Coating method of flame-retardant coating composition

Abstract

The present invention relates to a coating method for a flame-retardant coating composition, the method comprising: (a) applying a flame-retardant coating composition to a first surface of a support film (10) to generate a base film (11) having a flame-retardant coating layer (20) formed thereon; (b) applying a first porous adhesive layer (40) to a first surface (31) of a heat diffusion prevention layer (30); (c) laminating the base film (11) having the flame-retardant coating layer (20) formed thereon with the heat-diffusion-prevention layer (30) having the first porous adhesive layer (40) applied thereto such that the flame-retardant coating layer (20) comes into contact with the first porous adhesive layer (40), thereby forming a first laminate structure (50); (d) laminating the first laminated structure (50) so that the flame-retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40), wherein steps (a) and (b) are performed in any order, and the support film (10) does not contain a release agent.

Description

Coating method of flame retardant coating composition

[0001] The present invention relates to a method for coating a flame-retardant coating composition, and more particularly, to a method for coating a flame-retardant coating composition that exhibits excellent adhesion to the surface of various substrates including fiber materials.

[0002] Generally, flame-retardant coatings are compositions that delay ignition and prevent the spread of combustion in combustible materials and prevent deterioration in non-combustible materials in the event of a fire. Specifically, flame-retardant coatings protect combustible or non-combustible materials from heat or flames and are applied to the surfaces of various substrates, such as textiles. In particular, flame-retardant coatings must exhibit excellent adhesion to the substrate, even when particles are present on the substrate's surface.

[0003] Meanwhile, demand for large-capacity battery modules has been increasing recently. These battery modules are facing issues with thermal runaway damage.

[0004] To prevent thermal runaway in battery modules, thermal runaway prevention sheets are placed between cells within the module. Since most of these thermal runaway prevention sheets are made of fiber, a method for coating a flame-retardant coating composition with excellent flame retardancy and adhesion to fiber materials is needed.

[0005] [Prior Art Literature]

[0006] (Patent Document 1) Republic of Korea Publication No. 10-2023-0155545 (November 10, 2023)

[0007] One object of the present invention is to provide a method for coating a flame retardant coating composition having a variety of viscosities from high to low and excellent adhesion to a fiber material.

[0008] The present invention comprises the steps of: (a) applying a flame-retardant coating composition to a first surface of a support film (10) to create a base film (11) on which a flame-retardant coating layer (20) is formed; (b) applying a first porous adhesive layer (40) to a first surface (31) of a heat diffusion prevention layer (30); (c) laminating the base film (11) on which the flame-retardant coating layer (20) is formed and the heat diffusion prevention layer (30) on which the first porous adhesive layer (40) is applied so that the flame-retardant coating layer (20) and the first porous adhesive layer (40) are in contact with each other to form a first laminated structure (50); And (d) a step of laminating the first laminated structure (50) so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40); wherein steps (a) and (b) are performed in any order, and the support film (10) does not include a release agent. A method for coating a flame retardant coating composition is provided.

[0009] The coating method of the flame retardant coating composition according to the present invention can be used at various viscosities from high to low, so that it has excellent adhesion to a fiber material, allows for thin coating, has an excellent appearance, and is less affected by the physical properties of the material to be coated.

[0010] Figure 1 schematically illustrates a coating method of a flame retardant coating composition according to one embodiment of the present invention.

[0011] Figure 2 schematically illustrates a coating method of a flame retardant coating composition according to another embodiment of the present invention.

[0012] Hereinafter, various embodiments of the present invention will be described in detail.

[0013] The present invention provides a method for coating a flame retardant coating composition.

[0014] Figure 1 schematically illustrates a coating method of a flame retardant coating composition according to one embodiment of the present invention.

[0015] Referring to FIG. 1, a method for coating a flame-retardant coating composition according to the present invention comprises the steps of: (a) applying a flame-retardant coating composition to a first surface of a support film (10) to create a base film (11) on which a flame-retardant coating layer (20) is formed; (b) applying a first porous adhesive layer (40) to a first surface (31) of a heat diffusion prevention layer (30); (c) laminating the base film (11) on which the flame-retardant coating layer (20) is formed and the heat diffusion prevention layer (30) on which the first porous adhesive layer (40) is applied so that the flame-retardant coating layer (20) and the first porous adhesive layer (40) are in contact with each other to form a first laminated structure (50); and (d) laminating the first laminated structure (50) so that the flame-retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40). It includes steps. Here, steps (a) and (b) are performed in any order. Meanwhile, the support film (10) does not include a release agent.

[0016] Figure 2 schematically illustrates a coating method of a flame retardant coating composition according to another embodiment of the present invention.

[0017] Referring to FIG. 2, the coating method of the flame retardant coating composition according to the present invention comprises: (b') a step of applying a second porous adhesive layer (40') to the second surface (32) of the heat diffusion prevention layer (30) after step (b); (c') a step of forming a second laminated structure (50') by laminating the heat diffusion prevention layer (30) applied with another base film (11') so that the flame retardant coating layer (20) of another base film (11') on which the flame retardant coating layer (20) is formed and the second porous adhesive layer (40') are in contact with each other; and (d') a step of forming the second laminated structure (50') so that the flame retardant coating layer (20) on the another base film (11') and the heat diffusion prevention layer (30) are bonded by melting of the second porous adhesive layer (40'). Further comprising a laminating step, wherein steps (d) and (d') are performed in any order or simultaneously.

[0018] Each step is explained in detail below.

[0019] Step (a)

[0020] Step (a) is a step of creating a base film (11) on which a flame-retardant coating layer (20) is formed by applying a flame-retardant coating composition to the first surface of a support film (10).

[0021] FIG. 1(A) and FIG. 2(A) schematically show that a flame-retardant coating layer (20) is formed on the first surface of the support film (10).

[0022] The support film (10) may be, for example, a polyethylene terephthalate film (PET film) or a matte PET film, but is not limited thereto.

[0023] In step (a), a flame-retardant coating composition is coated on the first surface of a support film (10) using gravure, comma, slot die, etc., and processed to a desired thickness to form a flame-retardant coating layer (20).

[0024] Meanwhile, the support film (10) is characterized by not containing a release agent. If the support film (10) contains a release agent, a problem may arise in which the coating thickness of the flame-retardant coating composition is not formed uniformly due to shrinkage of the coating surface.

[0025] In one specific example, the flame retardant coating composition used in the present invention comprises 3 to 40 parts by weight of a water-soluble resin in solid content, 40 to 80 parts by weight of a flame retardant in solid content, 0.1 to 10 parts by weight of an additive in solid content, and 5 to 30 parts by weight of a solvent.

[0026] The flame-retardant coating composition of the present invention can be used at a variety of viscosities, from high to low, and exhibits excellent adhesion to textile materials, making it suitable for use in various coating methods. The flame-retardant coating composition may have a viscosity of 5,000 to 50,000 cPs at 25°C. Meanwhile, using the coating method of the flame-retardant coating composition of the present invention, the flame-retardant coating composition can be coated to a thickness of at least 30 μm.

[0027] The water-soluble resin is a main resin that forms a coating film formed by the flame-retardant coating composition of the present invention. The flame-retardant coating composition of the present invention includes a water-dispersible resin to ensure excellent flame-retardant performance.

[0028] The water-soluble resin of the present invention includes at least one selected from the group consisting of ethylene vinylacetate (EVA) resin, polyvinylchloride resin, water-soluble acrylic resin, polyvinylacetate (PVAC) resin, polybutadiene resin, polyvinylidene chloride resin, and polyurethane (PU) resin.

[0029] When ethylene vinyl acetate resin is used as a water-soluble resin, it is effective because it has strong cohesiveness and can maintain the strength of the flame-retardant coating layer formed by the flame-retardant coating composition of the present invention at a certain level or higher.

[0030] The ethylene vinyl acetate resin of the present invention has a solid content of 98 wt% or more based on the total weight of the resin and a density of 400 to 550 kg / m. 3 , the particle size is 400 ㎛ or more, and the content of such particles is up to 4 wt%.

[0031] The water-soluble resin is included in the flame-retardant coating composition in an amount of 3 to 40 parts by weight, 5 to 35 parts by weight, or 10 to 30 parts by weight based on the solid content. If the amount of the water-soluble resin is less than 3 parts by weight, a coating film may not be formed, and if it exceeds 40 parts by weight, a problem of reduced flame retardancy may occur.

[0032] Meanwhile, the flame-retardant coating composition of the present invention further comprises a thermoplastic resin. The thermoplastic resin serves to impart flexibility to the coating film.

[0033] The thermoplastic resin of the present invention includes at least one selected from the group consisting of polyvinyl alcohol, polyvinyl formal, polyvinyl butyral (PVB), polyethylene terephthalate, polycaprolactam, polyhexamethylene adipamide, polycarbonate, polycarbonate / ABS resin, polyacetal, polyphenylene sulfatadiene, polyurethane, and cellulose-based resins, and is preferably a polyvinyl butyral (PVB) resin, but is not limited thereto.

[0034] The thermoplastic resin is included in the flame retardant coating composition in an amount of from 0 to 20 parts by weight or from 5 to 15 parts by weight based on the solid content.

[0035] Flame retardants serve to impart flame retardant properties to the coating.

[0036] The flame retardant of the present invention includes a non-halogen flame retardant instead of a halogen flame retardant. In the case of a halogen flame retardant, when a fire occurs, a large amount of smoke and toxicity are generated and corrosive hydrogen halide gas is generated, which not only causes environmental problems but also reduces mechanical properties.

[0037] Therefore, in order to solve these problems, the present invention uses a non-halogen flame retardant, and in one specific example, the flame retardant of the present invention includes a phosphorus-based flame retardant and a metal hydroxide-based flame retardant.

[0038] The phosphorus-based flame retardant of the present invention imparts excellent flame retardancy to coatings in a solid-state reaction. Specifically, the phosphorus-based flame retardant of the present invention is a polymer that forms carbonaceous ash (char) upon thermal decomposition. This ash formation reduces combustible fuel and forms a thick barrier on the surface of combustible molecules, blocking heat and thus extinguishing fire.

[0039] This action occurs in the condensed phase, and phosphorus is an important condensed phase flame retardant. Phosphorus decomposes thermally to form phosphoric acid, which acts as a dehydration catalyst in combustible materials, increasing the amount of char. Notably, phosphorus (P)-based flame retardants are environmentally friendly materials that do not produce dioxins, a carcinogen.

[0040] In one specific example, the phosphorus flame retardant of the present invention comprises at least one selected from the group consisting of ammonium polyphosphate (APP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), triethyl phosphate (TEP), isopropyl phenyl diphenyl phosphate, red phosphorus (CG-P), tris(2-chloroethyl)phosphate (TCEP), and resorcinol di phosphate (RDP).

[0041] The metal hydroxide-based flame retardant of the present invention does not volatilize under heat, but decomposes to release non-flammable gases such as water, carbon dioxide, sulfur dioxide, and hydrogen chloride, and produces water through thermal decomposition, thereby imparting a flame retardant effect to the coating. Furthermore, it prevents combustion through a cooling effect caused by heat absorption and the generated water.

[0042] In one specific example, the metal hydroxide-based flame retardant of the present invention includes at least one selected from the group consisting of aluminum hydroxide (Al(OH)3), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2).

[0043] Metal hydroxide flame retardants may be included for synergistic effects with phosphorus-based flame retardants. Zinc borate and aluminum hydroxide may be effective in suppressing smoke.

[0044] The flame retardant is included in the flame retardant coating composition in an amount of 40 to 80 parts by weight, 45 to 70 parts by weight, or 47 to 60 parts by weight based on the solid content. If the flame retardant content is less than 40 parts by weight, the coating film may burn upon initial ignition, and if it exceeds 80 parts by weight, the excessive amount included makes it difficult to form the coating film.

[0045] Meanwhile, the flame retardant comprises a solid content of 0.1 to 25 parts by weight or 1 to 20 parts by weight of a phosphorus-based flame retardant, and a solid content of 20 to 45 parts by weight or 25 to 40 parts by weight of a metal hydroxide-based flame retardant.

[0046] If the content of the phosphorus flame retardant is below the above range, the effect of providing flexibility to the sheet for preventing thermal runaway due to the phosphorus flame retardant is insufficient, and if it exceeds the above range, problems may occur in the appearance of the manufactured coating film.

[0047] While higher metal hydroxide flame retardant content significantly improves flame retardant properties, it can also release toxic gases, potentially posing a risk to human health. Therefore, metal hydroxide flame retardants are included in the minimum amount necessary to ensure non-combustibility.

[0048] In one specific example, the weight ratio of the phosphorus-based flame retardant and the metal hydroxide-based flame retardant is 1:1 to 1:30, or 1:2 to 1:25, based on solid content.

[0049] When the weight ratio of the phosphorus-based flame retardant and the metal hydroxide-based flame retardant is less than 1:1, the surface temperature of the coating film rises rapidly, making it difficult to delay ignition. On the other hand, when the weight ratio of the phosphorus-based flame retardant and the metal hydroxide-based flame retardant exceeds 1:30, it is difficult to disperse them within the flame-retardant coating composition, which hinders the uniformity of the coating film, and the bendability is poor, and the coating film drying time is fast, making it difficult to work in the coating process.

[0050] In one specific example, in the flame retardant coating composition of the present invention, the ratio (A:B) of the sum (A) of the weight of the water-soluble resin and the weight of the thermoplastic resin and the weight (B) of the flame retardant is 1:1 to 1:10 or 1:2 to 1:8 based on the solid content.

[0051] If the ratio (A:B) of the sum of the weight of the water-soluble resin and the weight of the thermoplastic resin (A) and the weight of the flame retardant (B) is less than 1:1, it takes a long time for the coating film to ignite and completely burn out, and there is a problem that the flame retardancy and non-combustibility characteristics are reduced. On the other hand, if the weight ratio (A:B) exceeds 1:10, the flame retardant ratio is high, making dispersion difficult and the uniformity of the coating film is deteriorated.

[0052] In one specific example, in the flame retardant coating composition of the present invention, the flame retardant further comprises 20 to 40 parts by weight or 25 to 35 parts by weight of the solid content of the filler.

[0053] In the present invention, the filler may be, for example, calcium carbonate, mica, kaolin, talc, etc., but is not limited thereto.

[0054] The additive includes at least one selected from an aqueous dispersant and a pigment.

[0055] The additive is included in the flame retardant coating composition in an amount of 0.1 to 10 parts by weight based on the solid content.

[0056] The aqueous dispersant plays a role in improving the dispersibility of the flame retardant. The aqueous dispersant of the present invention may be non-silicone-based, and may be, for example, product names BYK-011, 012, 014, 015, 021, 022, 024, 037, 054T, 092, 093, 190, 40, 10, 326, 346, 347, 348, 349.

[0057] The water-based dispersant is included in the flame-retardant coating composition in an amount of 1 to 10 parts by weight based on the solid content.

[0058] Pigments play a role in imparting color to the coating. In the present invention, the pigments may be, for example, product names RAVEN 1200, MA100, MA600MJS, NEROX 1000, RAVEN1170, PRINTEX 200, DENKA BLACK, RAVEN 14, BLACK PEARL 1400, and RAVEN R900.

[0059] The pigment is included in the flame retardant coating composition in an amount of 0.1 to 5 parts by weight based on the solid content.

[0060] The solvent serves to control the viscosity of the flame retardant coating composition.

[0061] In the present invention, the solvent includes water. The solvent is preferably water such as deionized water or distilled water.

[0062] The solvent is included in the flame retardant coating composition in an amount of 5 to 30 parts by weight or 10 to 20 parts by weight.

[0063] Step (b)

[0064] Step (b) is a step of applying a first porous adhesive layer (40) to the first surface (31) of the heat diffusion prevention layer (30).

[0065] Figures 1(B) and 2(B1) schematically show that a first porous adhesive layer (40) is applied to the first surface (31) of a heat diffusion prevention layer (30).

[0066] In one specific example, the thermal diffusion prevention layer (30) is manufactured by impregnating a fiber-reinforced core material with an impregnating solution containing silica. The thermal diffusion prevention layer (30) has a cushioning function, assisting in the swelling phenomenon of the battery cell, and acts as an insulating layer to delay heat transfer in the event of thermal runaway.

[0067] The fiber-reinforced core material comprises at least one fiber selected from polyester, polyacrylonitrile (PAN), oxidized polyacrylonitrile, non-carbonized heat-treated PAN, carbon, silica, polyaramid, polycarbonate, polyolefin, rayon, nylon, glass wool, high-density polyolefin, ceramic, acrylic, fluoropolymer, polyurethane, polyamide, and polyimide.

[0068] In one specific example, the fiber-reinforced core contains 30 to 100 wt% of oxidized polyacrylonitrile fiber (OPF) based on the total weight of the fiber-reinforced core, wherein the fiber-reinforced core has voids therein.

[0069] Meanwhile, the fiber-reinforced core material may be a porous nonwoven fabric containing, for example, oxidized polyacrylonitrile fibers (OPF) and having pores within the fabric. Here, OPF is a fiber containing oxidized polyacrylonitrile (Oxi-PAN), and is one type of porous inorganic fiber core material.

[0070] The fiber-reinforced core may have a thermal conductivity of, for example, 0.1 W / m K or less. If the thermal conductivity of the fiber-reinforced core exceeds 0.1 W / m K, the heat of a thermal runaway cell may be transferred to adjacent cells within tens of seconds, rapidly reaching the temperature at which thermal runaway occurs, making it difficult to secure sufficient time for a person to escape from the vehicle.

[0071] The fiber-reinforced core may also have a thickness of 10 mm or less, or 6 mm or less, or 0.1 to 4 mm. If the fiber-reinforced core is less than 0.1 mm thick, it may be difficult to sufficiently provide insulation. If the thickness exceeds 10 mm, the insulation effect is excellent, but the battery capacity is reduced due to insufficient internal space, which limits its practical application.

[0072] Meanwhile, the fiber-reinforced core material has a density of 80 to 250 kg / ㎥, or 85 to 230 kg / ㎥. When the fiber-reinforced core material satisfies the above density range, the impregnating solution described below and the particles contained therein can be appropriately distributed on the surface of the fiber-reinforced core material to fill the pores.

[0073] In one specific example, the impregnating liquid of the present invention comprises a solvent and silica.

[0074] Silica is distributed and attached to the surface of the fiber-reinforced core yarn, filling the pores. In the present invention, the fiber-reinforced core is impregnated with a silica-containing impregnation solution, so that the silica fills the pores of the fiber-reinforced core to a predetermined level. This allows the thermal conductivity of the fiber-reinforced core to be adjusted to a predetermined level, thereby achieving a desirable heat transfer delay effect.

[0075] The impregnating solution contains 100 parts by weight of solvent and 3 to 20 parts by weight of silica.

[0076] The solvent is water, preferably distilled water or deionized water. The solvent is included in the impregnating liquid in an amount of 100 parts by weight.

[0077] Silica is an inorganic silica. Inorganic silica includes, for example, fumed silica, precipitated silica, silica glass, or silicon ester.

[0078] Fumed silica is manufactured by hydrolyzing tetrachlorosilane in a flame at a high temperature of over 1000℃. The powder density is low at around 0.05g / mL and the silica purity is very high. Fumed silica has a large space between particles, which minimizes heat transfer by gases, and its low thermal conductivity also reduces heat transfer by itself. In addition, fumed silica is stable at high temperatures and is flame retardant, so it has excellent heat retardation effect.

[0079] Silica is included in the impregnating solution in an amount of 3 to 20 parts by weight, or 5 to 15 parts by weight, based on 100 parts by weight of the solvent. If the silica content exceeds the above range, the heat retardation effect may be reduced.

[0080] Meanwhile, the impregnating solution may further include at least one of a silane compound, an organic resin, and a silica sol. Specifically, based on 100 parts by weight of the solvent, the impregnating solution may include 0.1 to 10 parts by weight of the silane compound, 0.01 to 10 parts by weight of the organic resin, or more than 0 to 15 parts by weight of the silica sol.

[0081] The silane compound reacts with the hydroxyl group of the fiber-reinforced core to further bind the fiber-reinforced core and attaches silica to the surface of the fiber-reinforced core yarn.

[0082] The silane compound may include a difunctional or more, trifunctional or tetrafunctional alkoxy silane, or a silicone resin in which the number of oxygen atoms bonded to each silicon atom is 1 to 4.

[0083] Silane compounds have the chemical formula (R a SiO 3 / 2 ) a (R b 2SiO 2 / 2 ) b (R c 3SiO 1 / 2 ) c It may include a branched chain organopolysiloxane having an average unit of R. Here, R a , R b , and R c are each the same or different and substituted or unsubstituted monovalent hydrocarbon groups, a is a positive number, b is 0 or a positive number, and c is 0 or a positive number.

[0084] Specifically, the silane compounds are tetramethoxy silane, tetraethoxy silane, tetra-n-propoxy silane, tetraisopropoxy silane, tetra-n-butoxy silane, tetraisobutoxy silane, methyltrimethoxy silane, methyltriethoxy silane, ethyltrimethoxy silane, isobutyltrimethoxy silane, vinyltrimethoxy silane, vinyltriethoxy silane, γ-methacryloxypropyltrimethoxy silane, γ-methacryloxypropyltriethoxy silane, γ-acryloxypropyltrimethoxy silane, γ-acryloxypropyltriethoxy silane, β-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, γ-glycidoxypropyltrimethoxy silane, γ-aminopropyltrimethoxy silane, It may be at least one selected from the group consisting of N-β-(aminoethyl)-γ-aminopropyltriethoxy silane, dimethyldimethoxy silane, vinylmethyldimethoxy silane, γ-methacryloxypropylmethyldimethoxy silane, γ-acryloxypropylmethyldimethoxy silane, γ-glycidoxypropylmethyldimethoxy silane, γ-glycidoxypropylmethyldiethoxy silane, γ-aminopropylmethyldimethoxy silane, γ-isocyanatopropyltrimethoxy silane, γ-isocyanatopropyltriethoxy silane, phenyltriethoxy silane, and phenyltrimethoxy silane.

[0085] The silane compound is included in the impregnating solution in an amount of 0.1 to 15 parts by weight, or 0.1 to 10 parts by weight. If the amount of the silane compound is less than the above range, it is difficult to secure physical properties such as strength and water resistance of the manufactured product. If the amount exceeds the above range, the stability of the impregnating solution may be reduced and the strength of the manufactured product may be reduced.

[0086] The organic resin acts as an elastic resin to prevent battery cell swelling. The organic resin may include, for example, an acrylic resin.

[0087] The organic resin is included in the impregnating solution in an amount of 0.1 to 10 parts by weight, or 0.1 to 5 parts by weight, based on 100 parts by weight of the solvent. If the amount of the organic resin is less than the above range, the elastic effect may be reduced, and if it exceeds the above range, the heat retardation effect may be reduced.

[0088] Silica sol, together with a silane compound, further binds the fiber-reinforced core and attaches silica to the surface of the fiber-reinforced core yarn. Silica sol is included in the impregnation solution in an amount of more than 0 to 15 parts by weight, or 0.1 to 10 parts by weight. If the silica sol content exceeds the above range, the strength of the manufactured product may be reduced.

[0089] In one specific example, the first porous adhesive layer (40) is in the form of a web having a plurality of pores in which fibers made of a hot melt material are accumulated, and the hot melt is a type of liquid adhesive that exhibits adhesive properties when heat is applied, and it is preferable that the hot melt web adhesive layer be in the form of a solid sheet.

[0090] The first porous adhesive layer (40) is a hot melt web adhesive layer made of a material including at least one selected from the group consisting of polyamide, polyester, polyurethane, polyolefin, and ethylene vinyl acetate (EVA).

[0091] The first porous adhesive layer (40) preferably has a glass transition temperature of 60 to 150°C and a melt index of 30 to 200 cm3 / 10 min. If the melt index is less than 30 cm3 / 10 min, the adhesive strength of the hot melt adhesive layer is reduced, and if it exceeds 200 cm3 / 10 min, the molten hot melt web adhesive layer flows into the pores and fills the pores, thereby reducing the flame retardancy of the hot melt adhesive layer.

[0092] Step (c)

[0093] Step (c) is a step of forming a first laminated structure (50) by laminating a base film (11) on which a flame-retardant coating layer (20) is formed and a heat diffusion prevention layer (30) on which a first porous adhesive layer (40) is applied so that the flame-retardant coating layer (20) and the first porous adhesive layer (40) are in contact.

[0094] A first laminated structure (50) is schematically shown in which a base film (11) having a flame-retardant coating layer (20) formed on Fig. 1(C) and Fig. 2(C1) and a heat diffusion prevention layer (30) having a first porous adhesive layer (40) applied thereto are laminated.

[0095] In order to allow the flame retardant coating layer (20) and the heat diffusion prevention layer (30) to be bonded by the first porous adhesive layer (40), a first laminated structure (50) is formed so that the first porous adhesive layer (40) is positioned between the flame retardant coating layer (20) and the heat diffusion prevention layer (30).

[0096] Step (d)

[0097] Step (d) is a step of laminating the first laminated structure (50) so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40).

[0098] In one specific example, the laminating step is performed at a temperature of 80 to 170°C and a pressure of 3 to 5 kgf / cm 2 Lamination is performed by pressurizing with a pressure of 3 to 5 kgf / cm at a temperature of 80 to 170 ℃. 2 It is pressed and laminated under pressure.

[0099] The temperature for laminating the first laminated structure (50) can be set according to the glass transition temperature (Tg) of the first porous adhesive layer (40). In the present invention, the temperature for laminating the first laminated structure (50) can be, for example, 80 to 120°C or 130 to 170°C.

[0100] Meanwhile, the pressing pressure for laminating the first laminated structure (50) is 3 to 5 kgf / cm 2 am.

[0101] The first porous adhesive layer (40) is melted and pressurized to adhere the flame retardant coating layer (20) to the heat diffusion prevention layer (30).

[0102] The flame retardant coating layer (20) adhered to the heat diffusion prevention layer (30) effectively blocks dust generated from the heat diffusion prevention layer (30), protects the heat diffusion prevention layer (30) from external flames when a battery thermal runaway occurs, and also contributes to some delay in heat transfer.

[0103] The present invention can adhere a flame retardant coating layer (20) to a first surface (31) of a heat diffusion prevention layer (30) by melting a first porous adhesive layer (40) through steps (a) to (d).

[0104] Meanwhile, after laminating in step (d), the support film (10) can be released from the flame-retardant coating layer (20) by lowering the temperature to room temperature. Accordingly, the support film (10) can be removed from the laminated structure (50) if necessary.

[0105] In one specific example, the present invention further comprises steps (b') and (c') as follows, whereby another flame retardant coating layer (20) can be additionally bonded to the second surface (32) of the heat diffusion prevention layer (30) by melting the second porous adhesive layer (40').

[0106] Step (b')

[0107] Step (b') is a step of applying a second porous adhesive layer (40') to the second surface (32) of the thermal diffusion prevention layer (30) after step (b). Step (b') is the same as step (b), and the only difference is that the second porous adhesive layer (40') is applied again to the second surface (32) of the thermal diffusion prevention layer (30) on which the first porous adhesive layer (40) is applied to the first surface (31).

[0108] Therefore, the second porous adhesive layer (40') is the same as the first porous adhesive layer (40), but the material thereof may be the same or different.

[0109] In Fig. 2(B2), a second porous adhesive layer (40') is schematically shown applied to the second surface (32) of a heat diffusion prevention layer (30) on which a first porous adhesive layer (40) is applied to the first surface (31).

[0110] Step (c')

[0111] Step (c') is a step of forming a second laminated structure (50') by laminating another base film (11') and a heat diffusion prevention layer (30) to which the second porous adhesive layer (40') is applied so that the flame-retardant coating layer (20) of another base film (11') on which the flame-retardant coating layer (20) is formed and the second porous adhesive layer (40') are in contact after step (c).

[0112] A second laminated structure (50') is schematically shown in which another base film (11') having a flame-retardant coating layer (20) formed on Fig. 2 (C2) and a heat diffusion prevention layer (30) coated with a second porous adhesive layer (40') are laminated.

[0113] Step (d')

[0114] When the present invention includes steps (b') and (c'), a step (d') of laminating the second laminated structure (50') is included so that the flame retardant coating layer (20) on the other base film (11') and the heat diffusion prevention layer (30) are bonded by melting of the second porous adhesive layer (40').

[0115] Step (d') can be performed under the same conditions as step (d). For example, step (d') can be performed under the same conditions as step (d). For example, step (d') can be performed under the same conditions as step (d). 2 It is performed at a pressure of 3 to 5 kgf / cm at a temperature of 80 to 170 ℃. 2 It is pressed and laminated under pressure.

[0116] Here, the laminating steps, i.e., steps (d) and (d'), may be performed in any order or simultaneously.

[0117] Meanwhile, the flame retardant coating composition of the present invention can be adhered to the heat diffusion prevention layer (30) by a direct coating method using a roller, a coating method using a brush, or a spray coating method.

[0118] Direct coating using a roller is a method of directly coating the area of ​​the substrate that requires coating or finishing.

[0119] After diluting the flame-retardant coating composition to the desired viscosity, apply it to the target object by passing it between the rolls of the equipment. After application, dry it at 80-100°C.

[0120] The flame retardant coating composition of the present invention can be diluted to a desired viscosity with ultrapure water and is easy to clean.

[0121] Coating equipment includes roll-to-roll, direct gravure, micro gravure, comma direct, and slot die. Direct coating allows for flame-retardant coating compositions with viscosities ranging from 300 to 100,000 mPas, with coating thicknesses ranging from 30 to 2,000 ㎛. If reapplication is possible after coating, a second coat offers the advantage of a superior appearance compared to a single coat.

[0122] Brush or spray coating methods are convenient for applying a thin layer of flame retardant coating composition.

[0123] Hereinafter, various embodiments of the present invention will be described.

[0124] [Specific Example 1] (a) a step of applying a flame-retardant coating composition to a first surface of a support film (10) to create a base film (11) having a flame-retardant coating layer (20) formed thereon; (b) a step of applying a first porous adhesive layer (40) to a first surface (31) of a heat diffusion prevention layer (30); (c) a step of laminating the base film (11) having the flame-retardant coating layer (20) formed thereon and the heat diffusion prevention layer (30) having the first porous adhesive layer (40) applied thereon so that the flame-retardant coating layer (20) and the first porous adhesive layer (40) are in contact with each other to form a first laminated structure (50); And (d) a step of laminating the first laminated structure (50) so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40); wherein steps (a) and (b) are performed in any order, and the support film (10) does not include a release agent. A method for coating a flame retardant coating composition.

[0125] [Specific Example 2] In Specific Example 1, after step (b), a step of applying a second porous adhesive layer (40') to the second surface (32) of the heat diffusion prevention layer (30); (c') after step (c), a step of forming a second laminated structure (50') by laminating the heat diffusion prevention layer (30) to which the second porous adhesive layer (40') is applied and the flame retardant coating layer (20) of another base film (11') on which the flame retardant coating layer (20) is formed so that the second porous adhesive layer (40') is in contact with the flame retardant coating layer (20) of another base film (11'); And (d') a step of laminating the second laminated structure (50') so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) on the other base film (11') are bonded by melting of the second porous adhesive layer (40'); A method for coating a flame retardant coating composition, wherein steps (d) and (d') are performed in any order or simultaneously.

[0126] [Specific Example 3] In Specific Example 1 or Specific Example 2, the laminating step is performed at a temperature of 80 to 170°C and a pressure of 3 to 5 kgf / cm 2 A method for coating a flame retardant coating composition, wherein lamination is performed by pressurizing with pressure.

[0127] [Specific Example 4] In Specific Example 1, the flame-retardant coating composition comprises 3 to 40 parts by weight of a water-soluble resin in solid content, 40 to 80 parts by weight of a flame retardant in solid content, 0.1 to 10 parts by weight of an additive in solid content, and 5 to 30 parts by weight of a solvent, and the heat diffusion prevention layer (30) is a coating method of a flame-retardant coating composition manufactured by impregnating a fiber-reinforced core material in an impregnation liquid containing silica.

[0128] [Specific Example 5] In Specific Example 4, the water-soluble resin includes at least one selected from the group consisting of ethylene vinylacetate (EVA) resin, polyvinylchloride resin, water-soluble acrylic resin, polyvinylacetate (PVAC) resin, polybutadiene resin, polyvinylidene chloride resin, and polyurethane (PU) resin, the flame retardant includes a phosphorus-based flame retardant and a metal hydroxide-based flame retardant, and the fiber-reinforced core material is a fiber of the fiber-reinforced core material selected from the group consisting of polyester, polyacrylonitrile (PAN), oxidized polyacrylonitrile, non-carbonized heat-treated PAN, carbon, silica, polyaramid, polycarbonate, polyolefin, rayon, nylon, glass wool, high-density polyolefin, ceramic, acrylic, fluoropolymer, polyurethane, A method for coating a flame-retardant coating composition comprising at least one selected from polyamide and polyimide, wherein the impregnating liquid comprises a solvent and silica.

[0129] [Specific Example 6] In Specific Example 5, the phosphorus-based flame retardant includes at least one selected from the group consisting of ammonium polyphosphate (APP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), triethyl phosphate (TEP), isopropyl phenyl diphenyl phosphate, red phosphorus (CG-P), tris(2-chloroethyl)phosphate (TCEP), and resorcinol di phosphate (RDP), and the metal hydroxide-based flame retardant includes at least one selected from the group consisting of aluminum hydroxide (Al(OH)3), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2). A coating method of a coating composition.

[0130] [Specific Example 7] In Specific Example 5, the fiber-reinforced core material contains 30 to 100 wt% of oxidized polyacrylonitrile fiber (OPF) based on the total weight of the fiber-reinforced core material and has pores inside, and the silica includes at least one selected from fumed silica, precipitated silica, silica glass, and silicon ester, a coating method for a flame-retardant coating composition.

[0131] [Specific Example 8] In Specific Example 1, the first porous adhesive layer (40) is a hot melt web adhesive layer made of a material including at least one selected from the group consisting of polyamide, polyester, polyurethane, polyolefin, and ethylene vinyl acetate (EVA). A method for coating a flame retardant coating composition.

Claims

1. (a) A step of applying a flame-retardant coating composition to the first surface of a support film (10) to create a base film (11) on which a flame-retardant coating layer (20) is formed; (b) a step of applying a first porous adhesive layer (40) to the first surface (31) of the heat diffusion prevention layer (30); (c) a step of forming a first laminated structure (50) by laminating the base film (11) on which the flame-retardant coating layer (20) is formed and the heat diffusion prevention layer (30) on which the first porous adhesive layer (40) is applied so that the flame-retardant coating layer (20) and the first porous adhesive layer (40) are in contact with each other; and (d) a step of laminating the first laminated structure (50) so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) are bonded by melting of the first porous adhesive layer (40); Includes, Steps (a) and (b) are performed in any order, A method for coating a flame retardant coating composition, wherein the above support film (10) does not contain a release agent.

2. In claim 1, (b') After step (b), a step of applying a second porous adhesive layer (40') to the second surface (32) of the heat diffusion prevention layer (30); (c') After step (c), a step of forming a second laminated structure (50') by laminating another base film (11') and the heat diffusion prevention layer (30) to which the second porous adhesive layer (40') is applied so that the flame retardant coating layer (20) of another base film (11') on which the flame retardant coating layer (20) is formed and the second porous adhesive layer (40') are in contact with each other; and (d') A step of laminating the second laminated structure (50') so that the flame retardant coating layer (20) and the heat diffusion prevention layer (30) on the other base film (11') are bonded by melting of the second porous adhesive layer (40'); , and further includes: A method for coating a flame retardant coating composition, wherein steps (d) and (d') are performed in any order or simultaneously.

3. In claim 1 or claim 2, The above laminating step is performed at a temperature of 80 to 170 ℃ and a pressure of 3 to 5 kgf / cm 2 A method for coating a flame retardant coating composition, wherein lamination is performed by pressurizing with pressure.

4. In claim 1, The flame retardant coating composition comprises 3 to 40 parts by weight of a water-soluble resin in solid content, 40 to 80 parts by weight of a flame retardant in solid content, 0.1 to 10 parts by weight of an additive in solid content, and 5 to 30 parts by weight of a solvent. The above heat diffusion prevention layer (30) is a coating method of a flame retardant coating composition manufactured by impregnating a fiber-reinforced core material with an impregnation liquid containing silica.

5. In claim 4, The water-soluble resin includes at least one selected from the group consisting of ethylene vinylacetate (EVA) resin, polyvinylchloride resin, water-soluble acrylic resin, polyvinylacetate (PVAC) resin, polybutadiene resin, polyvinylidene chloride resin, and polyurethane (PU) resin. The above flame retardants include phosphorus-based flame retardants and metal hydroxide-based flame retardants, The above fiber-reinforced core material comprises at least one selected from the group consisting of polyester, polyacrylonitrile (PAN), oxidized polyacrylonitrile, non-carbonized heat-treated PAN, carbon, silica, polyaramid, polycarbonate, polyolefin, rayon, nylon, glass wool, high-density polyolefin, ceramic, acrylic, fluoropolymer, polyurethane, polyamide, and polyimide. A method for coating a flame retardant coating composition, wherein the impregnating liquid comprises a solvent and silica.

6. In claim 5, The above-mentioned phosphorus flame retardant comprises at least one selected from the group consisting of ammonium polyphosphate (APP), triphenyl phosphate (TPP), tricresyl phosphate (TCP), triethyl phosphate (TEP), isopropyl phenyl diphenyl phosphate, red phosphorus (CG-P), tris(2-chloroethyl)phosphate (TCEP), and resorcinol di phosphate (RDP). A method for coating a flame-retardant coating composition, wherein the metal hydroxide-based flame retardant comprises at least one selected from the group consisting of aluminum hydroxide (Al(OH)3), calcium hydroxide (Ca(OH)2), and magnesium hydroxide (Mg(OH)2).

7. In claim 5, The above fiber-reinforced core material contains 30 to 100 wt% of oxidized polyacrylonitrile fiber (OPF) based on the total weight of the fiber-reinforced core material and has voids inside. A method for coating a flame-retardant coating composition, wherein the silica comprises at least one selected from fumed silica, precipitated silica, silica glass, and silicon ester.

8. In claim 1, A method for coating a flame retardant coating composition, wherein the first porous adhesive layer (40) is a hot melt web adhesive layer made of a material including at least one selected from the group consisting of polyamide, polyester, polyurethane, polyolefin, and ethylene vinyl acetate (EVA).

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