Flame-retardant organic impregnant and method for its preparation

Abstract

The application discloses a kind of flame-retardant type organic impregnating agent and preparation method thereof.The flame-retardant type organic impregnating agent includes the following mass fraction components: monofunctional acrylate monomer 40-50 parts, difunctional acrylate monomer 25-35 parts, multifunctional acrylate monomer 10-15 parts, POSS-NPP-EMA flame retardant 10-15 parts, surfactant 0.05-0.5 parts, polymerization inhibitor 0.1-0.2 parts, initiator 0.3-0.8 parts.The application uses a new silicon-phosphorus-nitrogen synergistic flame retardant as a reactive monomer, which is chemically bonded and cured with acrylate monomers through heating, giving the impregnating agent high heat resistance, low shrinkage and high flame retardancy, and at the same time, the flame-retardant impregnating agent also has excellent sealing property for castings.

Description

Technical Field

[0001] This invention relates to the field of acrylate impregnation agent preparation technology, specifically to a flame-retardant organic impregnation agent and its preparation method, and more specifically to a high-temperature resistant, low-shrinkage acrylate impregnation agent with flame-retardant properties. Background Technology

[0002] During the casting process, leaks, cracks, and porosity are inevitable, causing castings to lose their sealing properties and become scrap. The most effective measure for sealing leaks and reinforcing is to use vacuum impregnation agents, allowing castings that were originally destined for scrap to be recycled. Impregnating agents are liquid substances formulated from inorganic or organic materials. Currently, organic impregnating agents have replaced inorganic impregnating agents, especially acrylate-based vacuum impregnating agents, which are now the preferred impregnating agents. Acrylate-based vacuum impregnating agents are mainly composed of acrylate monomers with different functionalities, supplemented by initiators, polymerization inhibitors, and surfactants. Although acrylate monomers and their thermosetting materials have good chemical stability, mechanical properties, and weather resistance, they generally lack flame retardant properties and have a very low limiting oxygen index (LOI), posing safety hazards during production, use, and storage, thus greatly limiting their application.

[0003] Adding flame retardants is an important method to improve the flame retardancy of polymer materials. Among them, halogenated flame retardants have advantages such as high flame retardant efficiency, low addition amount, and minimal impact on substrate performance, and occupy an important position in the flame retardant field. CN104387522A reports a flame-retardant acrylate-type organic impregnating agent for sealing and reinforcement and its preparation method. This invention significantly improves the flame retardant performance of the impregnating agent polymer by copolymerizing a brominated flame retardant onto the molecular chain of a methacrylate monomer, with the oxygen index of the cured product reaching over 27%. However, halogenated flame retardants themselves are toxic and easily produce toxic substances such as dense smoke, dioxins, and hydrogen halides when burned, posing a threat to the environment and human health. Currently, their application in electronic products and new energy vehicles is restricted.

[0004] Phosphorus-based flame retardants are environmentally friendly and low in toxicity, possess excellent flame-retardant properties, act as plasticizers, and improve the processing and flexibility of materials. On the other hand, organosilicon is an environmentally friendly flame retardant that not only effectively blocks heat and mass exchange but also significantly improves the thermal stability and heat resistance of materials. Therefore, phosphorus-silicon synergistic flame retardants are one of the main research trends in the industry. CN116217803A reports a cross-linked phosphorus-silicon synergistic flame retardant and a flame-retardant polystyrene resin. This invention obtains a cross-linked phosphorus-silicon synergistic flame retardant by polymerizing a self-made vinyl diphenyl phosphate with vinylsilane and divinylbenzene. This cross-linked phosphorus-silicon synergistic flame retardant is added to non-flame-retardant polystyrene to increase the limiting oxygen index and impart flame retardancy.

[0005] Typically, existing practical flame retardants require a high addition amount (>30%) to achieve the flame retardant performance index. However, when used in acrylic impregnation agents, a high addition amount of flame retardant often results in excessive viscosity of the impregnation agent, leading to a decrease in the thermal stability of the thermosetting material and a deterioration in its physical and mechanical properties. Therefore, the development of environmentally friendly, low-toxicity, and highly efficient flame-retardant acrylic impregnation agents is of great application significance. Summary of the Invention

[0006] The purpose of this invention is to provide a flame-retardant organic impregnating agent and its preparation method.

[0007] This invention uses a novel silicon-phosphorus-nitrogen synergistic flame retardant as a reactive monomer, which is chemically bonded and cured with acrylate monomers by heating, giving the impregnating agent high heat resistance, low shrinkage and high flame retardancy. At the same time, the flame retardant impregnating agent also has excellent sealing properties for castings.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This invention provides a flame-retardant organic impregnating agent, wherein the flame-retardant organic impregnating agent comprises the following components in parts by weight:

[0010] 40-50 parts of monofunctional acrylate monomer, 25-35 parts of difunctional acrylate monomer, 10-15 parts of polyfunctional acrylate monomer, 10-15 parts of POSS-NPP-EMA flame retardant, 0.05-0.5 parts of surfactant, 0.1-0.2 parts of polymerization inhibitor, and 0.3-0.8 parts of initiator;

[0011] The structural formula of the POSS-NPP-EMA flame retardant is as follows:

[0012]

[0013] In the formula, R is selected from C1 to C10 alkyl, phenyl, acetoxyethyl or... ;

[0014] Y is selected from H, alkyl or phenyl groups from C1 to C10;

[0015] Z is either O or NH;

[0016] n is 1 or 2.

[0017] In the name "POSS-NPP-EMA flame retardant", "POSS" refers to the polyhedral oligomeric silsesquioxane unit in the structural formula; "NPP" refers to the phenyl phosphate diamide unit (phosphoramide unit with phenyl group) in the structural formula, where N represents "nitrogen element", one P represents "phosphorus element" and the other P represents "phenyl"; "EMA" refers to the methacryloyloxy unit in the structural formula.

[0018] According to the flame-retardant organic impregnating agent of the present invention, preferably, R is selected from C1 to C6 alkyl, phenyl, acetoxyethyl or... The C1 to C6 alkyl groups are more preferably methyl, ethyl, or cyclohexyl.

[0019] In the flame-retardant organic impregnating agent according to the present invention, preferably, R is methyl or phenyl.

[0020] In the flame-retardant organic impregnating agent according to the present invention, preferably, Y is selected from H, C1 to C6 alkyl groups, or phenyl groups. The C1 to C6 alkyl groups are more preferably selected from methyl or cyclohexyl groups.

[0021] According to the flame-retardant organic impregnating agent of the present invention, preferably, the structural formula of the POSS-NPP-EMA flame retardant is selected from any one of the following:

[0022] ,

[0023] ,

[0024] ,

[0025] ,

[0026] ,

[0027] ,

[0028] .

[0029] According to the flame-retardant organic impregnating agent of the present invention, preferably, the monofunctional acrylate monomer is selected from alkyl esters having 5-25 carbon atoms; the present invention preferably selects at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, octyl methacrylate, decyl methacrylate, isodecyl methacrylate, isobornyl methacrylate, lauryl methacrylate, diethylene glycol ethyl ether methacrylate, tridecanol methacrylate, tetradecanol methacrylate, and octadecyl methacrylate.

[0030] According to the flame-retardant organic impregnating agent of the present invention, preferably, the monofunctional acrylate monomer is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, isobornyl methacrylate, tridecyl methacrylate, lauryl methacrylate, and isodecanyl methacrylate.

[0031] According to the flame-retardant organic impregnating agent of the present invention, preferably, the difunctional acrylate is selected from dialkyl esters having 10-25 carbon atoms; the present invention preferably selects at least one of dimethyl acrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethyl diacrylate, 1,10-decanediol dimethacrylate, triethylene glycol dimethacrylate, and tripropylene glycol diacrylate.

[0032] According to the flame-retardant organic impregnating agent of the present invention, preferably, the difunctional acrylate is selected from at least one of 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethyl diacrylate, 1,10-decanediol dimethyl acrylate, and triethylene glycol dimethyl acrylate.

[0033] According to the flame-retardant organic impregnating agent of the present invention, preferably, the multifunctional acrylate is selected from one of tri- or tetraalkyl esters having 12-30 carbon atoms; the present invention preferably selects at least one of trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), pentaerythritol triacrylate (PETA), and pentaerythritol tetraacrylate (PET4A).

[0034] According to the flame-retardant organic impregnating agent of the present invention, preferably, the initiator is selected from peroxide or azo compound initiators; for example, at least one selected from lauroyl peroxide, diisopropylbenzene peroxide, tert-butyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, and dimethyl azobisisobutyrate.

[0035] According to the flame-retardant organic impregnating agent of the present invention, preferably, the initiator is azobisisoheptanenitrile or / and dimethyl azobisisobutyrate.

[0036] According to the flame-retardant organic impregnating agent of the present invention, preferably, the polymerization inhibitor is selected from at least one of hydroquinone, benzoquinone, anthraquinone, 1,4-naphthoquinone, tert-butylcatechol, and 2,6-dibutyl-p-cresol.

[0037] According to the flame-retardant organic impregnating agent of the present invention, preferably, the polymerization inhibitor is 2,6-dibutyl-p-cresol.

[0038] According to the flame-retardant organic impregnating agent of the present invention, preferably, the surfactant is selected from at least one of polyoxyethylene sorbitan monooleate, polyoxyethylene hexadecyl ether, isotridecyl polyoxyethylene polyoxypropylene ether, fatty acid polyoxyethylene ester or polyethylene glycol laurate, and polyoxyethylene castor oil.

[0039] Another invention provides a method for preparing any one of the flame-retardant organic impregnating agents, wherein the preparation method includes the following steps:

[0040] The monofunctional acrylate monomer, difunctional acrylate monomer, polyfunctional acrylate monomer, POSS-NPP-EMA flame retardant, surfactant, polymerization inhibitor, and initiator are stirred and mixed evenly at room temperature to obtain the flame-retardant organic impregnating agent.

[0041] According to the preparation method of the present invention, preferably, the POSS-NPP-EMA flame retardant is prepared by the following steps:

[0042]

[0043] 1) RSiCl3, acetone and water are reacted to obtain R7T7(OH)3 (heptameric R-based silsesquioxane trisilyl alcohol); R is as defined in the above flame retardant structural formula;

[0044] 2) Under the action of triethylamine, R7T7(OH)3 reacts with silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 to obtain R7POSS-NHY; X is -CH2CH2CH2NHY, and Y is as defined in the above flame retardant structural formula;

[0045] 3) Under the action of triethylamine, R7POSS-NHY reacts with phenyl dichlorophosphate (PDCP), and then reacts with amino-substituted methacrylate / amide (referring to amino-substituted methacrylate or amino-substituted methacrylamide) to obtain the POSS-NPP-EMA flame retardant.

[0046] The preparation method of the impregnating agent provided by the present invention includes two stages: the first stage is to chemically graft PDCP with nano-sized polyhedral oligomeric silsesquioxane (POSS) and amino-substituted methacrylate / amide to prepare flame-retardant POSS-NPP-EMA reactive monomers; the second stage is to blend methacrylate monomers with different functionalities, initiators and polymerization inhibitors with POSS-NPP-EMA reactive monomers to form a uniform mixture to obtain a flame-retardant acrylate organic impregnating agent.

[0047] According to the preparation method of the present invention, preferably, the RSiCl3 is selected from methyltrichlorosilane, ethyltrichlorosilane, cyclohexyltrichlorosilane, phenyltrichlorosilane, acetoxyethyltrichlorosilane, and 2-methyl-2-acrylate-3-(trichlorosilyl)propyl ester. .

[0048] According to the preparation method of the present invention, preferably, the RSiCl3 is methyltrichlorosilane or phenyltrichlorosilane.

[0049] According to the preparation method of the present invention, preferably, the silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is selected from γ-aminopropyltriethoxysilane (KH550), 3-(methylamino)propyltrimethoxysilane, 3-( N (-cyclohexylamino)propyltrimethoxysilane (KH106) N -Phenylacetyl-3-aminopropyltrimethoxysilane or N - n-Butyl-3-aminopropyltriethoxysilane.

[0050] According to the preparation method of the present invention, preferably, the silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is γ-aminopropyltriethoxysilane (KH550) or 3-( N -cyclohexylaminopropyltrimethoxysilane (KH106).

[0051] According to the preparation method of the present invention, preferably, the amino-substituted methacrylate / amide is selected from 2-aminoethyl methacrylate hydrochloride, 2-(tert-butylamino)ethyl methacrylate, N 2-(2-aminoethyl)methacrylamide hydrochloride (AEMA) or N 3-(3-aminopropyl)methacrylamide hydrochloride (APMA).

[0052] According to the preparation method of the present invention, preferably, the amino-substituted methacrylate / amide is 2-aminoethyl methacrylate hydrochloride or... N 2-(2-aminoethyl)methacrylamide hydrochloride (AEMA).

[0053] According to the preparation method of the present invention, preferably, in step 1), RSiCl3 and acetone are mixed, and deionized water is slowly added under stirring and refluxed for reaction; after the reaction is completed, the solid is separated, washed with acetone and deionized water until neutral, and dried to obtain R7T7(OH)3.

[0054] In step 1), the amounts of acetone and deionized water are in excess, for example, RSiCl3:acetone:deionized water = 2:5:10. This invention does not limit this amount.

[0055] According to the preparation method of the present invention, preferably, in step 2), R7T7(OH)3 and triethylamine are added to tetrahydrofuran, and the silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is added dropwise under stirring, and the reaction is carried out under reflux; after the reaction is completed, the solid is separated, washed with dilute hydrochloric acid and deionized water until neutral, and dried to obtain R7POSS-NHY.

[0056] In step 2), the amount of triethylamine and silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is in excess relative to R7T7(OH)3, and this invention does not limit this.

[0057] According to the preparation method of the present invention, preferably, in step 3), phenyl dichlorophosphate (PDCP) and triethylamine are added to dichloromethane, and R7POSS-NHY is added under stirring and the reaction is carried out at room temperature; after the reaction is completed, amino-substituted methacrylate / amide is added to continue the reaction; after the reaction is completed, triethylamine hydrochloride and dichloromethane are removed to obtain the POSS-NPP-EMA flame retardant.

[0058] According to the preparation method of the present invention, preferably, in step 3), the molar ratio of triethylamine, phenyl dichlorophosphate (PDCP), R7POSS-NHY and amino-substituted methacrylate / amide is (2.1~3.2):1:1:1.

[0059] The present invention has the following beneficial effects:

[0060] 1) Polyhedral oligomeric silsesquioxanes (POSS) possess a nanoscale structure of organic-inorganic cubic hybrid materials. During the flame retardant process, they form a carbonaceous silicate protective layer, which can effectively block the transfer of heat to the polymer interior and slow down the polymer combustion rate, thus greatly improving the flame retardancy and oxidation resistance of the polymer. When POSS is chemically bonded to the polymer chain segments of the impregnating agent, it not only improves the thermal stability, dimensional stability and molecular chain fluidity of the polymer linear structure, but also significantly improves the high temperature resistance and mechanical properties of the polymer, which is beneficial for the application of the material in a wider range.

[0061] 2) The phosphoramide structure (NPP-EMA) has phosphorus-nitrogen active components that release non-combustible gases such as N2 and NH3 at high temperatures, which block the polymer from contacting air and slow down and inhibit its combustion, thereby increasing the char yield; at the same time, it generates a large number of high-temperature thermally stable residues rich in PN cross-linking structures, which effectively inhibits the thermal decomposition of the polymer.

[0062] 3) The silicon-containing carbon layer structure formed by the phosphorus-nitrogen-silicon synergistic flame retardant is more dense and stable than the conventional phosphorus or silicon-based catalytic carbon layer, with stronger oxidation resistance and better oxygen isolation and heat insulation, thus achieving a synergistic flame retardant effect. Therefore, an addition of 10% is enough to make the polymer reach the level of flame retardant material.

[0063] 4) The POSS-NPP-EMA flame retardant of the present invention is also a reactive acrylic monomer. During the thermosetting process of the impregnating agent, it forms polymer segments through chemical bonding with other acrylic monomers, which effectively avoids the migration of the flame retardant and ensures the long-lasting flame retardant performance of the cured material. The acrylic structure of the flame retardant and the flexible carbon chain connection between POSS and phosphoramide make it compatible with the impregnating agent, thus not changing the inherent excellent properties of the impregnating agent. Detailed Implementation

[0064] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0065] All numerical specifications in this invention (e.g., temperature, time, concentration, and weight, including ranges for each) are generally approximate values ​​that may be changed (+) or (-) in increments of 0.1 or 1.0. All numerical specifications are to be understood as being preceded by the term "about".

[0066] Example 1

[0067] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0068] 9 parts hydroxyethyl methacrylate, 40 parts lauryl methacrylate, 25 parts 1,10-decanediol dimethacrylate, 10 parts trimethylolpropane triacrylate, 15 parts Me7POSS-HNPP-OEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0069] The structural formula and preparation method of Me7POSS-HNPP-OEMA are as follows:

[0070]

[0071] 1) Add 20 mL of CH3SiCl3 and 50 mL of acetone solution to the reactor, and slowly add 100 mL of deionized water while stirring. Reflux for 24 hours. Filter, wash repeatedly with acetone and deionized water until neutral, and dry to obtain a white powdery solid: Me7T7(OH)3.

[0072] 2) Add 10g Me7T7(OH)3, 100 mL triethylamine, and 200 mL tetrahydrofuran to the reactor. While stirring, add 10 mL KH550 (3-aminopropyltriethoxysilane) dropwise, and then reflux for 24 hours. Filter, wash repeatedly with dilute hydrochloric acid and deionized water until neutral, and dry to obtain a white powder solid: Me7POSS-C3H6NH2.

[0073] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor. Add 29 g of Me7POSS-C3H6NH2 while stirring. React at room temperature for 6 hours. Then add 8.3 g of 2-aminoethyl methacrylate hydrochloride and continue the reaction for 10 hours. Remove the triethylamine hydrochloride and dichloromethane to obtain a pale yellow viscous liquid: Me7POSS-HNPP-OEMA.

[0074] Example 2

[0075] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0076] 10 parts hydroxyethyl methacrylate, 34 parts isodecyl methacrylate, 35 parts 1,6-hexanediol dimethyl diacrylate, 10 parts trimethylolpropane triacrylate, 10 parts Me7POSS-NNPP-NEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0077] The structural formula and preparation method of Me7POSS-NNPP-NEMA are as follows:

[0078]

[0079] 1) The preparation of Me7T7(OH)3 is the same as in Example 1.

[0080] 2) Add 10g Me7T7(OH)3, 100 mL triethylamine, and 200 mL tetrahydrofuran to the reactor. While stirring, add 10 mL KH106 dropwise, then reflux for 24 hours. Filter, wash repeatedly with dilute hydrochloric acid and deionized water until neutral, and dry to obtain a white powder solid: Me7POSS-C3H6NHC6H 11 .

[0081] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor, and then add 33 g of Me7POSS-C3H6NHC6H while stirring. 11The reaction was carried out at room temperature for 6 hours, and then 8.4 g of AEMA was added. The reaction was continued for 10 hours to remove triethylamine hydrochloride and dichloromethane, resulting in a pale yellow viscous liquid: Me7POSS-NNPP-NEMA.

[0082] Example 3

[0083] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0084] 10 parts hydroxyethyl methacrylate, 40 parts lauryl methacrylate, 28 parts triethylene glycol dimethacrylate, 11 parts trimethylolpropane trimethacrylate, 10 parts Ph7POSS-HNPP-OEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0085] The structural formula and preparation method of Ph7POSS-HNPP-OEMA are as follows:

[0086]

[0087] 1) Add 20 mL of Ph3SiCl3 and 50 mL of acetone solution to the reactor, and slowly add 100 mL of deionized water while stirring. Reflux for 24 hours. Filter by suction, wash repeatedly with acetone and deionized water until neutral, and dry to obtain a pale yellow powdery solid: Ph7T7(OH)3.

[0088] 2) Add 10g Ph7T7(OH)3, 100 mL triethylamine and 250 mL tetrahydrofuran to the reactor, and add 10 mL KH550 dropwise while stirring. Then reflux for 24 hours. Filter by suction, wash repeatedly with dilute hydrochloric acid and deionized water until neutral, and dry to obtain a white powder solid: Ph7POSS-C3H6NH2.

[0089] 3) Add 300 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor. Add 51 g of Ph7POSS-C3H6NH2 while stirring. React at room temperature for 6 hours. Then add 8.3 g of 2-aminoethyl methacrylate hydrochloride and continue the reaction for 10 hours. Remove the triethylamine hydrochloride and dichloromethane to obtain a pale yellow viscous liquid: Ph7POSS-HNPP-OEMA.

[0090] Example 4

[0091] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0092] 10 parts hydroxyethyl methacrylate, 35 parts isodecyl methacrylate, 32 parts 1,6-hexanediol dimethyl diacrylate, 11 parts trimethylolpropane trimethacrylate, 11 parts Ph7POSS-NNPP-NEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0093] The structural formula and preparation method of Ph7POSS-NNPP-NEMA are as follows:

[0094]

[0095] 1) The preparation of Ph7T7(OH)3 is the same as in Example 3.

[0096] 2) Add 10g Ph7T7(OH)3, 100 mL triethylamine, and 250 mL tetrahydrofuran to the reactor. While stirring, add 10 mL KH106 dropwise, then reflux for 24 hours. Filter, wash repeatedly with dilute hydrochloric acid and deionized water until neutral, and dry to obtain a white powder solid: Ph7POSS-C3H6NHC6H 11 .

[0097] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor, and then add 55 g of Ph7POSS-C3H6NHC6H while stirring. 11 The reaction was carried out at room temperature for 6 hours, then 8.4 g of AEMA was added, and the reaction was continued for another 10 hours. After removing triethylamine hydrochloride and dichloromethane, a pale yellow viscous liquid was obtained: Ph7POSS-NNPP-NEMA.

[0098] Example 5

[0099] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0100] 15 parts hydroxypropyl methacrylate, 25 parts isobornyl methacrylate, 32 parts 1,10-decanediol dimethacrylate, 15 parts pentaerythritol triacrylate, 12 parts (CH3COOCH2CH2)7POSS-HNPP-NEMA, 0.6 parts azobisisobutyronitrile, 0.1 parts 2,6-dibutyl-p-cresol, and 0.3 parts isotridecyl alcohol polyoxyethylene polyoxypropylene ether.

[0101] The structural formula and preparation method of (CH3COOCH2CH2)7POSS-HNPP-NEMA are as follows:

[0102]

[0103] 1) Add 20 mL of (CH3COOCH2CH2)3SiCl3 and 50 mL of acetone solution to the reactor, and slowly add 100 mL of deionized water while stirring. Reflux for 24 hours. Filter, wash repeatedly with acetone and deionized water until neutral, and dry to obtain a pale yellow powdery solid: (CH3COOCH2CH2)7T7(OH)3.

[0104] 2) Add 10g of (CH3COOCH2CH2)7T7(OH)3, 100 mL of triethylamine, and 250 mL of tetrahydrofuran to the reactor. Add 10 mL of KH550 dropwise while stirring, and then reflux for 24 hours. Filter by suction, wash repeatedly with dilute hydrochloric acid and deionized water until neutral, and dry to obtain a white powder solid: (CH3COOCH2CH2)7POSS-C3H6NH2.

[0105] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor. While stirring, add 54 g of (CH3COOCH2CH2)7POSS-C3H6NH2 and react at room temperature for 6 hours. Then add 8.4 g of AEMA and continue the reaction for 10 hours. After removing triethylamine hydrochloride and dichloromethane, a pale yellow viscous liquid is obtained: (CH3COOCH2CH2)7POSS-HNPP-NEMA.

[0106] Example 6

[0107] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0108] 15 parts hydroxypropyl methacrylate, 25 parts isobornyl methacrylate, 33 parts 1,10-decanediol dimethacrylate, 13 parts pentaerythritol triacrylate, 13 parts [CH2=C(CH3)COOCH2CH2CH2]7POSS-HNPP-OEMA, 0.6 parts azobisisobutyronitrile, 0.1 parts 2,6-dibutyl-p-cresol, and 0.3 parts isothietrol polyoxyethylene polyoxypropylene ether.

[0109] The structural formula and preparation method of the [CH2=C(CH3)COOCH2CH2CH2]7POSS-HNPP-OEMA are as follows:

[0110]

[0111] 1) Add 20 mL of 2-methyl-2-acrylate-3-(trichlorosilyl)propyl ester and 50 mL of acetone solution to the reactor, and slowly add 100 mL of deionized water while stirring. Reflux for 24 hours. Filter by suction, wash repeatedly with acetone and deionized water until neutral, and dry to obtain a pale yellow powder solid: [CH2=C(CH3)COOCH2CH2CH2]7T7(OH)3.

[0112] 2) Add 10g of [CH2=C(CH3)COOCH2CH2CH2]7T7(OH)3, 100 mL of triethylamine, and 250 mL of tetrahydrofuran to the reactor. Add 10 mL of KH550 dropwise while stirring, then reflux for 24 hours. Filter the solution and wash repeatedly with dilute hydrochloric acid and deionized water until neutral. After drying, obtain a white powder solid: [CH2=C(CH3)COOCH2CH2CH2]7POSS-C3H6NH2.

[0113] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor. While stirring, add 68 g of [CH2=C(CH3)COOCH2CH2CH2]7POSS-C3H6NH2 and react at room temperature for 6 hours. Then add 8.3 g of 2-aminoethyl methacrylate hydrochloride and continue the reaction for 10 hours. Remove the triethylamine hydrochloride and dichloromethane to obtain a pale yellow viscous liquid: [CH2=C(CH3)COOCH2CH2CH2]7POSS-HNPP-OEMA.

[0114] Example 7

[0115] This embodiment provides a flame-retardant organic impregnating agent, prepared by mixing the following components in parts by weight at room temperature:

[0116] 30 parts hydroxyethyl methacrylate, 15 parts tridecyl methacrylate, 33 parts 1,4-butanediol diacrylate, 11 parts pentaerythritol tetraacrylate, 10 parts Me7POSS-PNPP-NPMA, 0.7 parts dimethyl azobisisobutyrate, 0.1 parts 2,6-dibutyl-p-cresol, and 0.2 parts polyethylene glycol laurate.

[0117] The structural formula and preparation method of Me7POSS-PNPP-NPMA are as follows:

[0118]

[0119] 1) The preparation of Me7T7(OH)3 is the same as in Example 1.

[0120] 2) Add 10g Me7T7(OH)3, 100 mL triethylamine and 250 mL tetrahydrofuran to the reactor, and add 10 mL dropwise while stirring. N -Phenylacetyltrimethoxysilane was then refluxed for 24 hours. The mixture was filtered, washed repeatedly with dilute hydrochloric acid and deionized water until neutral, and dried to obtain a white powder solid: Me7POSS-C3H6NHPh.

[0121] 3) Add 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine to the reactor. Add 33 g of Me7POSS-C3H6NHPh while stirring. React at room temperature for 6 hours, then add 8.9 g of APMA and continue the reaction for 10 hours. Remove triethylamine hydrochloride and dichloromethane to obtain a pale yellow viscous liquid: Me7POSS-PNPP-NPMA.

[0122] Comparative Example 1

[0123] This comparative example is based on Example 4, but lacks Ph7POSS-NNPP-NEMA. It was actually prepared by mixing the following components in parts by weight at room temperature with stirring:

[0124] 15 parts hydroxyethyl methacrylate, 37 parts isodecyl methacrylate, 35 parts 1,6-hexanediol dimethyl diacrylate, 12 parts trimethylolpropane trimethacrylate, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0125] Comparative Example 2

[0126] This comparative example provides an organic impregnating agent prepared by mixing the following components in parts by weight at room temperature with stirring:

[0127] 10 parts hydroxyethyl methacrylate, 38 parts lauryl methacrylate, 30 parts decanediol dimethacrylate, 10 parts trimethylolpropane triacrylate, 11 parts Me7POSS-NN-OEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0128] The structural formula and preparation method of Me7POSS-NN-OEMA are as follows:

[0129]

[0130] 1) Me7POSS-C3H6NHC6H 11 The preparation is the same as in Example 2.

[0131] 2) Add 200 mL of dichloromethane and 7.5 g of 2-chloroethyl methacrylate to the reactor. And 5.2g of triethylamine, and 33g of Me7POSS-C3H6NHC6H were added while stirring. 11 The reaction was carried out at room temperature for 10 hours. After removing triethylamine hydrochloride and dichloromethane, a pale yellow viscous liquid was obtained: Me7POSS-NN-OEMA.

[0132] Comparative Example 3

[0133] This comparative example provides an organic impregnating agent prepared by mixing the following components in parts by weight at room temperature with stirring:

[0134] 10 parts hydroxyethyl methacrylate, 38 parts lauryl methacrylate, 30 parts decanediol dimethacrylate, 10 parts trimethylolpropane triacrylate, 11 parts Bz-NPP-OEMA, 0.5 parts dimethyl azobisisobutyrate, 0.2 parts 2,6-dibutyl-p-cresol, and 0.3 parts polyoxyethylene sorbitan monooleate.

[0135] The structural formula and preparation method of the Bz-NPP-OEMA are as follows:

[0136]

[0137] 200 mL of dichloromethane, 10.5 g of PDCP, and 22 g of triethylamine were added to a reactor. 8.3 g of 2-aminoethyl methacrylate hydrochloride was then added with stirring. The reaction was carried out at room temperature for 6 hours, followed by the addition of 5.5 g of benzylamine, and the reaction continued for another 10 hours. After removing the triethylamine hydrochloride and dichloromethane, a pale yellow solid, Bz-NPP-OEMA, was obtained.

[0138] The following performance tests were conducted on Examples 1-4 and Comparative Examples 1-2, and the results are shown in Table 1.

[0139] 1) Viscosity: Tested according to GB / T2794-2013 Adhesives Viscosity Determination Single Cylindrical Rotation Viscometer Method.

[0140] 2) Volume shrinkage rate: The shrinkage rate was determined by hydrometer method and water displacement method respectively. The density of the adhesive before curing is ra, and the density of the adhesive stick after curing is rc. Then: shrinkage rate = (rc-ra) / rc.

[0141] 3) Limiting Oxygen Index (LOI): Determined according to GB / T 10707-2008 (Oxygen Index Tester Combustion Test Method).

[0142] 4) High-temperature sealing performance at 204℃: The test sample is impregnated with the organic impregnating agent specified in MIL-I-17563C using a special impregnation test ring. After curing, it is placed in a constant temperature aging chamber at 204℃ for 42 days. After the aging period, it is taken out, cooled to room temperature, and then the sealing performance is tested using the sealing performance test device specified in MIL-I-17563C. If there is no leakage, it indicates that the test sample has good high-temperature resistance at 204℃; otherwise, the high-temperature resistance at 204℃ is poor.

[0143] Table 1 Performance Comparison of Examples and Comparative Examples

[0144]

[0145] In Examples 1-7, adding only a small amount of silicon-phosphorus-nitrogen synergistic flame retardant can impart excellent flame retardant effect to the impregnating agent, while maintaining the viscosity, curing hardness, volume shrinkage, and high-temperature sealing performance of the impregnating agent. Therefore, the acrylate impregnating agent of the present invention has ideal flame retardant performance and superior flame retardant stability. The flame retardant in Comparative Example 2 is a reactive monomer of acrylate containing nano-Me7POSS, therefore the thermosetting material of the impregnating agent has high hardness, low volume shrinkage, and high-temperature sealing performance.

[0146] Comparative Example 1 is based on the formulation of Example 4, but lacks a flame retardant. Therefore, the impregnating agent does not have a flame retardant effect and is a flammable material.

[0147] In Comparative Examples 2 and 3, the flame retardants were silicon-based and phosphorus-nitrogen-based flame retardants, respectively. However, the flame retardant effect imparted to the impregnating agent by the two was not ideal, so the impregnating agent was still considered a combustible material.

[0148] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A flame-retardant organic impregnating agent, characterized in that, The flame-retardant organic impregnating agent comprises the following components in parts by weight: 40-50 parts of monofunctional acrylate monomer, 25-35 parts of difunctional acrylate monomer, 10-15 parts of polyfunctional acrylate monomer, 10-15 parts of POSS-NPP-EMA flame retardant, 0.05-0.5 parts of surfactant, 0.1-0.2 parts of polymerization inhibitor, and 0.3-0.8 parts of initiator; The structural formula of the POSS-NPP-EMA flame retardant is as follows: In the formula, R is selected from C1 to C10 alkyl, phenyl or acetoxyethyl; Y is selected from H, alkyl or phenyl groups from C1 to C10; Z is either O or NH; n is 1 or 2.

2. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The R is selected from C1 to C6 alkyl, phenyl, or acetoxyethyl; The Y is selected from H, C1 to C6 alkyl or phenyl groups.

3. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The structural formula of the POSS-NPP-EMA flame retardant is selected from any of the following: 、 、 、 、 、 。 4. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The monofunctional acrylate monomer is selected from at least one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, octyl methacrylate, decyl methacrylate, isodecyl methacrylate, isobornyl methacrylate, lauryl methacrylate, diethylene glycol ethyl ether methacrylate, tridecanol methacrylate, tetradecanol methacrylate, and octadecyl methacrylate.

5. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The bifunctional acrylate is selected from at least one of dimethyl acrylate, ethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethyl diacrylate, 1,10-decanediol dimethacrylate, triethylene glycol dimethacrylate, and tripropylene glycol diacrylate.

6. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The multifunctional acrylate is selected from at least one of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate.

7. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The initiator is selected from at least one of lauroyl peroxide, diisopropylbenzene peroxide, tert-butyl peroxide, azobisisobutyronitrile, azobisisoheptanenitrile, and dimethyl azobisisobutyronitrile.

8. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The polymerization inhibitor is selected from at least one of hydroquinone, benzoquinone, anthraquinone, 1,4-naphthoquinone, tert-butylcatechol, and 2,6-dibutyl-p-cresol.

9. The flame-retardant organic impregnating agent according to claim 1, characterized in that, The surfactant is selected from at least one of polyoxyethylene sorbitan monooleate, polyoxyethylene hexadecyl ether, isotridecyl polyoxyethylene polyoxypropylene ether, fatty acid polyoxyethylene ester or polyethylene glycol laurate, and polyoxyethylene castor oil.

10. A method for preparing a flame-retardant organic impregnating agent according to any one of claims 1-9, characterized in that, The preparation method includes the following steps: The monofunctional acrylate monomer, difunctional acrylate monomer, polyfunctional acrylate monomer, POSS-NPP-EMA flame retardant, surfactant, polymerization inhibitor, and initiator are stirred and mixed evenly at room temperature to obtain the flame-retardant organic impregnating agent.

11. The preparation method according to claim 10, characterized in that, The POSS-NPP-EMA flame retardant is prepared by the following steps: 1) RSiCl3, acetone and water react to obtain R7T7(OH)3; 2) Under the action of triethylamine, R7T7(OH)3 reacts with silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 to obtain R7POSS-NHY; X is -CH2CH2CH2NHY; 3) Under the action of triethylamine, R7POSS-NHY reacts with phenyl dichlorophosphate, and then reacts with amino-substituted methacrylate / amide to obtain the POSS-NPP-EMA flame retardant.

12. The preparation method according to claim 11, characterized in that, The RSiCl3 is selected from methyltrichlorosilane, ethyltrichlorosilane, cyclohexyltrichlorosilane, phenyltrichlorosilane, or acetoxyethyltrichlorosilane.

13. The preparation method according to claim 11, characterized in that, The silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is selected from γ-aminopropyltriethoxysilane, 3-(methylamino)propyltrimethoxysilane, 3-( N -cyclohexylaminopropyltrimethoxysilane, N -Phenylacetyl-3-aminopropyltrimethoxysilane or N - n-Butyl-3-aminopropyltriethoxysilane.

14. The preparation method according to claim 11, characterized in that, The amino-substituted methacrylate / amide is selected from 2-aminoethyl methacrylate hydrochloride, 2-(tert-butylamino)ethyl methacrylate, N -(2-aminoethyl)methacrylamide hydrochloride or N -(3-aminopropyl)methacrylamide hydrochloride.

15. The preparation method according to claim 11, characterized in that, In step 1), RSiCl3 and acetone are mixed, and deionized water is slowly added while stirring. The mixture is then refluxed to carry out the reaction. After the reaction is complete, the solid is separated, washed with acetone and deionized water until neutral, and dried to obtain R7T7(OH)3.

16. The preparation method according to claim 11, characterized in that, In step 2), R7T7(OH)3 and triethylamine are added to tetrahydrofuran, and the silane coupling agent XSi(OCH3)3 or XSi(OC2H5)3 is added dropwise under stirring. The mixture is then refluxed to carry out the reaction. After the reaction is completed, the solid is separated, washed with dilute hydrochloric acid and deionized water until neutral, and dried to obtain R7POSS-NHY.

17. The preparation method according to claim 11, characterized in that, In step 3), phenyl dichlorophosphate and triethylamine are added to dichloromethane, and R7POSS-NHY is added under stirring. The reaction is carried out at room temperature. After the reaction is completed, amino-substituted methacrylate / amide is added to continue the reaction. After the reaction is completed, triethylamine hydrochloride and dichloromethane are removed to obtain the POSS-NPP-EMA flame retardant.

18. The preparation method according to claim 11 or 17, characterized in that, In step 3), the molar ratio of triethylamine, phenyl dichlorophosphate, R7POSS-NHY, and amino-substituted methacrylate / amide is (2.1~3.2):1:1:1.

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