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CN-121975485-A - Flame-retardant silicone sealant and preparation method thereof

CN121975485ACN 121975485 ACN121975485 ACN 121975485ACN-121975485-A

Abstract

The application provides a flame-retardant silicone sealant and a preparation method thereof, wherein the flame-retardant silicone sealant comprises, by mass, 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 20-40 parts of hydrophobically modified fumed silica, 5-20 parts of modified cross-linking agent material, 10-30 parts of melamine polyphosphate and 0.1 part of catalyst, and the modified cross-linking agent material is prepared by modifying gamma- (2, 3-epoxypropoxy) propyl trimethoxysilane with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. The application improves the flame retardant property and the mildew resistance of the silicone sealant.

Inventors

  • ZHANG XIANCHENG
  • WU HONGBO
  • Jiang Baozeng
  • Fang Xumei
  • WEI LIN
  • HE SHENGYIN

Assignees

  • 湖北君邦新材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260401

Claims (10)

  1. 1. The flame-retardant silicone sealant is characterized by comprising the following raw materials in parts by mass: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 20-40 parts of hydrophobically modified fumed silica, 5-20 parts of modified cross-linking agent material, 10-30 parts of melamine polyphosphate and 0.1 part of catalyst; The modified cross-linking agent material is prepared by modifying gamma- (2, 3-glycidoxy) propyl trimethoxy silane by 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.
  2. 2. The flame retardant silicone sealant of claim 1, wherein the modified cross-linker material is further loaded with zinc pyrithione.
  3. 3. The flame retardant silicone sealant according to claim 1, wherein the preparation method of the modified cross-linking agent material comprises the following steps: Adding DOPO, gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane and azodiisobutyronitrile into anhydrous toluene, and enabling P-H in DOPO molecules and epoxy groups of gamma- (2, 3-epoxypropoxy) propyl trimethoxy silane to undergo an addition reaction to obtain the DOPO-GPTMS material serving as a modified cross-linking agent material.
  4. 4. The flame retardant silicone sealant according to claim 3, wherein the method of preparing the modified cross-linker material further comprises the steps of: Adding DOPO-GPTMS material and ZPT into absolute ethyl alcohol to load the ZPT to obtain the ZPT/DOPO-GPTMS material as modified cross-linking agent material.
  5. 5. The flame retardant silicone sealant according to claim 4, wherein the preparation method of the modified cross-linker material comprises the following steps: Adding 20 parts of DOPO, 10-15 parts of gamma- (2, 3-glycidoxy) propyl trimethoxy silane and 0.5-1 part of azodiisobutyronitrile into 300-600 parts of anhydrous toluene, and stirring and reacting for 4-8 hours at 80-120 ℃ under the protection of nitrogen to obtain a DOPO-GPTMS material; Dispersing 20 parts of DOPO-GPTMS material and 5-10 parts of ZPT in 200-400 parts of absolute ethyl alcohol, stirring and loading at 40-60 ℃ for 2-5 hours to load the ZPT on the material, and drying the material at 50 ℃ for 6-12 hours under a vacuum condition after the reaction is finished to obtain the ZPT/DOPO-GPTMS material serving as a modified cross-linking agent material.
  6. 6. A flame retardant silicone sealant according to claim 1, wherein the catalyst comprises dibutyl tin dilaurate.
  7. 7. The flame retardant silicone sealant according to claim 1, wherein the alpha, omega-dihydroxy polydimethylsiloxane has a number average molecular weight of 2000-5000.
  8. 8. The flame retardant silicone sealant according to claim 1, wherein the hydrophobically modified fumed silica is fumed silica hydrophobically modified with hexamethyldisilazane.
  9. 9. The flame retardant silicone sealant according to claim 8, wherein the hydrophobically modified fumed silica is hydrophobically modified with hexamethyldisilazane comprising the steps of: and mixing the fumed silica and hexamethyldisilazane, and enabling silanol groups on the surface of the fumed silica to react with the hexamethyldisilazane, wherein the silanol groups on the surface of the fumed silica are blocked by trimethylsilyl groups, so that the hydrophobically modified fumed silica is obtained.
  10. 10. The preparation method of the flame-retardant silicone sealant is characterized by comprising the following steps: Providing the raw material of the flame-retardant silicone sealant according to any one of claims 1-9; adding the raw materials into a stirring kettle for reaction to obtain single-component flame-retardant silicone sealant; and (5) filling is completed in an anhydrous environment, and a finished flame-retardant silicone sealant product is obtained.

Description

Flame-retardant silicone sealant and preparation method thereof Technical Field The application relates to the technical field of silicone sealants, in particular to a flame-retardant silicone sealant and a preparation method thereof. Background The silicone sealant is a paste which is prepared by mixing polydimethylsiloxane serving as a main raw material, a cross-linking agent, a filler, a plasticizer, a coupling agent and a catalyst in a vacuum state, and is cured to form the elastic silicone rubber by reacting with water in the air at room temperature. One-component silicone sealants are ointment-like materials that cure to a tough, rubbery solid upon exposure to moisture in the air. The silicone glass adhesive has strong adhesive force and high tensile strength, and simultaneously has the characteristics of weather resistance, vibration resistance, moisture resistance, odor resistance and large adaptation to cold and hot changes. In addition, the adhesive has wider applicability and can realize the adhesion among most building material products, so the application value is very high. In recent years, as fire in high-rise buildings frequently occurs, people's fire protection awareness is gradually increasing. The sealant applied to fireproof blocking of high-rise buildings must have flame retardant property. The silicone sealant used on the curtain wall most has excellent ageing resistance and mechanical properties, but can burn at 200-300 ℃ and belongs to combustible materials, and the silicone sealant capable of effectively resisting flame is more and more important for reducing the fire risk of buildings. Therefore, how to realize the flame retardant effect while guaranteeing the performance of the silicone sealant is a technical problem to be solved in the field. Disclosure of Invention The application provides a flame-retardant silicone sealant and a preparation method thereof, wherein the flame-retardant silicone sealant uses a product modified by gamma- (2, 3-glycidoxy) propyl trimethoxysilane through 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as a cross-linking agent, and the flame-retardant silicone sealant is matched with melamine polyphosphate, so that the flame retardance of the silicone sealant is better improved. The application provides a flame-retardant silicone sealant which comprises, by mass, 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 20-40 parts of hydrophobically modified fumed silica, 5-20 parts of a modified cross-linking agent material, 10-30 parts of melamine polyphosphate and 0.1 part of a catalyst, wherein the modified cross-linking agent material is prepared by modifying gamma- (2, 3-epoxypropoxy) propyl trimethoxysilane with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. According to the flame-retardant silicone sealant, alpha, omega-dihydroxypolydimethylsiloxane is used as a main material, nanoscale particles and high specific surface area of hydrophobic modified fumed silica enable the flame-retardant silicone sealant to form a three-dimensional network structure in a silicone matrix, the three-dimensional network structure is achieved through interaction of intermolecular force and an organic matrix, the network structure can limit movement of polymer chains, viscosity is improved, sedimentation and sagging are prevented, construction manufacturability is improved, ‌ is achieved, meanwhile, surface polarity is reduced through hydrophobic modification, compatibility of a nonpolar silicone matrix is enhanced, moisture absorption clusters are reduced, storage stability is improved, melamine polyphosphate (MPP) is used as a flame retardant, inert gas is decomposed and released at high temperature and is promoted to form a heat-insulating flame-retardant layer, flame retardant performance of the material is remarkably improved and dripping is restrained, the modified cross-linking agent material is gamma- (2, 3-epoxypropoxy) propyltrimethoxysilane (GPTMS) which is modified by 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), si (OR) 3) is arranged on a molecular chain, si (O) is arranged on the molecular chain, the Si (O) is hydrolyzed, the Si (PDMS) can be condensed with a hydrolytic catalyst, the hydroxyl groups can not be condensed with the silicon catalyst, the three-dimensional network is not generated, the flame-retardant is enabled to take place, and the flame-retardant is not to be converted into a three-dimensional cross-retardant structure, the flame-retardant structure is formed, and the flame-retardant structure is not compatible with the three-dimensional phase-retardant structure is simultaneously, and the flame-retardant structure is formed. Specifically, in the combustion process of the silicone sealant, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide connected in a molecular chain releases phosphorus-containing free radicals in a gas phase in the early stage of combustion to quench H, OH and inhibit flame propagation,