A low-temperature toughening and flame-retardant organosilicon sulfonate, a preparation method and application thereof

Abstract

The present application relates to the technical field of synthetic silicone sulfonate, the preparation method of the silicone sulfonate with low-temperature toughening and flame retardation, which adopts one-pot preparation technology, introduces sulfonate groups and uses surface coating modification technology of core-shell structure to solve the problems of stability, compatibility and hygroscopicity of traditional flame retardants. Specifically, polysiloxane is used as the inner core carrier, the sulfonate groups are bonded to the polysiloxane through the thiol functional group of the silicon and the thiol-ene click chemistry reaction, and the sulfonate groups are introduced into the side chain. The sulfonate groups in the inner core can effectively avoid the problem of small molecule sulfonate precipitation, thereby ensuring the stability during use. Under the action of the initiator and the crosslinking agent, the sulfonate groups are grafted to the silicone inner core to coat the soft monomer and the hard monomer polymer, and the formed core-shell structure not only has the flame retardation effect, but also has the low-temperature toughening effect.

Description

Technical Field

[0001] This invention relates to the field of synthetic organosilicon sulfonate technology, specifically to an organosilicon sulfonate that combines low-temperature toughening and flame retardancy, its preparation method, and its applications. Background Technology

[0002] Organosiloxanes have gained widespread application in many industrial fields due to their superior properties, especially in high-temperature resistance, resistance to oxidative degradation, and environmental friendliness. These properties make them key materials in high-performance plastics additives, insulating materials in the microelectronics industry, and flame retardants. In recent years, the application of siloxanes in the field of flame retardants has received increasing attention, particularly in the flame-retardant modification of polycarbonate (PC) materials, where they have demonstrated unique advantages.

[0003] Existing sulfonate flame retardants, such as KSS, have certain limitations in their application as small molecules in PC matrices. Due to their small molecular size, their physical entanglement with the PC matrix is ​​weak, making them prone to precipitation, which leads to a decrease in flame retardant effect over long-term use. Therefore, the effect of using small molecule sulfonates alone as flame retardants is limited, and their application range is relatively narrow.

[0004] Although existing technologies have shell structures that use sulfonates and monomers grafted onto the surface of an organosilicon core as flame retardants, the sulfonates are still exposed, which makes them more prone to moisture absorption and has insufficient compatibility with resins. This has an adverse effect on flame retardancy and low-temperature toughening, making them unsuitable for use as flame-retardant low-temperature toughening agents. Summary of the Invention

[0005] To overcome the shortcomings and deficiencies of existing technologies, one objective of this invention is to provide a method for preparing organosilicon sulfonates that combine low-temperature toughening and flame retardancy. This method employs a one-pot preparation technique, addressing the stability, compatibility, and hygroscopicity issues of traditional flame retardants by introducing sulfonate groups and utilizing a core-shell structure surface coating modification technique. Specifically, polysiloxane is used as the core carrier. Sulfonate groups are introduced into the side chains of the sulfonate group via a click chemical reaction using silicon with thiol functional groups. The sulfonate group within the core effectively prevents the precipitation of small molecule sulfonates, thus ensuring its stability during use. Under the action of an initiator and crosslinking agent, the sulfonate is grafted onto the organosilicon core, coating soft and hard monomer polymers. The resulting core-shell structure not only improves compatibility with different substrates but also effectively solves the hygroscopic and hydrophilic problems of sulfonates while maintaining their flame-retardant activity, thereby improving flame-retardant efficiency. This preparation method is simple to operate, easy to control, has high production efficiency, and low production cost, making it suitable for large-scale production.

[0006] The second objective of this invention is to provide an organosilicon sulfonate that combines low-temperature toughening and flame retardancy. It uses organosilicon grafted with sulfonate as the core and soft monomers and hard monomers as the shell to encapsulate the sulfonate inside, thereby reducing the water absorption of the organosilicon sulfonate and improving the compatibility between the organosilicon sulfonate and the resin. It not only has flame retardant effect but also low-temperature toughening effect.

[0007] The third objective of this invention is to provide an application of organosilicon sulfonates that combine low-temperature toughening and flame retardancy. The coating layer of organosilicon sulfonates can provide additional physical protection for sulfonate-containing polysiloxanes, reducing direct contact with the external environment, thereby greatly improving their dispersibility in PC resin materials. Furthermore, the core-shell structure of organosilicon sulfonates has a multi-layered structure and a soft monomer polymer layer with a low glass transition temperature. The resulting organosilicon sulfonates have excellent weather resistance and low-temperature performance, and can also enhance the low-temperature toughening effect on polycarbonate (PC) materials, which is particularly important for improving their performance in low-temperature environments.

[0008] One of the objectives of this invention is achieved through the following technical solution: a method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy, comprising the following steps:

[0009] (S1) Take organosilicon DMC and mercaptosilane coupling agent, mix them, and then use a homogenizer to perform high-speed shearing at a speed of 4000-10000 rpm for 5-30 min to obtain organosilicon mixture.

[0010] (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 80-100°C for 5-10 hours to obtain an organopolysiloxane core emulsion.

[0011] (S3) Adjust the pH of the organopolysiloxane core emulsion to the range of 9-12, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir the reaction at 50-90℃ and under UV light with a wavelength of 365nm for 5-10h to obtain sulfonate-grafted organosilicon core emulsion.

[0012] (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, and continue to stir and react at 50-90°C for 5-10 h. Then add hard monomer and continue to stir and react at 50-90°C for 5-10 h to obtain a polymer emulsion with a core-shell structure.

[0013] (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained.

[0014] Preferably, in step (S1), the organosilicon DMC is at least one selected from hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecylcyclohexasiloxane (D6), and the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane and / or 3-mercaptopropyltrimethoxysilane; wherein the mercaptosilane coupling agent accounts for 10%-50% of the molar percentage of the organosilicon mixture.

[0015] Preferably, in step (S2), the catalyst is an acidic catalyst, and the emulsifier is at least one of cationic surfactant, anionic surfactant, and nonionic surfactant; wherein the total mass of the organosilicon mixture accounts for 20%-40% of the mass of the aqueous phase, the amount of the catalyst is 1%-5% of the mass of the organosilicon mixture, and the amount of the emulsifier is 1%-20% of the mass of the organosilicon mixture.

[0016] Furthermore, the catalyst includes at least one of alkyl sulfonic acid catalysts, aryl sulfonic acid catalysts, inorganic acid catalysts, and other organic acid catalysts. Alkyl sulfonic acid catalysts include at least one of methanesulfonic acid, trifluoromethanesulfonic acid, ethyl sulfonic acid, hydroxyethyl sulfonic acid, propyl sulfonic acid, and 1-butyl sulfonic acid. Aryl sulfonic acid catalysts include at least one of benzenesulfonic acid, methylbenzenesulfonic acid, dimethylbenzenesulfonic acid, ethylbenzenesulfonic acid, diethylbenzenesulfonic acid, and dodecylbenzenesulfonic acid. Inorganic acid catalysts include at least one of hydrochloric acid, sulfuric acid, nitric acid, carbonic acid, and phosphoric acid. Other organic acid catalysts include at least one of formic acid, acetic acid, glycolic acid, lactic acid, and malonic acid.

[0017] Furthermore, cationic surfactants include at least one of alkyl trimethyl quaternary ammonium salts, dialkyl dimethyl quaternary ammonium salts, benzyl alkyl dimethyl quaternary ammonium salts, monoalkyl quaternary ammonium salts, alkylphenol polyoxyethylene quaternary ammonium salts, N-alkyl diethanolamine salts, pyridinium salts, imidazolines, and morpholines. Anionic surfactants include at least one of alkyl sulfates, alkylbenzene sulfonates, fatty acid salts, alkyl hydrogen sulfates, N-acyl taurine, alkylbenzene sulfonates, alkyl naphthalene sulfonates, alkyl diphenyl ether disulfonates, dialkyl sulfosuccinates, monoalkyl sulfosuccinates, N-acyl amino acid salts, and alkyl phosphates. Nonionic surfactants include at least one of glyceryl monostearate, sorbitol fatty acid esters, glyceryl fatty acid esters, polyglycerol fatty acid esters, and propylene glycol fatty acid esters.

[0018] Preferably, in step (S3), the p-styrene sulfonate is potassium p-styrene sulfonate and / or sodium p-styrene sulfonate; wherein the p-styrene sulfonate accounts for 10%-80% of the total mercaptosilane coupling agent in molar percentage, and the amount of 1-hydroxycyclohexylphenyl ketone is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

[0019] Preferably, in step (S4), the soft monomer is at least one of 2-ethylhexyl acrylate, butyl acrylate, and lauryl methacrylate; the hard monomer is at least one of acrylic acid, methacrylic acid, methyl methacrylate, isobornyl methacrylate, styrene, methylstyrene, acrylonitrile, acrylamide, and N-hydroxymethylacrylamide; and the initiator is at least one of organic peroxide initiator, inorganic peroxide initiator, azo initiator, or redox initiator.

[0020] Using the above technical solution, the soft monomer has a low glass transition temperature, excellent weather resistance, and excellent low-temperature performance, playing an important role in low-temperature toughening; the hard monomer has a high glass transition temperature, providing sufficient cohesive strength, improving tensile strength, and exhibiting good chemical and dimensional stability. Further, the organic peroxide initiator includes at least one of benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, tert-butyl peroxide, tert-butyl benzoate, tert-butyl valerate peroxide, methyl ethyl ketone peroxide, cyclohexanone peroxide, diisopropyl peroxide, and dicyclohexyl peroxide. The inorganic peroxide initiator includes at least one of potassium persulfate, sodium persulfate, and ammonium persulfate. The azo initiator includes at least one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, and 2,2'-azobis(2,4-dimethylpentanonitrile). Redox initiators include at least one of benzoyl peroxide / sucrose, tert-butyl hydroperoxide / sodium thiosulfate, tert-butyl hydroperoxide / sodium metabisulfite, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydroperoxide / tartaric acid, hydroperoxide / sodium thiosulfate, ammonium persulfate / ferrous sulfate, hydroperoxide / ferrous sulfate, benzoyl peroxide / N,N-dimethylaniline, benzoyl peroxide / N,N-diethylaniline, benzoyl peroxide / ferrous pyrophosphate, potassium persulfate / silver nitrate, persulfate / thiol, cumene hydroperoxide / ferrous chloride, potassium persulfate / ferrous chloride, hydroperoxide / ferrous chloride, and cumene hydroperoxide / tetraethyleneimine.

[0021] Preferably, in step (S4), the crosslinking agent is at least one selected from allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, allyl maleate, diallyl fumarate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, diallylamine, triallylamine, divinylbenzene, trivinylbenzene, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, and trimethylolmethane trimethacrylate.

[0022] Preferably, in step (S4), the amount of the soft monomer is 5%-15% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.1%-1% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 25%-45% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

[0023] Preferably, in step (S5), the demulsifier is a metal salt solution and / or a water-soluble organic solvent; the amount of the demulsifier is 0.5-3 times the mass of the polymer emulsion with a core-shell structure.

[0024] Furthermore, the metal salt solution includes at least one of potassium chloride, sodium chloride, ammonium chloride, calcium chloride, magnesium chloride, potassium acetate, sodium acetate, ammonium acetate, magnesium acetate, calcium acetate, potassium sulfate, sodium sulfate, ammonium sulfate, calcium sulfate, and magnesium sulfate. The water-soluble organic solvent includes at least one of methanol, ethanol, acetic acid, and acetone.

[0025] The second objective of this invention is achieved through the following technical solution: an organosilicone sulfonate that combines low-temperature toughening and flame retardancy is prepared by the organosilicone sulfonate preparation method described above.

[0026] The third objective of this invention is achieved through the following technical solution: the application of the above-mentioned organosilicon sulfonate that combines low-temperature toughening and flame retardancy, wherein the organosilicon sulfonate that combines low-temperature toughening and flame retardancy is used for low-temperature toughening and flame retardant modification of polycarbonate.

[0027] The beneficial effects of this invention are as follows: This invention provides a method for preparing organosilicon sulfonates that combine low-temperature toughening and flame retardancy. It employs a one-pot synthesis technique for high efficiency. By introducing sulfonate groups and utilizing core-shell structure surface coating modification technology, it improves compatibility, reduces the hygroscopicity of sulfonate groups, and enhances flame retardant efficiency, thus solving problems related to stability, compatibility, and hygroscopicity in traditional flame retardants. Specifically, it uses polysiloxane as the core carrier, and leverages the silicon with thiol functional groups to attach sulfonate groups via click chemical reactions in thiol olefins, introducing the sulfonate groups into its side chains. The presence of sulfonates within the core effectively avoids the precipitation of small molecule sulfonates, thereby ensuring its stability during use. The core-shell structure formed by grafting organosilicon cores with sulfonates under the action of initiators and crosslinking agents not only improves compatibility with different substrates, but also effectively solves the problems of hygroscopicity and hydrophilicity of sulfonates, while maintaining the flame retardant activity of sulfonates, thereby improving flame retardant efficiency. This preparation method is simple to operate, easy to control, has high production efficiency and low production cost, and can be used for large-scale production.

[0028] The present invention relates to an organosilicon sulfonate that combines low-temperature toughening and flame retardancy. It has a sulfonate-grafted organosilicon core and a shell structure composed of acrylate soft monomers and hard monomers polymerized sequentially from the inside to the outside. The soft monomer polymer layer has a low glass transition temperature, resulting in organosilicon sulfonate with excellent weather resistance and low-temperature performance. It can also enhance the low-temperature toughening effect on polycarbonate (PC) materials and is a low-temperature toughening agent that can be used for low-temperature toughening and flame retardant modification of PC resin. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the synthesis mechanism of the present invention. Detailed Implementation

[0030] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0031] Example 1

[0032] A method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy includes the following steps:

[0033] (S1) After mixing organosilicon DMC and mercaptosilane coupling agent, the mixture is subjected to high-speed shearing at a speed of 8000 rpm for 15 min using a homogenizer to obtain organosilicon mixture.

[0034] (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 90°C for 7 hours to obtain an organopolysiloxane core emulsion.

[0035] (S3) Adjust the pH of the organopolysiloxane core emulsion to 9, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir the reaction at 80°C and under UV light irradiation at a wavelength of 365nm for 7h to obtain sulfonate-grafted organosilicon core emulsion.

[0036] (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, and continue to stir and react at 80°C for 7 hours. Then add hard monomer and continue to stir and react at 80°C for 7 hours to obtain a polymer emulsion with a core-shell structure.

[0037] (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained.

[0038] In step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane; wherein the mercaptosilane coupling agent accounts for 20% of the molar percentage of the organosilicon mixture.

[0039] In step (S2), the total mass of the organosilicon mixture accounts for 30% of the mass of the aqueous phase, the amount of the catalyst is 1% of the mass of the organosilicon mixture, the amount of the emulsifier is 4% of the mass of the organosilicon mixture, and the catalyst is methanesulfonic acid. The emulsifier is a mixture of sodium dodecylbenzenesulfonate and dehydrated sorbitol fatty acid ester in a weight ratio of 4:1.

[0040] In step (S3), the p-styrene sulfonate is sodium p-styrene sulfonate; wherein the p-styrene sulfonate accounts for 50% of the total mercaptosilane coupling agent in molar percentage, and the amount of 1-hydroxycyclohexylphenyl ketone is 0.5% of the mass of the organopolysiloxane core emulsion.

[0041] In step (S4), the soft monomer is butyl acrylate, the hard monomer is acrylic acid, and the initiator is benzoyl peroxide.

[0042] In step (S4), the crosslinking agent is allyl methacrylate.

[0043] In step (S4), the amount of the soft monomer is 10% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.5% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 30% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 0.5% of the mass of the organopolysiloxane core emulsion.

[0044] In step (S5), the demulsifier is calcium chloride; the amount of the demulsifier is 0.5 times the mass of the polymer emulsion with a core-shell structure.

[0045] Example 2

[0046] A method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy includes the following steps:

[0047] (S1) After mixing organosilicon DMC and mercaptosilane coupling agent, the mixture is subjected to high-speed shearing at a speed of 8000 rpm for 5 minutes using a homogenizer to obtain organosilicon mixture.

[0048] (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 80°C for 6 hours to obtain an organopolysiloxane core emulsion;

[0049] (S3) Adjust the pH of the organopolysiloxane core emulsion to 9, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir the reaction at 60°C and under UV light irradiation at a wavelength of 365nm for 6 hours to obtain sulfonate-grafted organosilicon core emulsion.

[0050] (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, and continue to stir and react at 60°C for 6 hours. Then add hard monomer and continue to stir and react at 60°C for 6 hours to obtain a polymer emulsion with a core-shell structure.

[0051] (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained.

[0052] In step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane; wherein the mercaptosilane coupling agent accounts for 20% of the molar percentage of the organosilicon mixture.

[0053] In step (S2), the total mass of the organosilicon mixture accounts for 20% of the mass of the aqueous phase, the amount of the catalyst is 1% of the mass of the organosilicon mixture, the amount of the emulsifier is 2% of the mass of the organosilicon mixture, and the catalyst is methanesulfonic acid. The emulsifier is a mixture of sodium dodecylbenzenesulfonate and dehydrated sorbitol fatty acid ester in a weight ratio of 2:1.

[0054] In step (S3), the p-styrene sulfonate is sodium p-styrene sulfonate; wherein the p-styrene sulfonate accounts for 20% of the total mercaptosilane coupling agent in molar percentage, and the amount of 1-hydroxycyclohexylphenyl ketone is 0.2% of the mass of the organopolysiloxane core emulsion.

[0055] In step (S4), the soft monomer is butyl acrylate, the hard monomer is methacrylic acid, and the initiator is benzoyl peroxide.

[0056] In step (S4), the crosslinking agent is allyl methacrylate.

[0057] In step (S4), the amount of the soft monomer is 5% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.2% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 28% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 0.2% of the mass of the organopolysiloxane core emulsion.

[0058] In step (S5), the demulsifier is calcium chloride; the amount of the demulsifier is 0.5 times the mass of the polymer emulsion with a core-shell structure.

[0059] Example 3

[0060] A method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy includes the following steps:

[0061] (S1) After mixing organosilicon DMC and mercaptosilane coupling agent, the mixture is subjected to high-speed shearing at 8000 rpm for 30 min using a homogenizer to obtain organosilicon mixture.

[0062] (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 95°C for 9 hours to obtain an organopolysiloxane core emulsion;

[0063] (S3) Adjust the pH of the organopolysiloxane core emulsion to 9, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir and react for 9 h at 85 °C and under UV light with a wavelength of 365 nm to obtain sulfonate-grafted organosilicon core emulsion.

[0064] (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, and continue to stir and react at 85°C for 9 hours. Then add hard monomer and continue to stir and react at 85°C for 9 hours to obtain a polymer emulsion with a core-shell structure.

[0065] (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained.

[0066] In step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercaptosilane coupling agent is a mixture of 3-mercaptopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane in a weight ratio of 2:1; wherein the mercaptosilane coupling agent accounts for 40% of the molar percentage of the organosilicon mixture.

[0067] In step (S2), the total mass of the organosilicon mixture accounts for 40% of the mass of the aqueous phase, the amount of the catalyst is 3% of the mass of the organosilicon mixture, the amount of the emulsifier is 8% of the mass of the organosilicon mixture, and the catalyst is methanesulfonic acid. The emulsifier is a mixture of sodium dodecylbenzenesulfonate and dehydrated sorbitol fatty acid ester in a weight ratio of 5:1.

[0068] In step (S3), the p-styrene sulfonate is a mixture of potassium p-styrene sulfonate and sodium p-styrene sulfonate in a ratio of 1:5; wherein the p-styrene sulfonate accounts for 50% of the total mercaptosilane coupling agent, and the amount of 1-hydroxycyclohexylphenyl ketone is 1% of the mass of the organopolysiloxane core emulsion.

[0069] In step (S4), the soft monomer is butyl acrylate, the hard monomer is acrylic acid or methacrylic acid, and the initiator is benzoyl peroxide.

[0070] In step (S4), the crosslinking agent is allyl methacrylate.

[0071] In step (S4), the amount of the soft monomer is 15% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.8% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 40% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 1% of the mass of the organopolysiloxane core emulsion.

[0072] In step (S5), the demulsifier is calcium chloride; the amount of the demulsifier is 0.5 times the mass of the polymer emulsion with a core-shell structure.

[0073] Example 4

[0074] A method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy includes the following steps:

[0075] (S1) After mixing organosilicon DMC and mercaptosilane coupling agent, the mixture is subjected to high-speed shearing at a speed of 8000 rpm for 20 min using a homogenizer to obtain organosilicon mixture.

[0076] (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 80°C for 8 hours to obtain an organopolysiloxane core emulsion.

[0077] (S3) Adjust the pH of the organopolysiloxane core emulsion to 9, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir and react for 8 hours at 80°C and under UV light with a wavelength of 365nm to obtain sulfonate-grafted organosilicon core emulsion.

[0078] (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, continue to stir and react at 80°C for 8 hours, then add hard monomer, continue to stir and react at 80°C for 8 hours to obtain a polymer emulsion with a core-shell structure.

[0079] (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained.

[0080] In step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane; wherein the mercaptosilane coupling agent accounts for 30% of the molar percentage of the organosilicon mixture.

[0081] In step (S2), the total mass of the organosilicon mixture accounts for 30% of the mass of the aqueous phase, the amount of the catalyst is 3% of the mass of the organosilicon mixture, the amount of the emulsifier is 3% of the mass of the organosilicon mixture, and the catalyst is methanesulfonic acid. The emulsifier is a mixture of sodium dodecylbenzenesulfonate and dehydrated sorbitol fatty acid ester in a weight ratio of 4:1.

[0082] In step (S3), the p-styrene sulfonate is sodium p-styrene sulfonate; wherein the p-styrene sulfonate accounts for 40% of the total mercaptosilane coupling agent in molar percentage, and the amount of 1-hydroxycyclohexylphenyl ketone is 0.8% of the mass of the organopolysiloxane core emulsion.

[0083] In step (S4), the soft monomer is butyl acrylate, the hard monomer is acrylic acid or methacrylic acid, and the initiator is benzoyl peroxide.

[0084] In step (S4), the crosslinking agent is allyl methacrylate.

[0085] In step (S4), the amount of the soft monomer is 8% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.8% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 32% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 0.8% of the mass of the organopolysiloxane core emulsion.

[0086] In step (S5), the demulsifier is calcium chloride; the amount of the demulsifier is 0.5 times the mass of the polymer emulsion with a core-shell structure.

[0087] Comparative Example 1

[0088] The difference between this comparative example and Example 1 is as follows:

[0089] In step (S4), the amount of soft monomer used is 0.

[0090] Comparative Example 2

[0091] An organosilicon mixed sulfonate is composed of sulfonate flame retardant KSS and organosilicon toughening agent S-2501 mixed in a weight ratio of 3:90.

[0092] Example 5

[0093] The organosilicon sulfonates of Examples 1-3 and Comparative Example 1, and the organosilicon mixed sulfonate of Comparative Example 2 were respectively applied to PC modified materials. They were added to polycarbonate according to the mass parts listed in Table 1. After dispersion and mixing, the materials were melted, mixed, extruded, water-cooled, and pelletized by a twin-screw extruder. The particles were then dried to obtain PC modified materials.

[0094] The temperature settings for each zone of the twin-screw extruder are as follows: Zone 1 240-250℃, Zone 2 260-270℃, Zone 3 260-270℃, Zone 4 260-270℃, Zone 5 250-260℃, Zone 6 240-250℃, Zone 7 230-240℃, Zone 8 220-230℃, and the die head temperature is 220-230℃; the vacuum is controlled at -0.07MPa.

[0095] Table 1

[0096]

[0097] The flame retardancy rating and notched impact strength of the implementation samples 1-3 and the control samples 1-3 were tested respectively. The test results are shown in Table 2 below:

[0098] Table 2

[0099]

[0100] As shown in Table 2 above, the core-shell structured organosilicon sulfonate of the present invention has excellent flame retardant effect on PC and excellent impact resistance at low temperatures.

[0101] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for preparing an organosilicon sulfonate that combines low-temperature toughening and flame retardancy, characterized in that, Includes the following steps: (S1) After mixing organosilicon DMC and mercaptosilane coupling agent, the mixture is subjected to high-speed shearing at a speed of 4000-10000 rpm using a homogenizer for 5-30 minutes to obtain organosilicon mixture. (S2) Add an aqueous solution containing a catalyst and an emulsifier to the organosilicon mixture and react at 80-100°C for 5-10 hours to obtain an organopolysiloxane core emulsion; (S3) Adjust the pH of the organopolysiloxane core emulsion to the range of 9-12, add p-styrene sulfonate and 1-hydroxycyclohexylphenyl ketone, and stir the reaction at 50-90℃ and under UV light at a wavelength of 365nm for 5-10h to obtain sulfonate-grafted organosilicon core emulsion. (S4) Add soft monomer, initiator and crosslinking agent to the sulfonate-grafted organosilicon core emulsion, and continue to stir and react at 50-90°C for 5-10 h. Then add hard monomer and continue to stir and react at 50-90°C for 5-10 h to obtain a polymer emulsion with a core-shell structure. (S5) After diluting the polymer emulsion with the core-shell structure, a demulsifier is added for demulsification treatment. After centrifugation and drying and pulverization, an organosilicon sulfonate with both low-temperature toughening and flame retardancy is obtained. The organosilicon DMC is at least one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecylcyclohexasiloxane.

2. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S1), the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane and / or 3-mercaptopropyltrimethoxysilane; wherein the mercaptosilane coupling agent accounts for 10%-50% of the molar percentage of the organosilicon mixture.

3. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S2), the catalyst is an acidic catalyst, and the emulsifier is at least one of cationic surfactant, anionic surfactant, and nonionic surfactant; wherein the total mass of the organosilicon mixture accounts for 20%-40% of the mass of the aqueous phase, the amount of the catalyst is 1%-5% of the mass of the organosilicon mixture, and the amount of the emulsifier is 1%-20% of the mass of the organosilicon mixture.

4. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S3), the p-styrene sulfonate is potassium p-styrene sulfonate and / or sodium p-styrene sulfonate; wherein the p-styrene sulfonate accounts for 10%-80% of the total mercaptosilane coupling agent in molar percentage, and the amount of 1-hydroxycyclohexylphenyl ketone is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

5. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S4), the soft monomer is at least one of 2-ethylhexyl acrylate, butyl acrylate, and lauryl methacrylate; the hard monomer is at least one of acrylic acid, methacrylic acid, methyl methacrylate, isobornyl methacrylate, styrene, methylstyrene, acrylonitrile, acrylamide, and N-hydroxymethylacrylamide; and the initiator is at least one of organic peroxide initiator, inorganic peroxide initiator, azo initiator, or redox initiator.

6. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S4), the crosslinking agent is at least one selected from allyl methacrylate, triallyl cyanurate, triallyl isocyanurate, allyl maleate, diallyl fumarate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, diallylamine, triallylamine, divinylbenzene, trivinylbenzene, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, and trimethylolmethane trimethacrylate.

7. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S4), the amount of the soft monomer is 5%-15% of the mass of the organopolysiloxane core emulsion, the amount of the crosslinking agent is 0.1%-1% of the mass of the organopolysiloxane core emulsion, the amount of the hard monomer is 25%-45% of the mass of the organopolysiloxane core emulsion, and the amount of the initiator is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

8. The method for preparing an organosilicon sulfonate with both low-temperature toughening and flame retardancy according to claim 1, characterized in that: In step (S5), the demulsifier is a metal salt solution and / or a water-soluble organic solvent; the amount of the demulsifier is 0.5-3 times the mass of the polymer emulsion with a core-shell structure.

9. An organosilicon sulfonate possessing both low-temperature toughening and flame retardancy, characterized in that: It is prepared by the method for preparing organosilicon sulfonates as described in any one of claims 1-8.

10. An application of the organosilicon sulfonate as described in claim 9, characterized in that: The organosilicon sulfonate, which combines low-temperature toughening and flame retardancy, is used for low-temperature toughening and flame retardant modification of polycarbonate.

Images