Polyacrylic acid-based fireproof coating and preparation method thereof, silicone composite polyacrylic acid fireproof material and preparation method thereof

Abstract

This invention relates to the field of composite material technology, and discloses a polyacrylic acid-based fire-retardant coating and its preparation method, and an organosilicon composite polyacrylic acid flame-retardant material and its preparation method. The method includes: mixing and reacting an acrylate phosphate monomer with a phosphorus-boron flame retardant and an inorganic filler in the presence of an initiator to obtain the polyacrylic acid-based fire-retardant coating; wherein the phosphorus-boron flame retardant is a combination of a phosphorus-containing flame retardant and a boron-containing flame retardant in a weight ratio of 1:0.5-1.5; and the weight ratio of the acrylate phosphate monomer, the phosphorus-boron flame retardant, and the inorganic filler is 1:0.05-0.3:0.2-0.6. The organosilicon composite polyacrylic acid flame-retardant material prepared by the technical solution provided by this invention has excellent fire-retardant and heat-insulating properties, and significantly improves the flame-retardant performance, smoke suppression and toxicity reduction performance, and high-temperature resistance of PDMS foam, and can be applied in the fields of flame-retardant heat insulation and thermal protection of energy storage batteries.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to polyacrylic acid-based fire-retardant coatings and their preparation methods, and organosilicon composite polyacrylic acid flame-retardant materials and their preparation methods. Background Technology

[0002] In the field of nanoporous materials, polydimethylsiloxane (PDMS) foam has become an important candidate to replace traditional aerogel materials due to its unique molecular structure and physicochemical properties. Compared with porous materials such as aerogels, PDMS foam has significant advantages in mechanical toughness, environmental adaptability, processing technology, and functional integration, and its specific molecular chain structure gives it excellent chemical stability. However, because its open / closed-cell structure forms heat conduction channels and combustible gas diffusion paths, the pyrolysis of PDMS at high temperatures, combined with the synergistic effect of its pore structure, leads to rapid heat transfer and rapid flame spread, making it difficult to meet the flame-retardant requirements of fire fighting and high-temperature operations.

[0003] Surface ceramic coating technology constructs a precursor coating on the material surface through a curing process, which then forms a ceramic layer through high-temperature pyrolysis. This protects the matrix from thermal degradation. Furthermore, the ceramic layer, due to its high stability, low thermal conductivity, and dense properties, inhibits the transfer of heat and combustible gases, thus suppressing fire spread without damaging the material's original mechanical properties. This technology is considered an environmentally friendly and promising strategy for endowing materials with high performance. Fire-retardant coatings can effectively protect the matrix and can be flexibly applied to high-temperature insulation products. Conventionally, increasing the proportion of internal inorganic fillers can enhance the fire resistance and heat resistance of materials. However, the hydrophobic surface of PDMS foam results in insufficient adhesion between the filler and the coating, leading to easy separation and limiting its application.

[0004] CN102532505A discloses a method for preparing polycarbonate-polydimethylsiloxane nanocomposites. The method includes: adding polydimethylsiloxane, diphenyl carbonate, and magnesium chloride to a reaction vessel; under inert gas protection; sequentially stirring and heating to carry out a molten transesterification reaction; cooling the product after the reaction; then adding bisphenol A; under inert gas protection; stirring and heating to carry out a polycondensation reaction; adding nanomaterials during the polycondensation reaction to obtain the final product; then adding the product to dichloromethane; washing with anhydrous ethanol; filtering; and drying the filter cake to obtain the polycarbonate-polydimethylsiloxane nanocomposites. This composite is an environmentally friendly flame-retardant polycarbonate that can reduce the maximum heat release rate of polycarbonate. However, this preparation method yields flame-retardant materials with poor consistency and unstable actual flame-retardant effects. Furthermore, the preparation process is relatively complex, and the use of the toxic solvent dichloromethane is environmentally unfriendly. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing polydimethylsiloxane foams, such as insufficient interfacial adhesion between the foam and the ceramic coating, insufficient resistance to high-pressure gas breakdown, and insufficient fire resistance.

[0006] To achieve the above objectives, a first aspect of the present invention provides a method for preparing a polyacrylic acid-based fire-retardant coating, the method comprising: In the presence of an initiator, acrylate phosphate monomers are mixed and reacted with phosphorus boron flame retardants and inorganic fillers to obtain the polyacrylic acid-based fire-retardant coating. The phosphorus-boron flame retardant is a combination of a phosphorus-containing flame retardant and a boron-containing flame retardant in a weight ratio of 1:0.5-1.5. The weight ratio of the acrylate phosphate monomer, the phosphorus boron flame retardant, and the inorganic filler is 1:0.05-0.3:0.2-0.6.

[0007] A second aspect of the present invention provides a polyacrylic acid-based fire-retardant coating prepared by the method described in the first aspect.

[0008] A third aspect of the present invention provides an organosilicon composite polyacrylic acid flame retardant material, the organosilicon composite polyacrylic acid flame retardant material comprising a modified organosilicon foam layer and a polyacrylic acid-based fire-retardant coating applied to the upper and lower surfaces of the modified organosilicon foam layer; The polyacrylic fire-retardant coating is formed from the polyacrylic fire-retardant coating described in the second aspect; The modified organosilicon foam layer is obtained by modifying the organosilicon foam layer with silica sol.

[0009] A fourth aspect of the present invention provides a method for preparing the organosilicon composite polyacrylic acid flame retardant material described in the third aspect, the method comprising: (1) Apply polyacrylic acid-based fire-retardant coating to the upper and lower surfaces of the modified silicone foam layer to obtain an intermediate; (2) The intermediate is cured to obtain the organosilicon composite polyacrylic acid flame retardant material; In step (1), the polyacrylic fire retardant coating is the polyacrylic fire retardant coating described in the second aspect.

[0010] Through the above technical solution, the present invention has at least the following advantages compared with the prior art: (1) The method for preparing polyacrylic acid-based fire retardant coating provided by the present invention uses a combination of phosphorus-containing flame retardant and boron-containing flame retardant in a specific weight ratio as phosphorus-boron flame retardant, and controls the ratio of acrylate phosphate monomer, the phosphorus-boron flame retardant and the inorganic filler. The interfacial interaction between the polyacrylic acid-based fire retardant coating and the foam is significantly enhanced, and it can form a ceramicized carbon layer at high temperature.

[0011] (2) The polyacrylic acid-based fire retardant coating provided by the present invention can ensure good adhesion between the coating and the foam layer when applied to the silicone composite polyacrylic acid flame retardant material, thus producing a silicone composite polyacrylic acid flame retardant material with excellent fireproof and heat insulation effects.

[0012] (3) The organosilicon composite polyacrylic acid flame retardant material provided by the present invention has good adhesion between the modified organosilicon foam layer and the polyacrylic acid-based fireproof coating. During the high-temperature combustion pyrolysis process, the polyacrylic acid-based fireproof coating can dilute the combustible gas in the gas phase. At the same time, the ceramic carbon layer formed on its surface can effectively inhibit heat transfer, thereby protecting the modified organosilicon foam layer. This makes the organosilicon composite polyacrylic acid flame retardant material have excellent flame retardant, fireproof and heat insulation properties, and excellent smoke suppression effect.

[0013] (4) The method for preparing organosilicon composite polyacrylic acid flame retardant material provided by the present invention is simple and easy to implement. Attached Figure Description

[0014] Figure 1 These are heat release rate curves of the organosilicon composite polyacrylic acid flame retardant materials and untreated pure foam in Application Examples 1 to 4 of the present invention. Figure 2 These are the total heat release curves of the organosilicon composite polyacrylic acid flame retardant materials and untreated pure foam in Application Examples 1 to 4 of the present invention; Figure 3 This is a graph showing the total smoke production of the organosilicon composite polyacrylic acid flame retardant material and untreated pure foam in Application Examples 1 to 4 of the present invention. Figure 4 This is a graph showing the carbon monoxide production of the organosilicon composite polyacrylic acid flame retardant material and untreated pure foam in Application Examples 1 to 4 of the present invention. Figure 5 This is a graph showing the average specific extinction area of ​​the organosilicon composite polyacrylic acid flame retardant material and untreated pure foam in Application Examples 1 to 4 of the present invention. Figure 6 These are thermogravimetric analysis (TGA) test curves of the organosilicon composite polyacrylic acid flame retardant materials and untreated pure foam in Application Examples 1 to 4 of the present invention. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] As previously described, a first aspect of the present invention provides a method for preparing a polyacrylic acid-based fire-retardant coating, the method comprising: In the presence of an initiator, acrylate phosphate monomers are mixed and reacted with phosphorus boron flame retardants and inorganic fillers to obtain the polyacrylic acid-based fire-retardant coating. The phosphorus-boron flame retardant is a combination of a phosphorus-containing flame retardant and a boron-containing flame retardant in a weight ratio of 1:0.5-1.5. The weight ratio of the acrylate phosphate monomer, the phosphorus boron flame retardant, and the inorganic filler is 1:0.05-0.3:0.2-0.6.

[0017] Preferably, the weight ratio of the acrylate phosphate monomer to the initiator is 1:0.01-0.03. Under this preferred embodiment, the technical solution provided by the present invention can obtain an organosilicon composite polyacrylic acid flame-retardant material with superior flame-retardant properties, smoke suppression and toxicity reduction properties, and high-temperature resistance.

[0018] Preferably, the acrylate phosphate monomer is NTCADD®FM30 and / or NTCADD®FM20.

[0019] In a preferred embodiment, the phosphorus-containing flame retardant in the phosphorus-boron flame retardant is selected from at least one of ammonium polyphosphate, aluminum diethylphosphinate, tetraphenyl(bisphenol-A) diphosphate, and tetraphenylresorcinol diphosphate.

[0020] Preferably, the boron-containing flame retardant is selected from at least one of zinc borate, triphenyl borate, barium metaborate, and sodium tetraborate.

[0021] Preferably, the inorganic filler is selected from at least two of kaolin, montmorillonite, talc, mica, mullite, calcium metasilicate, alumina, zirconium oxide, glass microspheres, and silicon carbide.

[0022] Preferably, the inorganic filler is a combination of kaolin and alumina in a mass ratio of 4-6:1. The inventors have discovered that, under this preferred condition, the technical solution provided by the present invention can yield an organosilicon composite polyacrylic acid flame-retardant material with superior flame-retardant properties, smoke suppression and toxicity reduction properties, and high-temperature resistance.

[0023] In a preferred embodiment, the initiator is selected from at least one of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, benzophenone, 2-isopropylthioxanthone, diphenyltitanium fluoride, benzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide, and tert-butyl peroxide, preferably 2-hydroxy-2-methyl-1-phenylpropanone.

[0024] Preferably, the conditions for the mixing reaction include: a temperature of 30-60°C and a time of 3-5 minutes.

[0025] As previously stated, a second aspect of the present invention provides a polyacrylic acid-based fire-retardant coating prepared by the method described in the first aspect.

[0026] As mentioned above, a third aspect of the present invention provides a silicone composite polyacrylic acid flame retardant material, which includes a modified silicone foam layer and a polyacrylic acid-based fire-retardant coating applied to the upper and lower surfaces of the modified silicone foam layer. The polyacrylic fire-retardant coating is formed from the polyacrylic fire-retardant coating described in the second aspect; The modified organosilicon foam layer is obtained by modifying the organosilicon foam layer with silica sol.

[0027] Preferably, the average particle size of silicon oxide in the silica sol is 60-150 nm.

[0028] Preferably, the modified silicone foam layer is prepared by a method comprising the following steps: The modified silicone foam layer is obtained by contacting and mixing the silicone foam layer and the silica sol and then drying them.

[0029] Preferably, the contact mixing method is immersion.

[0030] Preferably, the drying conditions include a temperature of 50-70°C and a time of 40-80 minutes.

[0031] The preparation method of the modified organosilicon foam layer of the present invention further includes steps such as impurity removal. For example, the surface of the modified organosilicon foam layer is polished to remove surface-adhered impurities; the polishing method is selected from sandpaper polishing, grinding stone polishing, wire brush polishing, and sandblasting. Further details are omitted here and should not be construed as limiting the present invention by those skilled in the art.

[0032] In a preferred embodiment, the thickness of the polyacrylic fire-retardant coating formed on the upper surface of the modified silicone foam layer is 0.07-5 mm.

[0033] Preferably, the thickness of the polyacrylic fire-retardant coating formed on the lower surface of the modified silicone foam layer is 0.07-5 mm.

[0034] According to a preferred embodiment, the silicone foam layer is prepared by a method comprising the following steps: (S1) In the presence of a polymerization inhibitor, polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups are mixed I to obtain material I; (S2) The material I is mixed with vinyl-containing polydimethylsiloxane to obtain material II; (S3) The material II is mixed with a platinum-based catalyst and water to obtain the organosilicon foam layer.

[0035] In this invention, the "polydimethylsiloxane containing Si-H bonds" refers to a polydimethylsiloxane containing "Si-H bond" functional groups, but the polydimethylsiloxane does not contain "hydroxyl" functional groups or "vinyl" functional groups. The term "hydroxyl-containing polydimethylsiloxane" refers to a polydimethylsiloxane containing a "hydroxyl" functional group, but the polydimethylsiloxane does not contain a "Si-H bond" functional group or a "vinyl" functional group. The term "vinyl-containing polydimethylsiloxane" refers to polydimethylsiloxane containing a "vinyl" functional group, but the polydimethylsiloxane does not contain a "Si-H bond" functional group or a "hydroxyl" functional group.

[0036] Preferably, in step (S1), the polymerization inhibitor is selected from at least one of siloxane compounds, cycloalkane compounds, siloxanes containing p-hydroxyphenyl groups, and phenolic scavengers.

[0037] More preferably, the siloxane compound is selected from at least one of 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl-1,3,5,7,2,4,6,8-tetraoxatetrasiloxane, 2,4,6-trimethyl-2,4,6-trivinyl-1,3,5-trioxatrisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, and 1-ethynyl-1,1,3,3-tetramethyldisiloxane.

[0038] More preferably, the cycloalkane compound is 2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloalkane.

[0039] More preferably, the siloxane containing p-hydroxyphenyl is p-hydroxyphenyltrimethoxysilane.

[0040] More preferably, the phenol scavenging agent is at least one selected from hydroquinone, p-tert-butylcatechol, and 2,6-di-tert-butyl-p-cresol.

[0041] Preferably, in step (S1), the Si-H bond-containing polydimethylsiloxane is selected from at least one of hydrogen-terminated polydimethylsiloxane, hydrogen-terminated fluorinated polydimethylsiloxane, and hydrogen-terminated phenyl polydimethylsiloxane, and is more preferably hydrogen-terminated polydimethylsiloxane and / or hydrogen-terminated fluorinated polydimethylsiloxane.

[0042] Preferably, in step (S1), the Si-H content in the polydimethylsiloxane containing Si-H bonds is 0.5-4 wt%.

[0043] In a preferred embodiment, in step (S1), the hydroxyl-containing polydimethylsiloxane is selected from at least one of hydroxyl polydimethylsiloxane, dihydroxy-terminated polydimethylsiloxane, hydroxyphenyl polydimethylsiloxane, dihydroxypropyl fluoropolydimethylsiloxane, silanol-hydroxyphenyl silicone oil, and hydroxyl-fluorinated polydimethylsiloxane, preferably hydroxyl polydimethylsiloxane and / or dihydroxy-terminated polydimethylsiloxane.

[0044] Preferably, in step (S1), the weight ratio of the polydimethylsiloxane containing Si-H bonds to the polymerization inhibitor is 1:0.02-0.05.

[0045] Preferably, in step (S2), the vinyl-containing polydimethylsiloxane is selected from at least one of vinyl polydimethylsiloxane, vinyl-terminated polydimethylsiloxane, side-chain vinyl polydimethylsiloxane, terminal vinyl phenyl polydimethylsiloxane, and terminal vinyl fluoropolydimethylsiloxane, and is preferably vinyl polydimethylsiloxane and / or vinyl-terminated polydimethylsiloxane.

[0046] In a preferred embodiment, the kinematic viscosity of the hydroxyl-containing polydimethylsiloxane and the vinyl-containing polydimethylsiloxane at 25°C is independently 1000-20000 cSt.

[0047] Preferably, the weight ratio of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups is 1:1.25-5:1-6.

[0048] Preferably, in step (S3), the platinum-based catalyst is selected from at least one of hexachloroplatinic acid, Karstedt catalyst, and dichloro(1,5-cyclooctadiene)platinum.

[0049] In a preferred embodiment, the weight ratio of the polymerization inhibitor to the platinum-based catalyst is 1:1-3.

[0050] Preferably, in step (S3), the amount of water used is 0.05-0.1 mL relative to 1 g of the polydimethylsiloxane containing Si-H bonds.

[0051] This invention does not impose special requirements on the reaction conditions of Mix I, Mix II, and Mix III; it only requires controlling the reaction conditions to ensure that the raw materials are mixed uniformly. Further details are omitted here, and those skilled in the art should not interpret this as a limitation of the invention.

[0052] As previously described, a fourth aspect of the present invention provides a method for preparing the organosilicon composite polyacrylic acid flame retardant material described in the third aspect, the method comprising: (1) Apply polyacrylic acid-based fire-retardant coating to the upper and lower surfaces of the modified silicone foam layer to obtain an intermediate; (2) The intermediate is cured to obtain the organosilicon composite polyacrylic acid flame retardant material; In step (1), the polyacrylic fire retardant coating is the polyacrylic fire retardant coating described in the second aspect.

[0053] It should be noted that in this invention, the plane containing the long side of the modified silicone foam layer is taken as the horizontal reference plane, the side away from the ground is called the upper surface, and the side facing the ground is called the lower surface.

[0054] Preferably, in step (1), the amount of the polyacrylic fire retardant coating is controlled so that the thickness of the polyacrylic fire retardant coating formed on the upper surface of the modified silicone foam layer is 0.07-5 mm.

[0055] Preferably, in step (1), the amount of the polyacrylic fire retardant coating is controlled, and the thickness of the polyacrylic fire retardant coating formed on the lower surface of the modified silicone foam layer is 0.07-5 mm.

[0056] In a preferred embodiment, in step (1), the coating method is selected from one of brush coating, spray coating and dip coating.

[0057] Preferably, in step (1), the curing process is carried out under a UV lamp with a power of 60-90W and a wavelength of 300-400nm.

[0058] Preferably, the curing time is 20-40 seconds.

[0059] The preparation method of the organosilicon composite polyacrylic acid flame retardant material of the present invention further includes steps such as drying, for example, drying the material obtained by the curing treatment; the drying temperature is 60-100℃ and the time is 0.5-24h. Further details are omitted here, and those skilled in the art should not construe this as a limitation of the present invention.

[0060] The present invention will be described in detail below through examples. In the following examples, unless otherwise specified, the instruments, medicines and reagents used are all conventional commercially available products.

[0061] Polydimethylsiloxanes containing Si-H bonds: Hydrogen-terminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70900-21-9; the Si-H content is 1.6 wt%. Hydrogen-terminated fluorinated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 115361-68-7; the Si-H content is 3wt%.

[0062] Hydroxyl-containing polydimethylsiloxane: Hydroxyhydroxy polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70131-67-8; kinematic viscosity at 25°C is 4000 cSt; Dihydroxy-terminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 70131-67-8; kinematic viscosity at 25°C is 5000 cSt.

[0063] Vinyl-containing polydimethylsiloxanes: Vinyl polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 53529-60-5; kinematic viscosity at 25°C is 10000 cSt; Vinyl-terminated polydimethylsiloxane: purchased from China Xin'an Chemical Group Co., Ltd., CAS No. 68083-19-2; kinematic viscosity at 25°C is 10000 cSt.

[0064] Silica sol: purchased from Henan Hengyang Refractory Materials Co., Ltd., wherein the average particle size of silicon oxide is 150nm.

[0065] In the following examples, room temperature refers to a temperature of 23±2℃.

[0066] Preparation Example 1 Preparation of organosilicon foam layer Z-1: (S1) In the presence of a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane), polydimethylsiloxane containing Si-H bonds (hydrogen-terminated polydimethylsiloxane, 3g) and polydimethylsiloxane containing hydroxyl groups (hydroxyl polydimethylsiloxane) are added to a reaction vessel and mechanically stirred for 3 minutes to mix I, to obtain material I; (S2) Then, material I is stirred with vinyl-containing polydimethylsiloxane (vinyl polydimethylsiloxane) for 3 minutes to form mixture II, thus obtaining material II; (S3) Continue stirring material II with platinum-based catalyst (Karstedt catalyst) and water for 5 minutes to mix III, and obtain organosilicon foam layer Z-1; The weight ratio of polydimethylsiloxane containing Si-H bonds to the polymerization inhibitor is 1:0.04. The weight ratio of polydimethylsiloxane containing Si-H bonds, polydimethylsiloxane containing hydroxyl groups, and polydimethylsiloxane containing vinyl groups is 1:5:4. The weight ratio of polymerization inhibitor to platinum-based catalyst is 1:1; The amount of water used is 0.08 mL relative to 1 g of polydimethylsiloxane containing Si-H bonds.

[0067] Preparation of modified organosilicon foam layer Z-1: The aforementioned organosilicon foam layer Z-1 was completely immersed in silica sol to allow the two to come into contact and mix. The mixed organosilicon foam layer was then transferred to a 60°C oven and dried for 10 minutes. After drying, it was removed from the oven and then placed back into the oven to dry for another 30 minutes. Subsequently, the surface of the dried intermediate was polished with 800-mesh (Chinese standard sieve) sandpaper to remove impurities adhering to the surface, thus obtaining the modified organosilicon foam layer Z-1.

[0068] Preparation Example 2 Preparation of organosilicon foam layer Z-2: (S1) In the presence of a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane), polydimethylsiloxane containing Si-H bonds (hydrogen-terminated fluorinated polydimethylsiloxane, 3g) and polydimethylsiloxane containing hydroxyl groups (dihydroxy-terminated polydimethylsiloxane) are added to a reaction vessel and mechanically stirred for 3 minutes to mix I, obtaining material I; (S2) Then, material I is stirred with vinyl-containing polydimethylsiloxane (vinyl-terminated polydimethylsiloxane) for 5 minutes to form mixture II, thus obtaining material II; (S3) Continue stirring material II with platinum-based catalyst (Karstedt catalyst) and water for 5 minutes to carry out mixing III, to obtain organosilicon foam layer Z-2; The weight ratio of polydimethylsiloxane containing Si-H bonds to the polymerization inhibitor is 1:0.02. The weight ratio of polydimethylsiloxane containing Si-H bonds, polydimethylsiloxane containing hydroxyl groups, and polydimethylsiloxane containing vinyl groups is 1:5:5. The weight ratio of the polymerization inhibitor to the platinum-based catalyst is 1:3; The amount of water used is 0.05 mL relative to 1 g of polydimethylsiloxane containing Si-H bonds.

[0069] Preparation of modified organosilicon foam layer Z-2: The aforementioned organosilicon foam layer Z-2 was completely immersed in silica sol to allow the two to come into contact and mix. The mixed organosilicon foam layer was then transferred to a 60°C oven and dried for 10 minutes. After drying, it was removed from the oven and then placed back into the oven to dry for another 30 minutes. Subsequently, the surface of the dried intermediate was polished with 800-mesh (Chinese standard sieve) sandpaper to remove impurities adhering to the surface, thus obtaining the modified organosilicon foam layer Z-2.

[0070] The following examples illustrate the preparation method of the polyacrylic acid-based fire-retardant coating provided by the present invention. Example 1 In the presence of an initiator (2-hydroxy-2-methyl-1-phenylpropanone), 6.5 g of acrylate phosphate monomer (NTCADD®FM30) was mixed with a phosphorus boron flame retardant and an inorganic filler (a combination of kaolin and alumina) and reacted (at a temperature of 30°C for 5 min) to obtain a polyacrylic acid-based fire-retardant coating.

[0071] Examples 2 to 4 were carried out using a method similar to that of Example 1, except that the types and amounts of raw materials were different, as listed in Table 1.

[0072] Table 1

[0073] Example 5 The procedure was carried out in a similar manner to Example 1, except that the amount of phosphate acrylate monomer was kept constant, and the weight ratio of phosphate acrylate monomer to initiator was adjusted to 1:0.05. Everything else is the same, resulting in polyacrylic acid-based fire-retardant coating S-5.

[0074] Comparative Example 1 The procedure was carried out in a similar manner to Example 1, except that the total amount of ammonium polyphosphate and zinc borate was kept constant, and the weight ratio of ammonium polyphosphate and zinc borate was adjusted to 1:0.2. Everything else is the same, resulting in polyacrylic acid-based fire-retardant coating DS-1.

[0075] Comparative Example 2 The procedure was carried out in a similar manner to Example 1, except that the amount of acrylate phosphate monomer was kept constant, and the weight ratio of acrylate phosphate monomer, phosphorus boron flame retardant and inorganic filler was adjusted to 1:0.5:0.1. Everything else is the same, resulting in polyacrylic acid-based fire-retardant coating DS-2.

[0076] Comparative Example 3 The preparation was carried out in a similar manner to that of Example 1, except that an equal weight of aluminum hydroxide was used instead of zinc borate; Everything else is the same, resulting in polyacrylic acid-based fire-retardant coating DS-3.

[0077] The following application examples illustrate the preparation method of the organosilicon composite polyacrylic acid flame retardant material provided by the present invention. Application Example 1 (1) Apply polyacrylic acid fire retardant coating S-1 to the upper and lower surfaces of modified silicone foam layer Z-1 by brushing to obtain an intermediate; The amount of polyacrylic acid-based fire retardant coating was controlled so that the thickness of the polyacrylic acid-based fire retardant coating formed on the upper and lower surfaces of the modified silicone foam layer Z-1 was 0.07 mm. (2) At room temperature, the intermediate was then placed under a UV lamp with a power of 80W and a wavelength of 365nm for curing treatment (time of 30s), and then transferred to an oven for drying treatment (temperature of 80℃, time of 1h) to remove moisture, and finally obtained organosilicon composite polyacrylic acid flame retardant material Y-1.

[0078] Application Example 2 (1) Apply polyacrylic acid fire retardant coating S-2 to the upper and lower surfaces of modified silicone foam layer Z-2 by brushing to obtain an intermediate; The amount of polyacrylic acid-based fire retardant coating was controlled so that the thickness of the polyacrylic acid-based fire retardant coating formed on the upper and lower surfaces of the modified silicone foam layer Z-2 was 0.15 mm. (2) At room temperature, the intermediate was then placed under an 80W UV lamp with a wavelength of 365nm for curing (30s), and then transferred to an oven for drying (80℃, 1.5h) to remove moisture, and finally obtained organosilicon composite polyacrylic acid flame retardant material Y-2.

[0079] Application Example 3 (1) Apply polyacrylic acid fire retardant coating S-3 to the upper and lower surfaces of modified silicone foam layer Z-1 by brushing to obtain an intermediate; The amount of polyacrylic acid-based fire retardant coating was controlled so that the thickness of the polyacrylic acid-based fire retardant coating formed on the upper and lower surfaces of the modified silicone foam layer Z-1 was 0.35 mm. (2) At room temperature, the intermediate was then placed under an 80W UV lamp with a wavelength of 365nm for curing (30s), and then transferred to an oven for drying (80℃, 2h) to remove moisture, and finally obtained organosilicon composite polyacrylic acid flame retardant material Y-3.

[0080] Application Example 4 (1) Apply polyacrylic acid fire retardant coating S-4 to the upper and lower surfaces of modified silicone foam layer Z-2 by brushing to obtain an intermediate; The amount of polyacrylic acid-based fire retardant coating was controlled so that the thickness of the polyacrylic acid-based fire retardant coating formed on the upper and lower surfaces of the modified silicone foam layer Z-2 was 0.5 mm. (2) At room temperature, the intermediate was then placed under an 80W UV lamp with a wavelength of 365nm for curing (30s), and then transferred to an oven for drying (80℃, 2h) to remove moisture, and finally obtained organosilicon composite polyacrylic acid flame retardant material Y-4.

[0081] Application Example 5 to Comparative Application Example 3 The process was carried out in a similar manner to Application Example 1, except that polyacrylic fire retardant coating S-1 was replaced with polyacrylic fire retardant coating S-5, polyacrylic fire retardant coating DS-1, polyacrylic fire retardant coating DS-2, and polyacrylic fire retardant coating DS-3 of equal weight. The rest are the same, and organosilicon composite polyacrylic acid flame retardant materials Y-5, DY-1, DY-2, and DY-3 are obtained respectively.

[0082] Test case The organosilicon composite polyacrylic acid flame retardant materials prepared in the corresponding use cases and comparative application examples were subjected to performance tests, including: heat release rate, total heat release, total smoke production, carbon monoxide production, average specific extinction area, and thermogravimetric analysis. The test results were compared with those of untreated pure polydimethylsiloxane foam (hereinafter referred to as "pure foam"). The test results are shown in Table 2.

[0083] The preparation method of pure foam is as follows: First, 8g of hydrogen-terminated polydimethylsiloxane-1, 40g of hydroxyl polydimethylsiloxane, and a polymerization inhibitor (2,4,6,8-tetramethyl-2,4,6,8-tetramethyl-1,3,5,7,2,4,6,8-tetramethyltetracycloane) were placed in a reaction vessel and mechanically mixed at 900 rpm for 3 min. Then, 40g of vinyl polydimethylsiloxane was added to the mixture, and the mixture was continuously treated at a stirring rate of 1200 rpm for 5 min to form a prepolymer. Next, 0.4g of Karstedt catalyst (mass concentration of 5000 ppm) was injected into the prepolymer, and the mixture was stirred for 30 s to complete catalytic activation. The activated system was transferred to a pre-designed mold and allowed to stand at room temperature for 15 min to build a three-dimensional network structure. Finally, the foamed sample was placed in a 60℃ constant temperature oven for 4 h for heat treatment to promote complete cross-linking and curing of the organosilicon network.

[0084] The relevant testing methods are as follows: Heat release rate, total heat release, total smoke production, carbon monoxide production, and average specific extinction area were all tested using a cone calorimeter, in accordance with ISO 5660, with a test requirement of 35 kW.

[0085] Thermogravimetric analysis: Tests were performed using a TGA Q500 thermogravimetric analyzer under a nitrogen atmosphere at a heating rate of 10℃·min. -1 .

[0086] Table 2

[0087] The present invention exemplarily in Figure 1 The diagram provides heat release rate curves for the silicone-composite polyacrylic acid flame-retardant materials and untreated pure foam used in Application Examples 1 to 4; Figure 1 It can be seen that the peak heat release rates of samples Y-1 to Y-4 are between 130 and 250 kW / m². 2 The peak heat release rate of the untreated pure foam sample was 452.2 kW / m². 2 This demonstrates that the organosilicon composite polyacrylic acid flame retardant material prepared by this invention exhibits excellent flame retardant properties.

[0088] The present invention exemplarily in Figure 2 The diagram provides total heat release curves for the silicone-composite polyacrylic acid flame-retardant materials and untreated pure foam used in Application Examples 1 to 4; Figure 2 It can be seen that the total heat release equilibrium values ​​of samples Y-1 to Y-4 are between 50 and 90 MJ / m². 2 The total heat release value of the untreated pure foam sample exceeded 120 MJ / m². 2 This demonstrates that the organosilicon composite polyacrylic acid flame retardant material prepared by this invention exhibits excellent flame retardant properties.

[0089] The present invention exemplarily in Figure 3 The diagram provides total smoke production curves for application examples 1 to 4 of the silicone-composite polyacrylic acid flame-retardant material and untreated pure foam; Figure 3 It can be seen that the total smoke production of samples Y-1 to Y-4 is between 12 and 23 m³. 2 Between, the total smoke production of the untreated pure foam sample exceeded 39m³. 2 This demonstrates that the organosilicon composite polyacrylic acid flame retardant material prepared by this invention exhibits excellent smoke suppression performance.

[0090] The present invention exemplarily in Figure 4 The diagram provides carbon monoxide production curves for application examples 1 to 4 of silicone-composite polyacrylic acid flame-retardant materials and untreated pure foam; Figure 4It can be seen that the carbon monoxide production of samples Y-1 to Y-4 ranged from 0.001 to 0.003 g / s, while the carbon monoxide production of the untreated pure foam sample was close to 0.006 g / s. This indicates that the organosilicon composite polyacrylic acid flame retardant material prepared in this invention exhibits good smoke suppression and toxicity reduction properties.

[0091] The present invention exemplarily in Figure 5 The diagram provides average specific extinction area curves for the silicone-composite polyacrylic acid flame-retardant materials used in Application Examples 1 to 4, compared to untreated pure foam; Figure 5 It can be seen that the average specific extinction area of ​​samples Y-1 to Y-4 is between 260 and 400 m². 2 The average specific extinction area of ​​the untreated pure foam sample was close to 590 m² / kg. 2 / kg. This demonstrates that the organosilicon composite polyacrylic acid flame retardant material prepared by this invention exhibits good high-temperature resistance.

[0092] The present invention exemplarily in Figure 6 Thermogravimetric analysis (TGA) curves of the silicone-composite polyacrylic acid flame-retardant materials and untreated pure foam used in Application Examples 1 to 4 are provided; Figure 6 It can be seen that the remaining weight of samples Y-1 to Y-4 is between 60% and 75%, while the remaining weight of the untreated pure foam sample is close to 54%. This indicates that the organosilicon composite polyacrylic acid flame retardant material prepared by this invention exhibits good high-temperature resistance.

[0093] The results above show that the technical solution provided by this invention improves the surface properties of polyacrylic fire-retardant coatings. It not only enhances the hydrophilicity of the silicone composite polyacrylic flame-retardant material, solving the coating adhesion problem caused by the hydrophobicity of PDMS, but also strengthens its interfacial bonding with the modified silicone foam layer, enhances the interfacial interaction with the foam, and ensures stable coating adhesion.

[0094] Furthermore, the organosilicon composite polyacrylic acid flame retardant material prepared by the technical solution provided by the present invention has excellent fire resistance and heat insulation properties, and significantly improves the flame retardant performance, smoke suppression and toxicity reduction performance and high temperature resistance of PDMS foam, and can be applied to the fields of flame retardant heat insulation and thermal protection of energy storage batteries.

[0095] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a polyacrylic acid-based fire-retardant coating, characterized in that, The method includes: In the presence of an initiator, acrylate phosphate monomers are mixed and reacted with phosphorus boron flame retardants and inorganic fillers to obtain the polyacrylic acid-based fire-retardant coating. The phosphorus-boron flame retardant is a combination of a phosphorus-containing flame retardant and a boron-containing flame retardant in a weight ratio of 1:0.5-1.

5. The weight ratio of the acrylate phosphate monomer, the phosphorus boron flame retardant, and the inorganic filler is 1:0.05-0.3:0.2-0.

6.

2. The method according to claim 1, wherein, The weight ratio of the acrylate phosphate monomer to the initiator is 1:0.01-0.

03.

3. The method according to claim 1 or 2, wherein, In the phosphorus-boron flame retardant, the phosphorus-containing flame retardant is selected from at least one of ammonium polyphosphate, aluminum diethylphosphinate, tetraphenyl(bisphenol-A) diphosphate, and tetraphenylresorcinol diphosphate; And / or, the boron-containing flame retardant is selected from at least one of zinc borate, triphenyl borate, barium metaborate, and sodium tetraborate.

4. The method according to claim 1 or 2, wherein, The inorganic filler is selected from at least two of the following: kaolin, montmorillonite, talc, mica, mullite, calcium metasilicate, alumina, zirconium oxide, glass microspheres, and silicon carbide. And / or, the initiator is selected from at least one of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone, benzophenone, 2-isopropylthioxanthone, diphenyltitanium fluoride, benzoyl peroxide, azobisisobutyronitrile, di-tert-butyl peroxide, and tert-butyl peroxide.

5. A polyacrylic acid-based fire-retardant coating prepared by the method according to any one of claims 1-4.

6. A silicone-composite polyacrylic acid flame-retardant material, characterized in that, The organosilicon composite polyacrylic acid flame retardant material includes a modified organosilicon foam layer and a polyacrylic acid-based fire-retardant coating applied to the upper and lower surfaces of the modified organosilicon foam layer. The polyacrylic fire-retardant coating is formed from the polyacrylic fire-retardant coating according to claim 5; The modified organosilicon foam layer is obtained by modifying the organosilicon foam layer with silica sol.

7. The organosilicon composite polyacrylic acid flame retardant material according to claim 6, wherein, The thickness of the polyacrylic acid-based fire-retardant coating formed on the upper surface of the modified silicone foam layer is 0.07-5 mm; And / or, the thickness of the polyacrylic fire-retardant coating formed on the lower surface of the modified silicone foam layer is 0.07-5 mm.

8. The organosilicon composite polyacrylic acid flame retardant material according to claim 6 or 7, wherein, The silicone foam layer is prepared by a method comprising the following steps: (S1) In the presence of a polymerization inhibitor, polydimethylsiloxane containing Si-H bonds and polydimethylsiloxane containing hydroxyl groups are mixed I to obtain material I; (S2) The material I is mixed with vinyl-containing polydimethylsiloxane to obtain material II; (S3) The material II is mixed with a platinum-based catalyst and water to obtain the organosilicon foam layer.

9. The organosilicon composite polyacrylic acid flame retardant material according to claim 8, wherein, The weight ratio of the polydimethylsiloxane containing Si-H bonds, the polydimethylsiloxane containing hydroxyl groups, and the polydimethylsiloxane containing vinyl groups is 1:1.25-5:1-6.

10. A method for preparing the organosilicon composite polyacrylic acid flame retardant material according to any one of claims 6-9, characterized in that, The method includes: (1) Apply polyacrylic acid-based fire-retardant coating to the upper and lower surfaces of the modified silicone foam layer to obtain an intermediate; (2) The intermediate is cured to obtain the organosilicon composite polyacrylic acid flame retardant material; In step (1), the polyacrylic fire retardant coating is the polyacrylic fire retardant coating as described in claim 5.

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