that can be used includes polymeric polyols prepared by reacting polyester polyols or acrylic polyols (such as those mentioned above) with polyisocyanates so that the OH / NCO equivalent ratio is greater than 1:1, thereby free hydroxyl groups are present in the product.

[0043] According to the present disclosure, the film-forming component may include a combination of epoxy resin and acrylic resin or epoxy resin and polyurethane resin, such as disclosed in US 5,108,832 or US 5,070,119.

[0044] If the film-forming component comprises an epoxy resin and a polyamine and / or polythiol functional compound as a curing agent, as will be discussed below, the film-forming component may further comprise (i) a β-hydroxy ester of (meth)acrylic acid; (ii) a (meth)acrylate functional compound different from compound (i); or a combination thereof.

[0045] The β-hydroxy ester of (meth)acrylic acid may comprise a β-hydroxy ester of a plurality of (meth)acrylate groups resulting from the reaction of a polyepoxide with (meth)acrylic acid. The polyepoxide may be reacted with the (meth)acrylic acid in an epoxycarboxylic acid equivalent ratio of 1:0.1 to 1:1.2, suitably 1:0.5 to 1:1.2, more suitably 1:1 to 1:1.05. A particularly suitable β-hydroxy ester of (meth)acrylic acid is the reaction product of EPIKOTE 828 (the reaction product of bisphenol A and epichlorohydrin) and acrylic acid, commercially available from Allnex as EBECRYL 3720.

[0046] The polyepoxides that can be used for the reaction product of the polyepoxide and (meth)acrylic acid may be those disclosed above.

[0047] In addition to or in place of the β-hydroxy ester (i) of (meth) acrylic acid, a (meth) acrylate functional compound (ii) different from compound (i) may be present in the film-forming component. The viscosity of the composition of the present disclosure can be adjusted thereby. Therefore, it is believed that the optional component (ii) plays the role of a reactive diluent. The optional (meth) acrylate functional component (ii) of the composition of the present invention may include, for example, 1,4-butylene glycol, neopentyl glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, p-xylene glycol, 1,4-cyclohexanediol, trimethylolethane, trimethylolpropane, pentaerythritol, polyether glycol, for example, poly (oxytetramethylene) glycol, poly (oxyethylene) glycol, poly (oxypropylene) glycol and poly (meth) acrylates of combinations thereof.

[0048] As mentioned above, the film-forming component may also include a crosslinking agent. Any suitable crosslinking agent may be used according to the present disclosure and will be selected by those skilled in the art to react with the functional groups of the film-forming resin. Suitable crosslinking agents include, for example, polyamines, such as polyetheramines, polyamides, polyepoxides, aminoplast resins, phenolic resins, polyisocyanates, polythiols and polyols, etc.

[0049] The curing agent may also be a latent or blocked curing agent, wherein the actual functional group reactive with the functional group of the film-forming resin is generated or restored in a deblocking reaction under curing conditions such as elevated temperature. Suitable curing agents of the type described are, for example, blocked polyisocyanates. Thus, the term polyisocyanate as used herein encompasses blocked and free polyisocyanates. Latent or blocked curing agents are particularly suitable for providing a one-component composition to ensure adequate storage stability and pot life prior to application and curing.

[0050] The polyamine curing agent may include, for example, aliphatic polyamines, aromatic polyamines, polyamine amides, polyetheramines, such as those commercially available from Huntsman Corporation, The Woodlands, Texas, polysiloxane amines, polysulfide amines, or combinations thereof. Examples include diethylenetriamine, 3,3-amino-bispropylamine, triethylenetetramine, tetraethylenepentamine, meta-xylylenediamine, isophoronediamine, 1,3-bis(aminoethyl)cyclohexane, bis(4-aminocyclohexyl)methane, N-aminoethylpiperazine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, and diaminodiphenyl sulfone, as well as reaction products of polyamines and aliphatic fatty acids, such as the series of materials sold by BASF under the trademark VERSAMID, which are particularly suitable.

[0051] In addition, adducts of any of the above polyamines may also be used. The adducts of polyamines are formed by reacting a polyamine with a suitable reactive compound such as an epoxy resin. This reaction will reduce the free amine content in the curing agent, thereby making the curing agent more useful in low temperature and / or high humidity environments.

[0052] As curing agents, various polyetheramines may also be used, such as the various JEFFAMINEs available from Huntsman Corp., including, but not limited to, JEFFAMINE D-230, JEFFAMINE D-400, JEFFAMINE 600, JEFFAMINE 1000, JEFFAMINE 2005, and JEFFAMINE 2070.

[0053] As a curing agent, various polyamides can also be used. Usually, polyamide contains the reaction product of dimerized fatty acid and polyvinylamine, and a small amount of monomeric fatty acid. Dimerized fatty acid is prepared by oligomerization of monomeric fatty acid. Polyvinylamine can be any higher polyvinylamine, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc., of which diethylenetriamine is the most commonly used. When polyamide is used as a curing agent, it can impart one or more desirable properties to the coating, such as corrosion resistance, water resistance and / or good flexibility.

[0054] Polythiol compounds useful as curing agents may include polysulfide thiols, polyether thiols, polyester thiols, pentaerythritol-based thiols; or combinations thereof. A particularly suitable polythiol compound is THIOPLAST G4, commercially available from AkzoNobel Functional Chemicals GmbH & Co KG, Greiz, Germany.

[0055] As described above, if the film-forming resin includes an epoxy resin polyamine, a polythiol compound, or a combination thereof, it can be used as a crosslinking agent.

[0056] In the coating composition of the present disclosure, the equivalent ratio of combined functional groups in the film-forming resin (such as epoxy groups if an epoxy resin is used) to the functional groups in the curing agent can be 2:1 to 1:2, such as 1.05:1.0 to 1:2, or 1:1.4 to 1:2.

[0057] The coating composition can include any appropriate amount of film-forming component. For example, the coating composition can contain 10 wt % or more of film-forming component, such as 30 wt % or more or 40 wt % or more. The coating composition can, for example, include 50 wt % or less of film-forming component, such as 40 wt % or less or 20 wt % or less. The coating composition can, for example, include a film-forming component of an amount between any of the above values, such as 10 wt % to 50 wt %, 15 wt % to 40 wt % or 20 wt % to 50 wt %. Unless otherwise stated, the wt % reported herein is based on the total solid weight of the composition.

[0058] The coating composition of the present disclosure further comprises a phosphoric acid source. As used herein, "phosphoric acid source" means any phosphorus-containing material comprising phosphoric acid or its condensation or dehydration product (including oxide), or any of the aforementioned salts, esters, amides or other derivatives. The phosphoric acid source can include a variety of materials, such as, for example, phosphoric acid, monoammonium phosphate and diammonium phosphate, triphenyl phosphate, tris-(2-chloroethyl) phosphate, tris(2-chloroisopropyl) phosphate, phosphoric acid amides (such as phosphoramide) and melamine pyrophosphate. Suitably, the phosphorus source is a phosphoric acid source of the formula (NH 4 ) n+2 P n O 3n+1 The polyphosphate of ammonium represented by wherein n is an integer of at least 2, and suitably n is an integer of at least 50. The composition of the present disclosure may include a phosphoric acid source of 15 wt % or more, such as, for example, 20 wt % or more, 25 wt % or more, or 30 wt % or more, 35 wt % or more, or 40 wt % or more. The coating composition may include a phosphoric acid source of 50 wt % or less, such as 45 wt % or less, or 40 wt % or less, or 35 wt % or less. The coating composition may include a phosphoric acid source of the amount in the range between any of the above values, such as 15 wt % to 50 wt %,, for example, 20 wt % to 40 wt % or 15 wt % to 35 wt %. The weight % reported herein is based on the total solid weight of the composition. It is believed that phosphorus plays the role of a coke promoter in the composition of the present invention.

[0059] The composition of the present disclosure further comprises titanium dioxide (TiO 2). The composition according to the present disclosure may include TiO in an amount of 3 wt % or greater, such as 6 wt % or greater, or 7 wt % or greater, or 8 wt % or greater, or 9 wt % or greater, or 10 wt % or greater. 2 The coating composition may include TiO in an amount of 20 wt % or less, such as 15 wt % or less, or 18 wt % or less, or 17 wt % or less, or 15 wt % or less, or 13 wt % or less, or 10 wt % or less. 2 The composition can include TiO in an amount within a range between any of the above values. 2 , such as 3 wt % to 20 wt %, such as 3 wt % to 8 wt %, or 5 wt % to 15 wt %. The wt % reported above are each based on the total solid weight of the composition. It should be understood that due to the TiO 2 (and optionally other pigments as discussed below), the compositions of the present disclosure are opaque. That is, the compositions are not optically clear.

[0060] The compositions of the present disclosure further comprise a flame retardant. Suitable flame retardants include ammonium polyphosphate, tris(1-chloro-2-propyl)phosphate, ammonium pentaborate, metal hydroxides and halogenated resins. Particularly suitable flame retardants are those that release water when heated, such as hydrated metal oxides, including Al(OH) 3 and Mg(OH) 2 The coating composition may include a flame retardant in an amount of 10 wt % or more, such as 15 wt % or more, or 20 wt % or more. The coating composition may include a flame retardant in an amount of 50 wt % or less, such as 35 wt % or less, or 30 wt % or less. The composition may include a flame retardant in an amount within a range between any of the above values, such as 10 wt % to 40 wt %, or 15 wt % to 30 wt %. The wt % reported above is based on the total solid weight of the composition. Using a flame retardant in an amount less than 10 wt % will significantly increase the chance of the coating catching fire.

[0061] The coating composition of the present invention further comprises a gas source. "Gas source" refers to a compound that provides an expansion gas after thermal decomposition. The expansion gas is used to cause the composition of the present invention to foam and swell when exposed to high temperature or flame. Due to this expansion, the coke formed is a thick, porous material that is used to insulate and protect the substrate below. Any suitable expansion gas source can be used in the composition of the present invention, such as a nitrogen-containing material. Examples of suitable nitrogen-containing materials include melamine, phosphates, guanidine salts, hydroxymethylated melamine, hexamethoxymethyl melamine, urea, dimethyl urea, pyrophosphate melamine, dicyandiamide, guanidinourea phosphate and glycine. Other conventional expansion gas sources can also be used, such as those that release carbon dioxide. Examples are alkaline earth metals, such as calcium carbonate or magnesium carbonate. Compounds that release water vapor when decomposed after heating can also be used, such as calcium hydroxide, magnesium hydroxide or aluminum hydroxide, and expandable graphite can also be used. Other examples of such compounds are also boric acid sources, such as boric acid and boric acid derivatives, such as boric acid esters and metal borates. Gas source such as melamine can be used in the composition of the present disclosure with 2 wt % or more, such as 3 wt % or more or 4 wt % or more. According to the composition of the present disclosure, the gas source of the amount of for example 20 wt % or less, 10 wt % or less, or 8 wt % or less, or 7 wt % or less, or 5 wt % or less can be included. The gas source of the amount in the range between any of the above values ​​can be included, such as 2 wt % to 20 wt %, such as 2 wt % to 5 wt %. The weight % reported is based on the total solid weight of the composition respectively.

[0062] The coatings of the present disclosure may include one or more additional additives suitable for use in intumescent coatings. Examples of such additives include boric acid sources, aluminum sources, silica sources, zinc sources, acid sources, metal oxides such as prehydrolyzed tetraethyl orthosilicate, titanium isopropoxide, carbon sources, inorganic fillers, glass fibers and / or mineral fibers such as CHOPVANTAGE from PPG, Coatforce or Roxul fibers from Lapinus, rheological additives, organic solvents, pigments, foam stabilizers, and combinations thereof.

[0063] As used herein, "boric acid source" means any boron-containing material containing boric acid or its condensation or dehydration products (including oxides), or any of the aforementioned salts or esters. Suitable borate sources include, for example, ammonium pentaborate, boric acid, metal borates (such as zinc borate), boron oxide, borates (such as sodium borate, potassium borate and ammonium borate), boric esters (such as butyl borate or phenyl borate) and combinations thereof. Suitable aluminum sources include, for example, aluminum hydroxide, aluminum oxide (aluminum oxide), aluminum chloride, aluminum salts and combinations thereof. For example, the aluminum source may include aluminum hydroxide and / or aluminum oxide. As used herein, "silicon dioxide source" means any silicon-containing material containing polysiloxanes, silanes, silicic acid, their condensation or dehydration products (including oxides), or any of the aforementioned salts or esters. Suitable silicon dioxide sources include, for example, fumed silica or quartz, such as those having a particle size of less than 150 μm, or silicon dioxide-containing substances such as bentonite or kaolin.

[0064] If used, the boric acid source can be used in any suitable amount, with 5 wt % or more, such as 6 wt % or more, such as 7 wt % or more, such as 8 wt % or more, such as 9 wt % or more, such as 10 wt % or more. The coating composition can include 20 wt % or less, such as 19 wt % or less, or 18 wt % or less, or 15 wt % or less of the boric acid source. The coating composition can include the boric acid source of the amount in the range between any of the above values, such as 5 wt % to 20 wt %, or 6 wt % to 15 wt %, or 9 wt % to 15 wt %. The composition of the present disclosure can include any suitable amount of water release source (if used), such as 0.1 wt % or more, such as 0.2 wt % or more, or 0.3 wt % or more, or 0.5 wt % or more, or 1 wt % or more, or 3 wt % or more, or 5 wt % or more. The expansion composition of the present disclosure can include any suitable amount of silicon dioxide source, such as 0.1 wt % or more, for example 0.2 wt % or more, or 0.3 wt % or more, or 0.4 wt % or more, or 0.5 wt % or more. The amount of silicon dioxide source included in the coating composition can be 5 wt % or less, such as 3 wt % or less, or 2 wt % or less, or 1 wt % or less, or 0.8 wt % or less. The composition can include a silicon dioxide source in an amount between any of the above values, for example 0.1 wt % to 5 wt %, for example 0.4 wt % to 1 wt %. The weight % reported above is each based on the total solid weight of the composition.

[0065] The optional zinc source may include a variety of materials. It is believed that zinc materials may help form small cell structures in the coke. The small pores of the coke can provide better substrate insulation and can better maintain the integrity of the coke and adhere to the substrate. Therefore, cracking of the coke and its breakage from the substrate are minimized, and greater protection is provided for the underlying substrate. Examples of suitable materials as zinc sources include zinc oxide, zinc salts such as zinc borate and zinc phosphate, zinc carbonate; zinc metal may also be used.

[0066] The acid source may be selected from ammonium phosphate, ammonium polyphosphate, diammonium diphosphate, diammonium pentaborate, phosphoric acid generating materials, boric acid, metal or organic borates, and combinations thereof.

[0067] It should be understood that many components of the present composition can perform more than one function in the composition. That is, a single material can be the source of more than one of the listed components of the composition. For example, melamine pyrophosphate can provide both a phosphorus source and an expansion gas source, zinc borate can provide a zinc source and a borate source; zinc phosphate can provide a zinc source and a phosphate source, and so on.

[0068] Optional reinforcing filler can be selected from a large number of conventionally used materials, including fiber reinforcement and sheet reinforcement, which may be more suitable than other fillers. The example of fiber reinforcement includes glass fiber, ceramic fiber, such as aluminum oxide / silicon oxide, graphite fiber, mineral fiber and basalt fiber. Thin sheet reinforcement includes hammer mill glass flake, mica and wollastonite. Other suitable fillers include metal oxides, clay, talcum powder, silicon dioxide, diatomaceous earth, LAPINUS fiber and various pigments. Reinforcing filler is considered to help control the expansion of fireproof composition before and during coke formation, so that the coke produced is hard and uniform. Based on the total solid weight of intumescent composition, when present, reinforcing filler, such as glass fiber and / or mineral fiber, is usually present in the composition with 5.0 weight % or less, such as 4 weight % or less, such as 3 weight % or less amount. Composition according to the present disclosure can for example include 0.1 weight % or greater, such as 0.2 weight % or greater, 0.5 weight % or greater or 1 weight % or greater amount of reinforcing filler. The composition can include the reinforcing filler in an amount within a range between any of the above values, such as 0.1 wt % to 5.0 wt % or 1 wt % to 4 wt %. The reported wt % are each based on the total solids weight of the composition.

[0069] The compositions of the present disclosure may also contain various conventional additives, such as rheological additives, organic solvents, foam stabilizers, TiO 2Pigment etc. other than these compositions are optional, and can be added with different amounts.Usually, if additional additives are used, the additional additives are present in a total amount of 1 % by weight or more, such as 2 % by weight or more, or 5 % by weight or more, or 10 % by weight or more. Additional additives (if used) can be present in compositions according to the present disclosure, for example, in an amount of 20 % by weight or less, such as 15 % by weight or less, or 12 % by weight or less. Composition can be included in the optional additional additives of the amount in the range between any of the above values, such as 1 % by weight to 20 % by weight, such as 2 % by weight to 20 % by weight or 5 % by weight to 15 % by weight. The reported % by weight is each based on the total solid weight of composition.

[0070] It may also be desirable for the coating compositions of the present disclosure to specifically exclude certain chemicals or components. For example, the compositions of the present invention may be substantially free, essentially free, or completely free of one or more of the following: a boric acid source; an alkylphosphonic acid; melamine; ethylenically unsaturated monomer residues such as those from (meth)acrylic acid and / or styrene; surfactants, including but not limited to nonionic surfactants; silicates, including but not limited to layered silicates and aluminum silicates; and piperazine salts. "Substantially free" as used in this context means that the composition contains 2% by weight or less of any of these compounds, "essentially free" means 1% by weight or less of any compound, and "completely free" means that the compound is contained, if at all, in only trace amounts, such as being present as an impurity in another compound.

[0071] The composition of the present invention may be one component ("1K"), or a multi-component composition such as a two-component ("2K") or more. A 1K composition will be understood to refer to a composition in which all coating components are maintained in the same container after manufacture, during storage, etc. The 1K composition may be applied to a substrate and cured by any conventional means, such as by heating, forced air, etc. The present composition may also be multi-component, which will be understood to be a composition in which the various components are maintained separately until prior to application. The present composition may be thermoplastic or thermosetting. For example, the present composition may be packaged as a 2K system, wherein the film-forming resin is in a first package (A) and the curing agent is in a second package (B), whereby all other components used in the coating composition are used in package (A) or package (B) or both in any combination, or some or all components may be in one or more additional packages (C). The individual packages are mixed together prior to use of the intumescent composition.

[0072] The coating composition of the present invention may be in the form of a viscous material, such as a mastic. It is particularly suitable that the composition is solvent-free and sprayed. If necessary, various conventional solvents (such as xylene, dichloromethane or 1,1,1-trichloroethane) may be used for dilution.

[0073] The coating composition of the present disclosure can be applied to provide various desired dry film thicknesses. Suitable dry film thickness ranges are 10 to 20,000 microns, such as 50 to 5000 microns, such as 100 to 2000 microns. The desired dry film thickness ("DFT") may vary depending on the application. For use in building structural components, a DFT range of 200 to 20,000 microns (such as 300 to 1000 microns or 3000 to 15000 microns) may be suitable. For use on lithium batteries, a DFT in the range of 200 to 5000 microns (such as 200 to 1000, such as 600+ / -100) may be suitable.

[0074] Alternatively, the composition of the present disclosure can be formed into a self-supporting film or sheet. The self-supporting film or sheet can be subsequently cured to form a crosslinked intumescent self-supporting film or sheet. Generally speaking, the curable composition of the present disclosure can be formed into a film or sheet by any technology well known to those skilled in the art, such as a casting molding process, by impregnating a mesh with a coating, etc. The film or sheet can be cured to form a crosslinked self-supporting film or sheet, which can then be applied to a substrate. Also within the present disclosure is that after the formation step, an uncured film or sheet is applied to a substrate, and then subsequently cured to obtain a crosslinked expansion layer according to the present disclosure. The film or sheet can be applied to a substrate by an adhesive. Therefore, when the substrate or similar term of the composition of the present invention referred to herein is "coated", this includes coating by applying a film and / or sheet formed by the composition.

[0075] The compositions and self-supporting sheets or films of the present invention can be applied to any substrate known in the art, such as automotive substrates, marine substrates, industrial substrates, heavy equipment, packaging substrates, wood, wood floors and furniture, clothing, electronic products, including housings and circuit boards and including consumer electronics, such as housings of computers, notebooks, smart phones, tablet computers, televisions, gaming devices, computer equipment, computer accessories, MP3 players, etc., glass and transparent films, including sports equipment for golf, etc. These substrates can be, for example, metallic or non-metallic. Metallic substrates include tin, steel, tin-plated steel, chrome-passivated steel, galvanized steel, aluminum and aluminum foil. As used herein, metal sheet refers to flat metal sheet and coiled metal sheet, which is coiled, unrolled to be coated and then rewound to be shipped to the manufacturer. Non-metallic substrates include polymers, plastics, polyesters, polyolefins, polyamides, cellulose, polystyrene, polyacrylic acid, poly(ethylene naphthalate), polypropylene, polyethylene, nylon, EVOH, polylactic acid, other "green" polymer substrates, poly(ethylene terephthalate) ("PET"), polycarbonate, polycarbonate propylene butadiene styrene ("PC / ABS"), SMC, carbon fiber, polyamide, wood, sheet, wood composites, particle board, medium density fiberboard, cement, stone, glass, paper, cardboard, textiles, synthetic and natural leather, etc. The substrate can be part of a structure or part of a vehicle. As used herein, "structure" refers to any part of a building, bridge, transportation infrastructure, oil rig, oil platform, water tower, transmission line tower, support structure, wind turbine, wall, pier, pier, levee, dam, shipping container, truck, and any metal structure exposed to a corrosive environment. As used herein, "vehicle" in its broadest sense refers to all types of vehicles, such as, but not limited to, automobiles, trucks, buses, tractors, harvesters, heavy equipment, vans, golf carts, motorcycles, bicycles, rail cars, subway cars, airplanes, helicopters, watercraft of various sizes, and the like.

[0076] The substrate can be a substrate that has been treated in some way, such as imparting visual and / or color effects. For example, before applying the coating composition, the substrate can be alkaline cleaned, deoxidized, mechanically cleaned, ultrasonically cleaned, solvent wiped, roughened, plasma cleaned or etched, exposed to chemical vapor deposition, treated with an adhesion promoter, plated, anodized, annealed, coated or any combination thereof. The substrate can be treated using any of the previously described methods before applying the coating composition, such as by immersing the substrate in a cleaning agent and / or deoxidizer bath before applying the coating composition. The substrate can also be plated before applying the coating composition. As used herein, "plating" refers to depositing metal on the surface of the substrate. The substrate can also be 3D printed.

[0077] As described above, the substrate may include an energy storage device, such as a battery or a battery component. For example, the battery may be an electric vehicle battery, and the battery assembly may be an electric vehicle battery assembly. A "battery assembly" may be any component in a battery, such as a lithium-ion battery. The battery assembly may include, for example, electrodes, battery cells, battery housings, battery modules, battery packs, battery boxes, battery cell housings, battery pack housings, battery covers and trays, thermal management systems, battery housings, module housings, module racks, battery side panels, battery cell housings, cooling modules, cooling tubes, cooling fins, cooling plates, busbars, battery frames, electrical connections, metal wires, copper or aluminum conductors or cables. Other energy storage devices include, but are not limited to, fuel cells or hydrogen tanks.

[0078] Therefore, the present disclosure further relates to an article coated at least partially with a coating composition of the present disclosure. The coating composition of the present disclosure can be applied to the article in any form (such as a coating composition or a cross-linked expanded self-supporting film or sheet). When the film or sheet is "applied to" and any variant thereof, it means that the film / sheet can be attached to the article, such as by means of an adhesive layer, or positioned in the article or placed in the article, such as adjacent to a fixed or movable element of the article. The article can be a structure. The article can be a vehicle. The article can be a battery component or a battery, such as a lithium-ion battery or other energy storage device. For example, the coating composition of the present disclosure or the cross-linked self-supporting film or sheet can be applied to any structural element of a battery, in particular a lithium-ion battery, to obtain a battery according to the present disclosure. The battery can include an outer wall element and optionally an inner wall element defining a housing, wherein the expanded coating or the cross-linked expanded self-supporting film or sheet is at least partially applied to the outer side and / or inner side of any one of the outer wall elements and / or any side of any one of the inner wall elements (if present). The outer wall and / or inner wall elements may include composite materials, steel, aluminum and / or polycarbonate. The coating composition of the present invention may be particularly suitable for use outside of a battery or other energy storage device that is in contact with or near other coatings that may be flammable (such as electrophoretic coatings). This can prevent or at least minimize the possibility of such coatings catching fire during a thermal runaway event. For example, the composition of the present invention in any form may be placed on the outer wall of a battery box, including a surface in contact with the body of a vehicle.

[0079] Batteries, in particular lithium-ion batteries, can include a battery pack comprising a plurality of individual battery cells, wherein the coating or cross-linked self-supporting film or sheet of the present invention is positioned to thermally insulate at least some of the individual battery cells from each other in an expanded and optionally charred state, such as between two battery cells. In addition, the coating composition or self-supporting film or sheet can be applied to or placed adjacent to the housing wall and internal partition wall of the battery pack, as described above.

[0080] It may be desirable to use one or more additional flame retardant materials and / or fire mitigation devices inside the battery and / or contacting the outside of the battery. For example, insulating or high-strength materials may be wrapped around the battery cells or otherwise positioned between the battery cells, or around the periphery or interior of the battery housing. Examples of such materials include fiberglass, mineral wool, silica / silicon dioxide fibers, alumina, Kevlar, Nomex, calcium silicate or calcium silicate fibers; these materials may, for example, be in sheet or other self-supporting form. Foams such as polyurethane / polyurea foams with flame retardants may also be used. Physical barriers such as cooling sheets inserted between battery cells, mica sheets, aerogel blankets, and / or mineral / glass / carbon fiber blankets may also be used.

[0081] In order to provide fire protection for articles containing batteries and their users, in the present disclosure, a curable coating composition or a cross-linked self-supporting film or sheet is applied to a portion of the article between the battery and the article near the battery to isolate the article from the battery. In such cases, conventional batteries or batteries according to the present disclosure can be used. For example, the article can be a mobile phone, a tablet computer, or a laptop computer.

[0082] Optionally, the article can be a vehicle such as a hybrid or electric car, a bus or a truck. In such vehicles, the batteries (especially lithium-ion batteries, due to their weight) are usually positioned as a flat battery pack under the floor portion of the vehicle body (e.g., a car body). In such cases, the coating (including a self-supporting film or sheet) of the present disclosure can be applied to the floor portion of the vehicle between the battery and the vehicle body near the battery. If a battery thermal runaway or battery fire occurs, the car body, especially the passenger compartment, will be protected by the coating layer / film / sheet of the present disclosure so that the battery box will resist the flame, and any fire in the battery box will not spread into the passenger compartment, and the temperature rise of the passenger compartment will be limited for an extended period of time, so that passengers can safely escape the vehicle in the event of such an accident.

[0083] It may also be desirable to apply a fire-retardant electrophoretic paint coating to the vehicle, particularly in contact with or adjacent to the battery. Examples include anionic or cationic electrodeposition coatings. "Fire-retardant electrophoretic paint" as used herein refers to an electrophoretic paint layer deposited from an electro-depositable composition, the composition comprising thermally conductive, electrically insulating pigments, flame retardant pigments, inorganic plate-like pigments (such as layered silicate pigments). The fire-retardant electrophoretic paint may have any suitable pigment to binder (P: B) ratio, and may optionally have a P: B ratio of 0.2: 1 or higher, such as 0.4: 1 or higher, such as 0.5: 1 or higher, up to 2.0: 1. Compared to electro-depositable coatings that do not include flame retardant pigments or have lower pigment content, these coatings are less likely to be flammable due to their use of flame retardant pigments or high pigment content. Suitable examples include those disclosed in: U.S. Patent No. 10,697,081; U.S. Publication No. 2023 / 044601A1; International Publication No. 2021 / 127327A1; and International Publication No. 2022 / 133202A1. Flame retardant adhesives, sealants, gap fillers, potting agents, and encapsulants, such as those formed from compositions comprising flame retardants, may also be used. As used herein, "flame retardant" refers to a material that slows or prevents the spread of a fire or reduces its intensity. The flame retardant can be obtained in powder form, which can be mixed with a composition, foam, or gel, which can form a coating on a substrate surface, and such a coating can act as a flame retardant. Suitable examples include those disclosed in: International Publication No. 2021 / 211722A1, paragraphs 57-309; International Publication No. 2021 / 211183A1, paragraphs 44-178; International Publication No. 2021 / 211184A1, paragraphs 52-252; International Publication No. 2021 / 211694A1, paragraphs 60-299; PCT Application No. PCT / 23 / 67964, paragraphs 44-183; Provisional Application No. 63 / 505,645, paragraphs 51-252; Provisional Application No. 63 / 497,303, paragraphs 31-141; and Provisional Application No. 63 / 477,568, paragraphs 58-223.

[0084] The compositions of the present disclosure can be applied by any standard means in the art, such as electrocoating, spraying, electrostatic spraying, dip-rolling, brushing, etc., including robotic application. Application can be by precision spraying, where the composition is sprayed onto specific portions of the substrate without overspray.

[0085] As used herein, unless otherwise expressly stated, all numbers such as those representing values, ranges, amounts or percentages may be interpreted as beginning with the word "about", even if the term does not appear explicitly. Moreover, all numerical ranges described herein are intended to include all sub-ranges described herein. The singular encompasses the plural, and vice versa. For example, although "a" film-forming component, "a" film-forming resin, "a" phosphoric acid source, "a" boric acid source, "a" flame retardant, "a" gas source, etc. are mentioned herein, one or more of each of these and any other components may be used. In addition, as used herein, the term "polymer" means both prepolymers, oligomers, and homopolymers and copolymers; the prefix "poly" refers to two or more. When a range is given, any endpoints within those ranges and / or the numbers within those ranges may be combined within the scope of the present disclosure. "Including", "such as", "for example" and similar terms mean "including / such as / for example but not limited to". The terms "acrylic acid" and "acrylate" are used interchangeably (unless doing so would change the intended meaning) and include acrylic acid, anhydride and its derivatives, lower alkyl substituted acrylic acid, such as C 1 -C 2 Substituted acrylic acid, such as methacrylic acid, methacrylic acid, etc., and C 1 -C 6 Alkyl esters and hydroxyalkyl esters unless expressly stated otherwise.

[0086] Examples

[0087] The following examples are intended to illustrate the present disclosure and should not be construed as limiting the present disclosure in any way.

[0088] Examples

[0089] Coating formulations 1 and 2 were prepared using the ingredients shown below. The base of each coating formulation was prepared by dispersing all components under a disperser at high speed until the particle size in the formulation was less than 200 microns. The hardener of each coating formulation was prepared by dispersing all components under a disperser at high speed until the particle size in the formulation was less than 200 microns. The dispersion speed and dispersion plate size were 2000 rpm and 80 mm respectively, with a container diameter of 180 mm. Immediately before application, the base and hardener were mixed in the relative amounts shown in the table below. The base and hardener were mixed by a mixer or a spatula until the color of the mixture became uniform and there were no lumps. The coating formulations were applied separately by airless spray on 150x 75x 1.2 mm steel panels covered with 25±5 microns of electrophoretic coating to a thickness of 600±100 microns. The coated panels were tested in a torch flame at 1450°C ± 50°C with a heat output of >5kW on the uncoated side for 5 minutes, after which, if the coating did not ignite, the char was cut away to expose the substrate to determine if the cut coating ignited after exposure to the flame.

[0090] Formulation 1: Comparative Example

[0091] Formulation 1 - Base (base:hardener = 4:1)

[0092]

[0093]

[0094] 1 Hexion

[0095] 2 Gabriel performance products 3 Nippon electric glass

[0096] 4 Elementis Specialties

[0097] 5 Clariant AG

[0098] 6 The Chemours Company LLC

[0099] Formulation 1-curing agent (base material:curing agent=4:1)

[0100]

[0101] 7 Huntsman

[0102] 8 Huntsman

[0103] 9 BASF

[0104] 10 Allnex

[0105] Formulation 2:

[0106] Formulation 2 - base material (base material: curing agent = 4:1)

[0107]

[0108]

[0109] 11 Lehmann&Voss&Co.KG

[0110] Formulation 2-curing agent (base material:curing agent=4:1)

[0111]

[0112] Formulation 1, which contained no magnesium hydroxide or other flame retardant, ignited when the char just above the flame affected area was moved onto the substrate. Formulation 2, in which about 67% of the APP was replaced with magnesium hydroxide, did not ignite after 5 minutes of flame exposure or cutting of the char and continued flame exposure.

[0113] While specific examples of the present disclosure have been described above for purposes of illustration, it will be apparent to those skilled in the art that various changes may be made in the details of the disclosure without departing from the present disclosure as defined in the appended claims.

Claims

1. A flame retardant coating composition comprising: a) film-forming components; b) a phosphoric acid source; c) TiO2; d) flame retardants; as well as e) Gas source; wherein the film-forming component is present in an amount of 10 wt % to 50 wt %, such as 15 wt % to 40 wt %; the phosphoric acid source is present in an amount of 15 wt % to 50 wt %, such as 20 wt % to 40 wt % or 15 wt % to 35 wt %, TiO2 is present in an amount of 3 wt % to 20 wt %, such as 3 wt % to 8 wt % or 5 wt % to 15 wt %, the flame retardant is present in an amount of 10 wt % to 40 wt %, such as 15 wt % to 30 wt %, and the gas source is present in an amount of 2 wt % to 20 wt %, such as 2 wt % to 5 wt %, wherein the wt % is based on the total solid weight of the composition.

2. A coating composition according to claim 1, wherein the flame retardant is present in an amount of 10 wt% or more, such as 15 wt% or more.

3. The coating composition according to any preceding claim, further comprising a boric acid source, a silica source, a zinc source, an acid source, a metal oxide, titanium isopropoxide, a carbon source, an inorganic filler, glass fibers and / or mineral fibers, a rheological additive, an organic solvent, a pigment, a foam stabilizer, and combinations thereof.

4. A coating composition according to any preceding claim, further comprising one or more additives in a total amount of 2 wt% to 20 wt%, wherein the wt% is based on the total solids weight of the composition.

5. A coating composition according to any preceding claim, wherein the film-forming component comprises an epoxy resin and an amine crosslinker, the phosphoric acid source comprises ammonium phosphate, the flame retardant comprises a hydrated metal oxide, and the gas source comprises melamine, urea and / or expandable graphite.

6. A coating composition according to any preceding claim, wherein the composition is substantially free, essentially free and / or completely free of one or more of: a boric acid source; an alkylphosphonic acid; melamine; ethylenically unsaturated monomer residues such as those from (meth)acrylic acid and / or styrene; surfactants, including but not limited to nonionic surfactants; silicates, including but not limited to layered silicates and aluminum silicates; and piperazine salts.

7. A self-supporting film or sheet formed from a coating composition according to any preceding claim.

8. A coating or self-supporting film or sheet according to any preceding claim, wherein the coated film / sheet is flame retardant as determined according to the Thermal Runaway Test.

9. A method for coating a substrate comprising applying a coating composition or a film or a sheet according to claims 1 to 8 to at least a portion of the substrate.

10. The method of claim 9, wherein the substrate comprises: Metal, such as aluminum or steel; or plastic, such as polycarbonate.

11. A substrate coated according to the method of any one of claims 9 or 10.

12. An article comprising the substrate according to claim 11.

13. The article of claim 12, wherein the article comprises a battery, such as a lithium-ion battery.

14. The article of claim 13, wherein the battery comprises: an outer wall member defining a housing; and optional inner wall elements, wherein the coating composition or film or sheet is at least partially applied to the outside and / or inside of any of the outer wall elements, and / or is at least partially applied to either side of any of the inner wall elements, if the inner wall elements exist.

15. The article of claim 14, wherein any of the outer wall elements and / or inner wall elements comprise a composite material, steel, aluminum and / or polycarbonate.

16. The article according to any one of claims 13 to 15, further comprising one or more additional flame retardant materials and / or fire mitigation devices inside and / or outside the battery, such as: insulation materials, high strength materials such as glass fibers, mineral wool, silica / silica fibers, alumina, Kevlar, Nomex, calcium silicate or calcium silicate fibers; foams such as polyurethane / polyurea foams with flame retardants; and / or physical barriers such as cooling sheets, mica boards, aerogel blankets and / or blankets containing mineral / glass / carbon fibers.

17. The article of any one of claims 16, wherein the article comprises a vehicle.

18. A vehicle according to claim 17, wherein the vehicle has a surface at least partially coated with: a fire retardant electrophoretic paint, such as a fire retardant electrophoretic paint deposited from an electrodepositable composition comprising a flame retardant pigment, an inorganic platelet pigment such as a layered silicate pigment and / or having a pigment to binder (P:B) ratio of 0.4:1 or higher, such as 0.5:1 or higher, up to 2.0:1; and / or a flame retardant adhesive, sealant, gap filler, potting agent and / or encapsulant, such as those formed from a composition comprising a flame retardant.

19. The article of claim 12, wherein the article comprises a structure.

20. The article of claim 12, wherein the article comprises an energy storage device.

21. A vehicle comprising: A surface at least partially coated with a composition, sheet or film according to any one of claims 1 to 8; and a battery, wherein the composition, sheet or film is located between the surface and the battery.

22. The vehicle of claim 21, wherein the vehicle comprises at least one flammable coating, such as an electrophoretic coating, and the composition, sheet or film is located between the electrophoretic coating layer and the battery.

23. The vehicle of claim 21, further comprising: Fire retardant electrophoretic paints, such as those deposited from an electrodepositable composition comprising a flame retardant pigment, an inorganic platelet pigment such as a layered silicate pigment and / or having a pigment-binder (P:B) ratio of 0.4:1 or higher, such as 0.5:1, up to 2.0:1; and / or flame retardant adhesives, sealants, gap fillers, potting agents and / or encapsulants, such as those formed from compositions comprising a flame retardant.

Images