flame-retardant coating

Abstract

Coating compositions having flame retardant and controlled expansion are disclosed, as are methods for using such compositions and substrates coated therewith.

Description

[Technical Field]

[0001] The present disclosure is directed to flame retardant coating compositions, methods for coating substrates with the compositions, substrates coated with the compositions, and articles comprising the substrates, including energy storage devices. [Background technology]

[0002] Fire-retardant coatings have been used in a variety of structural applications to protect against both cellulose and hydrocarbon fires. Such coatings provide protection by imparting flame retardancy to the coated substrate. Numerous substrates can benefit from such coatings, including structural building components used in commercial and transportation infrastructure, such as hotels, airports, concert halls, offshore sites, chemical plants, oil rigs, and other facilities that would be exposed to extreme heat in the event of a fire. Energy storage devices, such as batteries, including lithium-ion batteries, may also be exposed to such intense heat, making them vulnerable to thermal runaway, during which heat and gases are rapidly released, creating a fire hazard. While traditional single-pack fire-resistant coatings lack excellent weather resistance, two-pack fire-resistant coatings are too viscous to be applied in thin thicknesses. Therefore, improved fire-resistant coatings, including those used on energy storage devices, are desirable. Summary of the Invention

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

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

[0005] The present disclosure is directed to a coating composition comprising: a) a film-forming component; b) a phosphate source; c) TiO; d) a flame retardant; and e) a gas source. The film-forming component may be present in an amount of 10 to 50 wt. %, e.g., 15 to 40 wt. %, the phosphate source may be present in an amount of 15 to 50 wt. %, e.g., 20 to 40 wt. %, the TiO may be present in an amount of 3 to 15 wt. %, e.g., 3 to 8 wt. %, the flame retardant may be present in an amount of 10 to 40 wt. %, e.g., 15 to 30 wt. %, and the gas source may be present in an amount of 2 to 20 wt. %, e.g., 2 to 5 wt. %, all weight percentages being based on the total solids weight of the composition. When a composition is 100% solids, it is understood that the total solids weight of the composition when uncured is the same as the total solids weight when cured, which is typical.

[0006] The present coating compositions can be used to form flame-retardant coatings. A "flame-retardant" coating is one that does not readily ignite. "Flame-retardant," and similar terms, mean that a coating according to the present disclosure, when applied to one side of a 0.8-1.2 mm thick steel panel, cured to a dry film thickness of 600 microns + / - 100 microns, and exposed to 1450 ± 50°C with the uncoated side of the steel at a heat output of >5 kW, will not ignite after 5 minutes of exposure to flame, and further, will not ignite after 5 minutes of exposure to such heat output when the char directly above the flame impact area is severed to expose the substrate (and still be exposed to flame). This test is intended to mimic a thermal runaway event in a battery and is sometimes referred to herein as the "thermal runaway test."

[0007] Coatings deposited from the present coating compositions can also provide thermal insulation to the coated substrate. For example, the present coatings may expand by less than 4 to 20 times their dry film thickness, e.g., less than 15 or less than 10 times, e.g., 5 to 8 times, when exposed to the above-mentioned heat outputs. This expansion is significantly less than the typical expansion of other intumescent coatings under thermal conditions, which typically expand by 20 to 50 times. Thus, a feature of the present disclosure is to provide compositions that have both controlled expansion and flame retardancy, as defined above.

[0008] The coating composition according to the present disclosure is particularly suitable for the surfaces, especially the exterior surfaces, of energy storage devices. For example, when applied to batteries used in electric vehicles, the coating (or a sheet / film made therefrom) can contain a fire within the battery and prevent it from spreading to other parts of the vehicle. For example, when an organic coating, such as an electrocoat, primer, or other coating(s), is deposited on the battery box, the coating can delay, if not prevent, the coating(s) from catching fire. The coating can also be used on substrates treated with inorganic treatments. The thermal insulation of the coating can also reduce heat damage to the exterior 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 is capable of forming a continuous film on a surface upon drying and / or curing. The film-forming component may include, for example, a film-forming resin and a crosslinking agent therefor. Any film-forming composition may be used in accordance with the present invention. Such a resin may react with itself, i.e., undergo a self-crosslinking reaction, or may react with a crosslinking agent to form a film. Such reactions may occur at ambient or elevated temperatures. "Crosslinking agent," curing agent, and similar terms may be used interchangeably herein.

[0010] Any suitable resin or combination of resins can be used for the film-forming component, including, but not limited to, epoxy resins, acrylic resins, polysiloxane resins, polyurethane resins, polyurea resins, polyvinyl resins, phenolic resins, urea-formaldehyde resins, polyimide resins, melamine resins, polyester resins, and cyanate resins, of which 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 the crosslinker. Examples of suitable functional groups include, for example, ketone, hydrazide, carbodiimide, oxazoline, epoxy, amine, vinyl, amide, carbamate, urea, mercaptan, carboxylic acid, (meth)acryloyl, isocyanate, alkoxysilyl, anhydride, hydroxyl, and alkoxy groups, functional groups, and combinations thereof.

[0012] Suitable functional groups capable of reacting with each other include, for example, N-methylamide groups, silicon-bonded hydrolyzable or condensable groups, such as silane groups with chloro, hydroxy, alkoxy, acetoxy, and / or ketoximo groups, ethylenically unsaturated fatty acid groups capable of oxidative drying with atmospheric oxygen, azomethine groups, azetidine groups, and groups capable of thermally reversible Diels-Alder reaction, such as furan / maleimide. When a resin contains functional groups capable of reacting with each other, it is considered self-crosslinking, and the presence of a curing agent is not required for the composition.

[0013] The resin may also contain a combination of functional groups that are capable of reacting with each other (self-crosslinking) and functional groups that are reactive with functional groups on the curing agent. In such cases, the curing agent may be present, and upon curing, two crosslinking mechanisms will occur: a reaction between the functional groups on the crosslinker and the resin, and a self-crosslinking reaction of the resin itself.

[0014] Epoxy resins suitable for use in the present disclosure include at least one polyepoxide. The polyepoxide typically has at least two 1,2-epoxy groups. The epoxy equivalent weight of the polyepoxide can range from 80 to 6000, for example, from 100 to 700. The epoxy compounds can be saturated or unsaturated, cyclic, aliphatic, cycloaliphatic, aromatic, or heterocyclic. They can contain substituent(s) such as halogen, hydroxy, and ether groups.

[0015] Examples of suitable polyepoxides are those having a 1,2-epoxy equivalent weight of two or more, or usually two, i.e., an average of two epoxy groups per molecule. The most commonly used polyepoxides are polyglycidyl ethers of polyphenols such as 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), resorcinol, hydroquinone, benzenedimethanol, phloroglucinol, bisphenol F, and catechol, or polyglycidyl ethers of 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. Examples of aliphatic polyols include, inter alia, trihydroxymethylpentanediol, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, cyclohexanedimethanol, glycerol, trimethylolpropane, hydrogenated bisphenol A, hydrogenated bisphenol F, or polyether glycols such as poly(oxytetramethylene) glycol, poly(oxyethylene) glycol, poly(oxypropylene) glycol, and neopentanediol.

[0016] Another group of suitable epoxy resins includes the polyglycidyl ethers of polycarboxylic acids formed by the reaction of 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-naphthalenedicarboxylic acid, or dimerized linoleic acid. Such resins are commercially available from Hexion Inc. in their EPIKOTE and EPON lines.

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

[0018] Furthermore, according to the present disclosure, it may be advantageous to use flexible polyepoxide resins as the polyepoxy-functional compound of the composition of the present disclosure. These resins are generally essentially 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 (Ludwigshafen, Germany), and rubber-modified polyepoxide resins such as products prepared from polyglycidyl ethers of bisphenol A and acid-functional polybutadienes.

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

[0020] Linear polyesters may be preferred over branched polyesters for use herein. 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] Diols that can be used in making polyesters include alkylene glycols such as ethylene glycol, diethylene glycol, and neopentyl glycol, as well as other diols such as hydrogenated bisphenol A, cyclohexanediol, cyclohexanedimethanol, caprolactone diols, such as the reaction product of epsilon-caprolactone and ethylene glycol, hydroxy-alkylated bisphenols, and polyether glycols such as poly(oxytetramethylene) glycol, poly(oxyethylene) glycol, and poly(oxypropylene) glycol. While diols are preferred, higher-functionality polyols can also be used. Examples include trimethylolpropane, trimethylolethane, pentaerythritol, glycerol, isosorbide, tetramethylcyclobutanediol, and the like, as well as higher molecular weight polyols such as those produced by oxyalkylating lower molecular weight polyols.

[0022] The acid component of the polyester may comprise a monomeric dicarboxylic acid or anhydride having 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, decanedioic acid, dodecanedioic acid, rosin acid, diphenolic acid, gallic acid, and various types of other dicarboxylic acids, such as unsaturated C 18 Diels-Alder adducts of fatty acids are included.

[0023] The polyester may contain small amounts of monobasic acids such as benzoic acid, stearic acid, acetic acid, hydroxystearic acid, and oleic acid. Higher polycarboxylic acids such as trimellitic acid may also be used. Where acids are referred to above, it is understood that the anhydrides of these acids that form the anhydrides can be used in place of the acids. Lower alkyl esters of acids such as dimethyl glutarate and dimethyl terephthalate can also be used.

[0024] According to the present disclosure, the polyesters used to make the epoxy-functional adducts may 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 may be used to prepare the epoxy-functional adducts of flexible acid-functional polyesters and polyepoxides may be selected from those defined above for the polyepoxide-functional component according to the present disclosure.

[0026] Other suitable polyepoxy-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 containing at least one carbon-carbon double bond, where the monomer composition includes 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, vinylcyclohexene oxide, limonene oxide, 2-ethylglycidyl acrylate, 2-ethylglycidyl 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, alpha-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and combinations thereof.

[0028] Additional monomers suitable 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, ... sulfonic acid monomers and / or ethylenically unsaturated phosphorus-containing 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 in preparing the 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 either an acetyl group or an additional nitrile group. Such nitrile monomers include acrylonitrile, methacrylonitrile, alpha-cyanoethyl acrylonitrile, fumaronitrile, and combinations thereof, with acrylonitrile being particularly preferred.

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

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

[0032] Suitable alkyl esters of (meth)acrylic acid include, for example, C1 to C 10 -C1-C alkyl (meth)acrylates, etc. 20Alkyl (meth)acrylates may be mentioned. Examples of such acrylate monomers include n-butyl acrylate, secondary 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. Particularly suitable are (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and combinations thereof.

[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 preferred 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 that can be used to prepare epoxy-functional acrylic resins include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl 2-ethylhexanoate, vinyl stearate, and vinyl esters of versatic acid.

[0036] Ethylenically unsaturated carboxylic acid monomers suitable for preparing epoxy-functional acrylic resins include, for example, monocarboxylic and dicarboxylic acid monomers and monoesters of dicarboxylic acids. Ethylenically unsaturated aliphatic monocarboxylic or dicarboxylic acids or anhydrides containing 3 to 5 carbon atoms are particularly suitable. Examples of monocarboxylic acid monomers include acrylic acid, methacrylic acid, and crotonic acid, while examples of dicarboxylic acid monomers include fumaric acid, itaconic acid, maleic acid, and maleic anhydride. Other suitable ethylenically unsaturated acids include vinyl acetic acid, vinyl lactic acid, vinyl sulfonic acid, 2-methyl-2-propene-1-sulfonic acid, styrene sulfonic acid, acrylamidomethylpropane sulfonic 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 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- Conjugated diene monomers such as octadiene, 7-methyl-3-methylene-1,6-octadiene, 1,3,7-octatriene, 2-ethyl-1,3-butadiene, 2-amyl-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 different polyepoxy-functional compounds, such as three or more, or four or more, in a film-forming component such as any of those disclosed above.

[0039] Suitable polyepoxy-functional compounds for use in accordance with the present disclosure may include, for example, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, resorcinol diglycidyl ether, epoxy phenol novolac resins, epoxy cresol novolac resins, epoxy-functional (poly)siloxanes, epoxy-functional polysulfides, epoxy-functional adducts of acid-functional polyesters, and polyepoxides, such as those described above. Acrylic resins for use in the present disclosure may include, for example, copolymers of one or more alkyl esters of acrylic or methacrylic acid, optionally with one or more other polymerizable ethylenically unsaturated monomers. Useful alkyl esters of acrylic or methacrylic acid include, for example, aliphatic alkyl esters containing 1 to 30, and 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, vinyls and halides such as vinyl chloride and vinylidene fluoride, and vinyl esters such as vinyl acetate.

[0040] Acrylic copolymers can contain hydroxyl functionality, which is often incorporated into the polymer by including one or more hydroxyl-functional monomers in the reactants used to produce the copolymer. Useful hydroxyl-functional monomers typically include hydroxyalkyl acrylates and methacrylates having 2 to 4 carbon atoms in the hydroxyalkyl group, such as hydroxyalkyl acrylates, hydroxyethyl acrylate, hydroxypropyl acrylate, 4-hydroxybutyl acrylate, hydroxy-functional adducts of caprolactone and hydroxyalkyl acrylates, and the corresponding methacrylates, as well as the beta-hydroxyester-functional monomers described below. Acrylic polymers can also be prepared with N-(alkoxymethyl)acrylamides and N-(alkoxymethyl)methacrylamides.

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

[0042] The film-forming resins used in the present disclosure can also include polyurethanes. Among the polyurethanes that can be used are polymer 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, resulting in free hydroxyl groups being present in the product.

[0043] According to the present disclosure, the film-forming component may include, for example, a combination of an epoxy resin and an acrylic resin, or an epoxy resin and a polyurethane resin, as disclosed in US Pat. No. 5,108,832 or US Pat. No. 5,070,119.

[0044] When the film-forming component includes an epoxy resin and a polyamine- and / or polythiol-functional compound as a curing agent, as discussed below, the film-forming component may further include (i) a beta-hydroxy ester of (meth)acrylic acid, (ii) a (meth)acrylate-functional compound different from compound (i), or a combination thereof.

[0045] The beta-hydroxy ester of (meth)acrylic acid can include multiple beta-hydroxy esters of (meth)acrylic ester groups resulting from the reaction of a polyepoxide with (meth)acrylic acid. The polyepoxide can be reacted with (meth)acrylic acid in an epoxy-to-carboxylic acid equivalent ratio of 1:0.1 to 1:1.2, preferably 1:0.5 to 1:1.2, and more preferably 1:1 to 1:1.05. A particularly suitable beta-hydroxy ester of (meth)acrylic acid is the reaction product of EPIKOTE 828 (a reaction product of bisphenol A and epichlorohydrin) with acrylic acid, commercially available from Allnex as EBECRYL 3720.

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

[0047] In addition to or instead of the beta-hydroxyester of (meth)acrylic acid (i), a (meth)acrylate-functional compound (ii) different from compound (i) may be present in the film-forming component. This allows the viscosity of the composition of the present disclosure to be suitably adjusted. Therefore, the optional component (ii) is considered to function as a reactive diluent. The optional (meth)acrylate-functional component (ii) of the present composition may include, for example, poly(meth)acrylates of 1,4-butanediol, neopentyl glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, paraxylene glycol, 1,4-cyclohexanediol, trimethylolethane, trimethylolpropane, pentaerythritol, polyether glycols such as poly(oxytetramethylene) glycol, poly(oxyethylene) glycol, poly(oxypropylene) glycol, and combinations thereof.

[0048] As mentioned above, the film-forming component may also include a crosslinking agent. Any suitable crosslinking agent can be used in accordance with 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 curing agents include, for example, polyamines, such as polyetheramines, polyamides, polyepoxides, aminoplast resins, phenolic resins, polyisocyanates, polythiols, and polyols.

[0049] The curing agent may also be a latent or blocked curing agent, in which 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 at elevated temperatures. A suitable curing agent of this type is, for example, a blocked polyisocyanate. Thus, as used herein, the term polyisocyanate encompasses blocked polyisocyanates and free polyisocyanates. Latent or blocked curing agents are particularly suitable for providing a single-component composition to ensure sufficient storage stability and pot life before application and curing.

[0050] Polyamine curing agents may include, for example, aliphatic polyamines, aromatic polyamines, polyamine amides, polyether amines, such as those commercially available from Huntsman Cooperation (The Woodlands, Texas), polysiloxane amines, polysulfide amines, or combinations thereof. Particularly preferred examples include diethylenetriamine, 3,3-amino-bis-propylamine, triethylenetetramine, tetraethylenepentamine, m-xylenediamine, isophoronediamine, 1,3-bis(aminoethyl)cyclohexane, bis(4-aminocyclohexyl)methane, N-aminoethylpiperazine, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, and diaminodiphenylsulfone, as well as reaction products of polyamines with aliphatic fatty acids, such as the series of materials sold by BASF under the trademark VERSAMID.

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

[0052] Various polyetheramines can also be used as curing agents, such as 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] Various polyamides can also be used as curing agents. Generally, polyamides contain the reaction product of dimeric fatty acids and polyethyleneamines, as well as a small amount of monomeric fatty acids. Dimeric fatty acids are prepared by oligomerization of monomeric fatty acids. The polyethyleneamine can be any higher polyethyleneamine, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, etc., with diethylenetriamine being the most commonly used. The use of polyamides as curing agents 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 can include polysulfide thiols, polyether thiols, polyester thiols, pentaerythritol-based thiols, or combinations thereof. A particularly suitable polythiol compound is THIOPLAST G4, commercially available from Akzo Nobel Functional Chemicals GmbH & Co. KG (Greiz, Germany).

[0055] As mentioned above, when the film-forming resin comprises an epoxy resin, a polyamine, a polythiol compound, or a combination thereof, can be used as a crosslinking agent.

[0056] In the coating compositions of the present disclosure, when an epoxy resin is used, the equivalent ratio of combined functional groups in the film-forming resin, such as epoxy groups, to 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 suitable amount of film-forming components. For example, the coating composition can contain 10% or more by weight of the film-forming components, such as 30% or more by weight, or 40% or more by weight. The coating composition can contain 50% or less by weight of the film-forming components, such as 40% or less by weight, or 20% or less by weight. The coating composition can include the film-forming components in an amount ranging between any of the above-mentioned values, such as 10% to 50% by weight, 15% to 40% by weight, or 20% to 50% by weight. The weight percentages reported herein are based on the total solids weight of the composition unless otherwise indicated.

[0058] The coating composition of the present disclosure further comprises a phosphate source. As used herein, "phosphate source" refers to any phosphorus-containing material, including phosphoric acid, its condensation or dehydration products (including oxides), or salts, esters, amides, or other derivatives of any of the foregoing. Phosphate sources can include a variety of materials, such as, for example, phosphoric acid, monoammonium phosphate and diammonium phosphate, triphenyl phosphate, tris-(2-chloroethyl) phosphate, tri(2-chloroisopropyl) phosphate, phosphorus-containing amides such as phosphorylamide, and melamine pyrophosphate. Preferably, the phosphorus source is a phosphate having the formula (NH4) n+2 P n O 3n+1where n is an integer of at least 2, and preferably n is an integer of at least 50. The compositions of the present disclosure may contain the phosphate source in an amount greater than or equal to 15 wt%, such as greater than or equal to 20 wt%, greater than or equal to 25 wt%, or greater than or equal to 30 wt%, greater than or equal to 35 wt%, or greater than or equal to 40 wt%. The coating composition may contain the phosphate source in an amount less than or equal to 50 wt%, such as less than or equal to 45 wt%, or less than or equal to 40 wt%, or less than or equal to 35 wt%. The coating composition may contain the phosphate source in an amount ranging between any of the above-mentioned values, such as 15 to 50 wt%, e.g., 20 to 40 wt%, or 15 to 35 wt%. The weight percentages reported herein are based on the total solids weight of the composition. Phosphorus is believed to function as a charcoal promoter in the present composition.

[0059] The compositions of the present disclosure further comprise titanium dioxide (TiO). Compositions according to the present disclosure may comprise TiO in an amount greater than or equal to 3 wt%, such as greater than or equal to 6 wt%, or greater than or equal to 7 wt%, or greater than or equal to 8 wt%, or greater than or equal to 9 wt%, or greater than or equal to 10 wt%. The coating compositions may comprise TiO in an amount less than or equal to 20 wt%, such as less than or equal to 15 wt%, or less than or equal to 18 wt%, or less than or equal to 17 wt%, or less than or equal to 15 wt%, or less than or equal to 13 wt%, or less than or equal to 10 wt%. The compositions may comprise TiO in an amount ranging between any of the above-mentioned values, such as from 3 to 20 wt%, such as from 3 to 8 wt%, or from 5 to 15 wt%. The weight percentages reported above are each based on the total solids weight of the composition. It will be understood that due to the presence of TiO (and optionally other pigment(s) discussed below), the compositions of the present disclosure are opaque, i.e., they 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 upon heating, such as hydrated metal oxides, including Al(OH)3 and Mg(OH)2. The coating composition may comprise the flame retardant in an amount greater than 10% by weight, such as greater than 15% by weight or greater than 20% by weight. The coating composition may comprise the flame retardant in an amount less than 50% by weight, such as less than 35% by weight or less than 30% by weight. The composition may comprise the flame retardant in an amount ranging between any of the above-mentioned values, such as 10 to 40% by weight, or 15 to 30% by weight. The weight percentages reported above are based on the total solids weight of the composition. The use of flame retardants in amounts less than 10% by weight significantly increases the likelihood that the coating will ignite.

[0061] The coating composition further includes a gas source. "Gas source" refers to a compound that provides an inflation gas upon thermal decomposition. The inflation gas causes the composition to foam and inflate when exposed to high temperatures or flames. As a result of this expansion, a thick, multicellular char forms, which serves to insulate and protect the underlying substrate. Any suitable source of inflation gas that can be used in the coating composition of the present disclosure is a nitrogen-containing material. Examples of suitable nitrogen-containing materials include melamine, salts of phosphoric acid, guanidine, methylated melamine, hexamethoxymethylmelamine, urea, dimethylurea, melamine pyrophosphate, dicyandiamide, guanylurea phosphate, and glycine. Other conventional inflation gas sources, such as materials that liberate carbon dioxide, can also be used. Examples are alkaline earth metals such as calcium carbonate or magnesium carbonate. Compounds that release water vapor when decomposed upon heating, such as calcium hydroxide, magnesium hydroxide, or aluminum hydroxide, can also be used as expandable graphite. Other examples of such compounds are borate sources, such as boric acid, and boric acid derivatives, such as borate esters and metal borates. Gas sources such as melamine may be used in the expanding compositions of the present disclosure in amounts greater than or equal to 2% by weight, such as greater than or equal to 3% by weight, or greater than or equal to 4% by weight. Compositions according to the present disclosure may contain the gas source in an amount of, for example, less than or equal to 20% by weight, less than or equal to 10% by weight, less than or equal to 8% by weight, less than or equal to 7% by weight, or less than or equal to 5% by weight. The composition may contain the gas source in an amount ranging from any of the above-mentioned values, such as from 2 to 20% by weight, e.g., from 2 to 5% by weight. Each reported weight percentage is based on the total solids weight of the composition.

[0062] The coatings of the present disclosure may contain one or more additional additives suitable for use in intumescent coatings. Examples of such additives include borate sources, aluminum sources, silica sources, zinc sources, acid sources, metal oxides such as prehydrolyzed tetraethyl orthosilicate, titanium isopropoxide, carbon sources, inorganic fillers, glass 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, "borate source" refers to any boron-containing material containing boric acid, its condensation or dehydration products (including oxides), or any salt or ester of any of the foregoing. Suitable borate sources include, for example, ammonium pentaborate, boric acid, zinc borate such as metal borates, boron oxide, borates such as sodium borate, potassium borate, and ammonium borate, borate esters such as butyl borate or phenyl borate, and combinations thereof. Suitable aluminum sources include, for example, aluminum hydroxide, aluminum oxide (alumina), aluminum chloride, aluminum salts, and combinations thereof. For example, the aluminum source may include aluminum hydroxide and / or aluminum oxide. As used herein, "silica source" refers to any silicon-containing material containing polysiloxane, silane, silicic acid, their condensation or dehydration products (including oxides), or any salt or ester of any of the foregoing. Suitable silica sources include, for example, fumed silica or quartz, such as those having a particle size of less than 150 μm, or silica-containing materials such as bentone or kaolin.

[0064] When used, the borate source can be used in any suitable amount, such as at or above 5 wt%, for example at or above 6 wt%, for example at or above 7 wt%, for example at or above 8 wt%, for example at or above 9 wt%, for example at or above 10 wt%. The coating composition can include the borate source in an amount of at or below 20 wt%, such as at or below 19 wt%, or at or below 18 wt%, or at or below 15 wt%. The coating composition can include the borate source in an amount ranging between any of the above-mentioned values, such as 5 wt% to 20 wt%, or 6 wt% to 15 wt%, or 9 wt% to 15 wt%. When used, the compositions of the present disclosure can contain a water-release source in any suitable amount, for example, greater than or equal to 0.1% by weight, for example, greater than or equal to 0.2% by weight, or greater than or equal to 0.3% by weight, or greater than or equal to 0.5% by weight, or greater than or equal to 1% by weight, or greater than or equal to 3% by weight, or greater than or equal to 5% by weight. The expanding compositions of the present disclosure can contain a silica source in any suitable amount, for example, greater than or equal to 0.1% by weight, for example, greater than or equal to 0.2% by weight, or greater than or equal to 0.3% by weight, greater than or equal to 0.4% by weight, or greater than or equal to 0.5% by weight. The coating composition may include the silica source in an amount of 5 wt. % or less, such as at or below 3 wt. %, or at or below 2 wt. %, or at or below 1 wt. %, or at or below 0.8 wt. %. The composition may include the silica source in an amount ranging between any of the above-mentioned values, such as 0.1 to 5 wt. %, such as 0.4 to 1 wt. %. The weight percentages reported above are each based on the total solids weight of the composition.

[0065] The optional zinc source can include a variety of materials. It is believed that the zinc material may contribute to the formation of small cell structures in the char. The small cells in the char may provide better insulation for the substrate, better maintain the integrity of the char, and adhere to the substrate. Therefore, cracking and breakage of the char from the substrate are minimized, providing greater protection for the underlying substrate. Examples of suitable zinc source materials include zinc oxide, zinc salts such as zinc borate and zinc phosphate, zinc carbonate, and 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 of the components of the present composition may serve more than one function in the composition. That is, a single material may be the source of more than one of the listed components of the composition. For example, melamine pyrophosphate may provide a source of both phosphorus and inflation gas, zinc borate may provide a source of zinc and borate, and zinc phosphate may provide a source of zinc and phosphate.

[0068] The optional reinforcing filler may be selected from a number of conventionally used materials, including fibrous and platelet reinforcing agents, which may be more suitable than other fillers. Examples of fibrous reinforcing agents include glass fiber, ceramic fibers such as aluminum oxide / silicon oxide, graphite fiber, mineral fiber, and basalt fiber. Platelet reinforcing agents include hammer mill glass flake, mica, and wollastonite. Other suitable fillers include metal oxides, clay, talc, silica, diatomaceous earth, Lapinus fiber, and various pigments. It is believed that the reinforcing filler helps control the expansion of the fire-resistant composition before and during char formation so that the resulting char is firm and uniform. When present, reinforcing fillers such as glass fiber and / or mineral fiber are typically present in the composition in an amount of 5.0% by weight or less, e.g., 4% by weight or less, e.g., 3% by weight or less, based on the total solids weight of the expanded composition. Compositions according to the present disclosure may include reinforcing fillers in amounts at or above 0.1 wt%, such as at or above 0.2 wt%, at or above 0.5 wt%, or at or above 1 wt%. The compositions may include reinforcing fillers in amounts ranging between any of the above-mentioned values, such as 0.1 wt% to 5.0 wt%, or 1 wt% to 4 wt%. The reported weight percentages are each based on the total solids weight of the composition.

[0069] In addition to TiO, the compositions of the present disclosure may also contain various conventional additives, such as rheological additives, organic solvents, foam stabilizers, pigments, and the like. These ingredients are optional and can be added in various amounts. Typically, when additional additives are used, they are present in a total amount of at or above 1 wt%, such as at or above 2 wt%, or at or above 5 wt%, or at or above 10 wt%. When used, additional additives may be present in compositions according to the present disclosure in an amount of at or below 20 wt%, such as at or below 15 wt%, or at or below 12 wt%. The compositions may contain optional additional additives in amounts ranging between any of the above-mentioned values, such as at or above 20 wt%, such as at or above 20 wt%, or at or below 15 wt%, such as at or above 5 wt%. The weight percentages reported are each based on the total solids weight of the composition.

[0070] It may also be desirable for the coating compositions of the present disclosure to specifically exclude certain chemicals or ingredients. For example, the compositions may be substantially free, essentially free, or completely free of one or more of the following: borate sources, alkyl phosphate(s), ethylenically unsaturated monomer residues such as those derived from melamine, (meth)acrylic acid, and / or styrene, surfactants including but not limited to nonionic surfactants, silicates including but not limited to layered silicates and aluminum silicate(s), and piperazine salt(s). As used in this context, "substantially free" means that the composition contains 2% by weight or less of any of these compounds, "essentially free" means that the composition contains 1% by weight or less of any of the compounds, and "completely free" means that the compound, if present, contains only trace amounts that would be present, for example, as an impurity in another compound.

[0071] The composition can be either a one-component ("1K") or a multi-component composition, such as a two-component ("2K") or more-component composition. 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. A 1K composition can be applied to a substrate and cured by any conventional means, such as heat, forced air, etc. The composition can also be multi-component, which will be understood as a composition in which the various components are kept separate until just prior to application. The composition can be thermoplastic or thermosetting. For example, the composition can be packaged as a 2K system, with the film-forming resin in a first package (A) and the curing agent therefor in a second package (B), whereby all of the other components used in the coating composition are used in any combination in package (A), or in package (B), or both, or some or all can be in one or more additional packages (C). The individual packages are mixed before using the expanding composition.

[0072] The coating composition of the present disclosure can be in the form of a thick material such as a mastic. The composition is solvent-free and is particularly suitable for spray application. If desired, thinning can be achieved with various conventional solvents such as xylene, methylene chloride, or 1,1,1-trichloroethane.

[0073] The coating compositions of the present disclosure can be applied to provide various dry film thicknesses as desired. Suitable dry film thicknesses can range from 10 to 20,000 microns, e.g., 50 to 5000 microns, e.g., 100 to 2000 microns. The desired dry film thickness ("DFT") can vary depending on the application. For use in building structural components, a DFT in the range of 200 to 20,000 microns, such as 300 to 1000 microns or 3000 to 15000 microns, can be suitable. For use in lithium batteries, a DFT in the range of 200 to 5000, e.g., 200 to 1000, e.g., 600 + / - 100 microns, can 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 then be cured to form a crosslinked, expanded, self-supporting film or sheet. Generally, the curable composition of the present disclosure can be formed into a film or sheet by any technique known to those skilled in the art, such as by impregnating a mesh with the coating through a casting process. The film or sheet can be cured to form a crosslinked, self-supporting film or sheet, and then applied to a substrate. It is also within the scope of the present disclosure for the uncured film or sheet to be applied to a substrate after the forming step and then subsequently cured to obtain a crosslinked, expanded layer according to the present disclosure. The film or sheet can be applied to the substrate through an adhesive. Thus, as used herein, when referring to a substrate "coated with" the present composition or similar terms, this includes coating by application of a film and / or sheet formed from the composition(s).

[0075] The composition and self-supporting film or sheet can be applied to, for example, automotive substrates, marine substrates, industrial substrates, heavy machinery, packaging substrates, lumber, wood flooring and furniture, apparel, electronics including consumer electronics, including housings and circuit boards, such as housings for computers, notebooks, smartphones, tablets, televisions, game consoles, computer equipment, computer accessories, MP3 players, etc., glass and transparent films, sporting goods including golf balls, 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 and coiled metal sheets that are coiled, uncoiled for coating, and then recoiled for shipping to manufacturers. Non-metallic substrates include polymeric compounds, plastics, polyesters, polyolefins, polyamides, cellulosics, polystyrene, polyacrylics, poly(ethylene naphthalate), polypropylene, polyethylene, nylon, EVOH, polylactic acid, other "green" polymeric substrates, poly(ethylene terephthalate) ("PET"), polycarbonate, polycarbonate acrylobutadiene styrene ("PC / ABS"), SMC, carbon fiber, polyamides, wood, veneers, wood composites, particle board, medium density fiberboard, cement, stone, glass, paper, cardboard, textiles, both synthetic and natural leather, and the like. The substrate may be part of a structure or part of a vehicle. As used herein, "structure" refers to buildings, bridges, transportation infrastructure, oil rigs, oil platforms, water towers, power transmission towers, support structures, wind turbines, walls, piers, docks, levees, dams, shipping containers, trailers, and any portion of any metal structure exposed to a corrosive environment. As used herein, "vehicle" refers in its broadest sense to all types of vehicles, including, but not limited to, cars, trucks, buses, tractors, harvesters, heavy equipment, vans, golf carts, motorcycles, bicycles, rail cars, subway cars, airplanes, helicopters, boats of all sizes, and the like.

[0076] The substrate may be a substrate that has already been treated in some manner to impart visual and / or color effects. For example, the substrate may be treated with alkaline cleaning, deoxidation, mechanical cleaning, ultrasonic cleaning, solvent wiping, roughening, plasma cleaning or etching, exposure to chemical vapor deposition, treatment with an adhesion promoter, plating, anodizing, annealing, cladding, or any combination thereof, before application of the coating composition. The substrate may be treated using any of the aforementioned methods before application of the coating composition, such as by immersing the substrate in a cleaner bath and / or a deoxidizer bath before application of the coating composition. The substrate may also be plated before application of the coating composition. As used herein, "plating" refers to the deposition of a metal over the surface of a substrate. The substrate may also be 3D printed.

[0077] As discussed above, the substrate may comprise an energy storage device such as a battery or battery component. The battery may be, for example, an electric vehicle battery, and the battery component may be an electric vehicle battery component. A "battery component" may be any component found in a battery, such as a lithium-ion battery. Battery components may include, for example, electrodes, battery cells, battery shells, battery modules, battery packs, battery boxes, battery cell casings, pack shells, battery lids and trays, thermal management systems, inverters, battery housings, module housings, module racking, battery side plates, battery cell enclosures, cooling modules, cooling tubes, cooling fins, cooling plates, bus bars, battery frames, electrical connections, metal wires, or copper or aluminum conductors or cables. Other energy storage devices include, but are not limited to, fuel cells or hydrogen tanks.

[0078] Accordingly, the present disclosure is further directed to an article at least partially coated with the coating composition of the present disclosure. The coating composition of the present disclosure can be applied to an article in any form, such as a coating composition or a crosslinked, expanded, self-supporting film or sheet. When referring to a film or sheet, "applied to" and any variations thereof mean that the film / sheet can be attached to the article, such as by an adhesive layer, or positioned or disposed within the article, such as adjacent to a fixed or movable member 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 or crosslinked, self-supporting film or sheet of the present disclosure can be applied to any structural element of a battery, particularly a lithium-ion battery, to obtain a battery according to the present disclosure. The battery can include an outer wall element defining a housing, and optionally an inner wall element, and the expanded coating or crosslinked, expanded, self-supporting film or sheet, if present, is applied at least partially to the outer and / or inner sides of any of the outer wall elements and / or any side of any of the inner wall elements. The exterior and / or interior wall elements may comprise, for example, composite materials, steel, aluminum, and / or polycarbonate. The coating composition may be particularly suitable for use on the exterior of batteries or other energy storage devices that are in contact with or in close proximity to other coatings, such as electrophoretic coatings, that may be flammable. This can prevent or at least minimize the possibility of such coatings catching fire during a thermal runaway event. For example, the composition in any form may be disposed on the exterior wall of a battery box, including the surface that is in contact with the vehicle body.

[0079] Batteries, particularly lithium ion batteries, may include battery packs with multiple individual battery cells, with the present coatings or crosslinked self-supporting films or sheets positioned to insulate at least some of the individual battery cells from one another in the expanded and, optionally, carbonized state, such as between two battery cells. Additionally, the coating compositions or self-supporting films or sheets may be applied or disposed adjacent to the housing walls and internal dividing walls of the battery pack, as discussed above.

[0080] It may be desirable to use one or more additional flame-retardant materials and / or fire mitigation measures within the battery and / or on the exterior of the battery. For example, insulating or high-strength materials may be wrapped or otherwise positioned between the battery cells or around or within the battery housing. Examples of such materials include fiberglass, mineral wool, silica / silica fiber, alumina, Kevlar, Nomex, calcium silicate, or calcium silicate fiber, which may be in sheets or other self-supporting forms, for example. Foams, such as polyurethane / polyurea foams with flame retardants, may also be used. Physical barriers, such as cooling fins sandwiched between battery cells, mica boards, aerogel blankets, and / or mineral / glass / carbon fiber-containing blankets, may also be used.

[0081] It is also within the scope of the present disclosure to apply a curable coating composition or a crosslinked self-supporting film or sheet to a portion of the article adjacent to the battery between the battery and the article to insulate the article from the battery, to provide fire protection to the article and its user. In such cases, conventional batteries or batteries according to the present disclosure can be used. The article can be, for example, a cell phone, tablet, or laptop computer.

[0082] Alternatively, the article may be a vehicle such as a hybrid or electric car, bus, or truck. In such vehicles, due to the weight of the batteries, it is common for batteries, particularly lithium-ion batteries, to be positioned as a flat battery pack beneath the vehicle body, e.g., the floor of the vehicle body. In such cases, a coating of the present disclosure, including a self-supporting film or sheet, may be applied to the vehicle floor adjacent to the battery, between the battery and the vehicle body. In the event of battery thermal runaway or battery fire, the vehicle body, particularly the passenger cabin, will be protected by the coating layer / film of the present disclosure, such that the battery box will withstand the flames and any fire inside the battery box will not spread to the passenger cabin, limiting the temperature rise in the passenger cabin for an extended period of time so that passengers can safely escape from the vehicle in the event of such an event.

[0083] It may also be desirable to apply a fire-resistant ecoat coating to a vehicle, particularly to areas in contact with or adjacent to a battery. Examples include anionic or cationic electrodepositable coatings. As used herein, "fire-resistant ecoat" refers to an ecoat layer deposited from an electrodepositable composition containing a thermally conductive, electrically insulating pigment, a flame-retardant pigment, and an inorganic platelet-like pigment, such as a phyllosilicate pigment. The fire-resistant ecoat coating may have any suitable pigment-to-binder (P:B) ratio, optionally at or above 0.2:1, e.g., at or above 0.4:1, e.g., at or above 0.5:1, up to a P:B ratio of 2.0:1. Due to the use of flame-retardant pigments or high pigment content, these coatings may be less flammable than electrodepositable coatings that do not contain flame-retardant pigments or have lower pigment content. Suitable examples include those disclosed in U.S. Patent No. 10,697,081, U.S. Patent Application Publication No. 2023 / 044601A1, WO 2021 / 127327A1, and WO 2022 / 133202A1. Flame-retardant adhesives, sealants, gap fillers, pottants, and encapsulants can also be used, such as those formed from compositions containing a flame retardant. As used herein, "flame retardant" refers to a material that slows or stops the spread of fire or reduces its intensity. Flame retardants can be available as powders that can be mixed with compositions, foams, or gels that can form coatings on substrate surfaces, and such coatings can function as flame retardants.Suitable examples include those disclosed in WO 2021 / 211722A1, pars. 57-309, WO 2021 / 211183A1, pars. 44-178, WO 2021 / 211184A1, pars. 52-252, WO 2021 / 211694A1, pars. 60-299, PCT Application No. PCT / 23 / 67964, pars. 44-183, U.S. Provisional Patent Application No. 63 / 505,645, pars. 51-252, U.S. 63 / 497,303, pars. 31-141, and U.S. 63 / 477,568, pars. 58-223.

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

[0085] As used herein, unless expressly specified otherwise, all numbers, such as those representing values, ranges, amounts, or percentages, may be read as if preceded by the word "about," even if the term does not explicitly appear. Also, any numerical ranges described herein are intended to include all subranges subsumed therein. The singular encompasses the plural, and vice versa. For example, this specification refers to "a" film-forming component, "a" film-forming resin, "a" phosphate source, "a" borate source, "a" flame retardant, "a" gas source, etc., but one or more of each of these and any other components can be used. Also, as used herein, the term "polymer" is meant to refer to prepolymers, oligomers, and both homopolymers and copolymers, and the prefix "poly" refers to two or more. When ranges are given, any endpoints of those ranges and / or any numerical values within those ranges can be combined with the ranges of the present disclosure. The terms "including," "such as," "for example," and similar terms mean "including, but not limited to, such as." The terms "acrylic" and "acrylate" are used interchangeably (except where doing so changes the intended meaning) and, unless otherwise specified, include acrylic acid, anhydrides, and derivatives thereof, lower alkyl substituted acrylic acids, e.g., C1-C2 substituted acrylic acids such as methacrylic acid, methacrylic acid, and C1-C6 alkyl and hydroxyalkyl esters thereof. [Example]

[0086] The following examples are intended to illustrate the present disclosure and should not be construed as limiting the disclosure in any way.

[0087] Example Coating Formulations 1 and 2 were prepared using the ingredients listed below. The base for each coating formulation was prepared by dispersing all components in a high-speed dispersing machine until the particle size in the formulation was less than 200 microns. The hardener for each coating formulation was prepared by dispersing all components in a high-speed dispersing machine until the particle size in the formulation was less than 200 microns. The dispersing speed and dispersing machine plate size were 2000 rpm and 80 mm, respectively, with a container diameter of 180 mm. Just before application, the base and hardener were mixed in the relative amounts shown in the table below. The base and hardener were mixed with a mixer or spatula until the mixture was homogeneous in color and free of lumps. Each coating formulation was applied by airless spray application to a thickness of 600 ± 100 microns onto a 150 x 75 x 1.2 mm steel panel covered with a 25 ± 5 micron cataphoresis coating. Coated panels were tested on the uncoated side against a 1450 ± 50°C torch fire for 5 minutes with a heat output of >5 kW, and then, if the coating did not otherwise ignite, the char was cut to expose the substrate to determine whether the cut open coating ignited when exposed to the flame. [Table 1] [Table 2] [Table 3] [Table 4]

[0088] Formulation 1, which did not contain magnesium hydroxide or other flame retardants, ignited when the char directly above the flame-affected area was removed to the substrate. Formulation 2, in which approximately 67% of the APP was replaced with magnesium hydroxide, did not ignite after 5 minutes of flame exposure or after cutting the char and continuing the flame exposure.

[0089] While particular examples of the present disclosure have been described above for purposes of illustration, it will be apparent to those skilled in the art that many changes can be made in the details of the present disclosure without departing from the disclosure as defined in the appended claims.

Claims

1. 1. A flame retardant coating composition comprising: a) a film-forming component; b) a phosphate source; and c) TiO ２ and, d) a flame retardant; and e) a gas source; The film-forming component is present in an amount of 10 to 50 wt %, for example, 15 to 40 wt %, the phosphate source is present in an amount of 15 to 50 wt %, for example, 20 to 40 wt % or 15 to 35 wt %, and TiO ２ is present in an amount of 3 to 20 wt%, such as 3 to 8 wt% or 5 to 15 wt%, said flame retardant is present in an amount of 10 to 40 wt%, such as 15 to 30 wt%, and said gas source is present in an amount of 2 to 20 wt%, for example 2 to 5 wt%, wherein the wt% are based on the total solids weight of the composition.

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

3. 10. The coating composition of any one of the preceding claims, further comprising a borate source, a silica source, a zinc source, an acid source, a metal oxide, titanium isopropoxide, a carbon source, an inorganic filler, glass and / or mineral fibers, a rheological additive, an organic solvent, a pigment, a foam stabilizer, and combinations thereof.

4. 10. The coating composition of any one of the preceding claims, further comprising one or more additives in a total amount of 2 to 20 wt%, the weight percentages based on the total solids weight of the composition.

5. 10. The coating composition of any one of the preceding claims, wherein the film-forming components comprise an epoxy resin and an amine crosslinker, the phosphate source comprises ammonium phosphate, the flame retardant comprises a hydrated metal oxide, and the gas source comprises melamine, urea, and / or expandable graphite.

6. 10. The composition of any one of the preceding claims, wherein the composition is substantially free, essentially free, and / or completely free of one or more of the following: borate sources, alkyl phosphate(s), ethylenically unsaturated monomer residues such as those derived from melamine, (meth)acrylic and / or styrene, surfactants including but not limited to nonionic surfactants, silicates including but not limited to layered silicates and aluminum silicate(s), and piperazine salt(s).

7. A self-supporting film or sheet formed from a coating composition according to any one of the preceding claims.

8. 10. The coated or self-supporting film or sheet of any one of the preceding claims, wherein the coated film / sheet is flame retardant as determined according to a thermal runaway test.

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

10. The method of claim 9 , wherein the substrate comprises a metal, such as aluminum or steel, or a plastic, such as polycarbonate.

11. A substrate coated according to the method of claim 9 or 10.

12. An article comprising the substrate of claim 11.

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

14. 14. The article of claim 13, wherein the battery comprises exterior wall elements defining a housing, and optionally interior wall elements, and the coating composition or film or sheet is at least partially applied to the exterior and / or interior sides of any of the exterior wall elements and / or, if present, to any side of any of the interior wall elements.

15. The article of claim 14 , wherein any of the exterior and / or interior wall elements comprises a composite material, steel, aluminum, and / or polycarbonate.

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

17. The article of claim 16 , wherein the article comprises a vehicle.

18. 18. The vehicle of claim 17, wherein the vehicle has a surface at least partially coated with a fire-resistant ecoat, e.g., deposited from an electrodepositable composition comprising a flame-retardant pigment, an inorganic platelet-like pigment, e.g., a phyllosilicate pigment, and / or having a pigment-to-binder (P:B) ratio of at or above 0.4:1, e.g., at or above 0.5:1, up to 2.0:1, and / or formed from a composition comprising a flame-retardant adhesive, sealant, gap filler, potent, and / or encapsulant.

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. 9. A vehicle comprising a surface at least partially coated with the composition, sheet, or film of any one of claims 1 to 8, and an electric battery, wherein the composition, sheet, or film is between the surface and the battery.

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

23. 22. The vehicle of claim 21, further comprising a fire-resistant ecoat, e.g., deposited from an electrodepositable composition comprising a flame-retardant pigment, an inorganic plate-like pigment, e.g., a phyllosilicate pigment, and / or having a pigment-to-binder (P:B) ratio of 0.4:1 or greater, e.g., 0.5:1, up to 2.0:1, and / or a flame-retardant adhesive, sealant, gap filler, potent, and / or encapsulant, e.g., formed from a composition comprising a flame retardant.

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