Organosilicon sulfonate with low-temperature toughening and flame-retardant functions as well as preparation method and application thereof

Abstract

The invention relates to the technical field of synthesis of organic silicon sulfonate, in particular to a preparation method of organic silicon sulfonate with both low-temperature toughening and flame retardance, which adopts a one-pot preparation technology, and solves the problems of stability, compatibility, hygroscopicity and the like of a traditional flame retardant by introducing sulfonate groups and utilizing a surface coating modification technology of a core-shell structure. Specifically, polysiloxane is adopted as an inner core carrier, silicon of a sulfydryl functional group is utilized, a sulfonate group is bonded through a sulfydryl alkene click chemical reaction, the sulfonate group is introduced into a side chain of the inner core carrier, sulfonate can effectively avoid the problem that small-molecule sulfonate is separated out in the inner core, and therefore the stability of the inner core carrier in the using process is guaranteed. Under the action of an initiator and a cross-linking agent, a sulfonate grafted organic silicon core is coated with a soft monomer and a hard monomer polymer, and a formed core-shell structure not only has a flame-retardant effect, but also has a low-temperature toughening effect.

Description

Technical Field

[0001] The present invention relates to the technical field of synthetic organosilicon sulfonates, and particularly relates to an organosilicon sulfonate with both low-temperature toughening and flame retardancy, a preparation method thereof, and an application thereof. Background Art

[0002] Organosiloxanes have been widely used in many industrial fields due to their excellent properties, especially showing significant advantages in high temperature resistance, antioxidant degradation, and environmental friendliness. These properties make them key materials in fields such as high-performance plastic 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, especially showing unique superiority in the flame retardant modification of polycarbonate (PC) materials.

[0003] Existing sulfonate flame retardants, such as KSS, have certain limitations in the application in the PC matrix as small molecules; due to their small molecular size, the physical entanglement with the PC matrix is weak, and they are prone to precipitation, which in turn leads to the attenuation of the flame retardant effect during long-term use. Therefore, the effect of using small molecule sulfonates alone as flame retardants is limited, and their application scope is relatively narrow.

[0004] Although there is a shell structure in the prior art with sulfonates and monomers grafted on the surface of an organosilicon core as a flame retardant, its sulfonates are still exposed, having problems of being more prone to moisture absorption and insufficient compatibility with resins, which have an adverse impact on flame retardancy and low-temperature toughening, and are not conducive to being used as a flame retardant type low-temperature toughening agent. Summary of the Invention

[0005] In order to overcome the disadvantages and deficiencies existing in the prior art, one of the purposes of the present invention is to provide a preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy. By using a one-pot preparation technique, the problems of the stability, compatibility, and moisture absorption of traditional flame retardants are solved by introducing sulfonate groups and using the surface coating modification technique of the core-shell structure. Specifically, polysiloxane is used as the core carrier, and sulfonate groups are introduced into its side chains by bonding sulfonate groups through thiol-ene click chemical reactions with silicon of thiol functional groups. The sulfonate in the core can effectively avoid the precipitation problem of small molecule sulfonates, thereby ensuring its stability during use. Under the action of an initiator and a crosslinking agent, the sulfonate-grafted organosilicon core is coated with soft monomers and hard monomer polymers. The formed core-shell structure not only improves the compatibility with different substrates, but also can effectively solve the moisture absorption and hydrophilicity problems of sulfonates, while maintaining the flame retardant activity of sulfonates, thereby improving the flame retardant efficiency; this preparation method is simple to operate, convenient to control, has high production efficiency and low production cost, and can be used for large-scale production.

[0006] The second object of the present invention is to provide an organosilicon sulfonate with both low-temperature toughening and flame retardancy. The sulfonate-grafted organosilicon is used as the core, and soft monomers and hard monomers are used as the shell to wrap the sulfonate inside the shell, reduce the water absorption of the organosilicon sulfonate, and improve the compatibility of the organosilicon sulfonate with the resin. It not only has a flame retardant effect but also has a low-temperature toughening effect.

[0007] The third object of the present invention is to provide an application of an organosilicon sulfonate with both low-temperature toughening and flame retardancy. The coating layer of the organosilicon sulfonate can provide additional physical protection for the polysiloxane containing sulfonate, reduce direct contact with the external environment, and thus greatly improve its dispersibility in the PC resin material; while the core-shell structured organosilicon sulfonate has a multi-layer structure, a soft monomer polymerization layer with a low glass transition temperature, which has a low glass transition temperature. The prepared organosilicon sulfonate has excellent weather resistance, good low-temperature resistance, and can also enhance the low-temperature toughening effect on polycarbonate (PC) materials, which is particularly important for improving its performance in low-temperature environments.

[0008] The first object of the present invention is achieved by the following technical solution: A preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy, comprising the following steps:

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

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

[0011] (S3) Adjust the pH of the organopolysiloxane core emulsion to the range of 9 - 12, add styrene sulfonate and 1-hydroxycyclohexyl phenyl ketone, and stir and react at 50 - 90 °C and under UV light conditions with a wavelength of 365 nm for 5 - 10 h to obtain a sulfonate-grafted organosilicon core emulsion;

[0012] (S4) Add soft monomers, initiators, and crosslinkers to the sulfonate-grafted organosilicon core emulsion, continue to stir and react at a temperature of 50 - 90 °C for 5 - 10 h, then add hard monomers, and continue to stir and react at a temperature of 50 - 90 °C for 5 - 10 h to obtain a polymer emulsion with a core-shell structure;

[0013] (S5) Dilute the polymer emulsion with a core-shell structure, add a demulsifier for demulsification treatment, and after centrifugal separation and drying and pulverization treatment, obtain an organosilicon sulfonate with both low-temperature toughening and flame retardancy.

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

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

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

[0017] Further, the cationic surfactants include at least one of alkyltrimethyl quaternary ammonium salts, dialkyldimethyl quaternary ammonium salts, benzylalkyldimethyl quaternary ammonium salts, monoalkyl quaternary ammonium salts, alkylphenol polyoxyethylene quaternary ammonium salts, N-alkyldiethanolamine salts, pyridinium salts, imidazolines, and morpholines. The anionicsurfactants include at least one of alkyl sulfates, alkylbenzenesulfonates, fatty acid salts, alkyl hydrogen sulfates, N-acyltaurines, alkylbenzenesulfonates, alkylnaphthalenesulfonates, alkyldiphenyl ether disulfonates, dialkyl sulfosuccinates, monoalkyl sulfosuccinates, N-acyl amino acid salts, and alkyl phosphates. The non-ionic surfactants include at least one of glycerol monostearate, sorbitan fatty acid esters, glycerol fatty acid esters, polyglycerol fatty acid esters, and propylene glycol fatty acid esters.

[0018] Preferably, in the step (S3), the styrene sulfonate is potassium styrene sulfonate and / or sodium styrene sulfonate; wherein, the molar percentage of the styrene sulfonate in the total mercapto-silane coupling agent is 10%-80%, and the dosage of the 1-hydroxycyclohexyl phenyl ketone is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

[0019] Preferably, in the 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, α-methylstyrene, acrylonitrile, acrylamide and N-methylolacrylamide, and the initiator is at least one of organic peroxide initiators, inorganic peroxide initiators, azo initiators or redox initiators.

[0020] Adopting the above technical solution, the above soft monomer has the characteristics of low glass transition temperature, excellent weather resistance and good low-temperature resistance, playing an important role in low-temperature toughening; the above hard monomer has the characteristics of high glass transition temperature, endowing sufficient cohesive strength, improving the tensile strength, and having good chemical stability and dimensional stability. Further, the organic peroxide initiators include at least one of benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, diisopropylbenzene peroxide, tert-butyl peroxybenzoate, tert-butyl peroxy pivalate, methyl ethyl ketone peroxide, cyclohexanone peroxide, diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate. The inorganic peroxide initiators include at least one of potassium persulfate, sodium persulfate and ammonium persulfate. The azo initiators include at least one of azobisisobutyronitrile, azobisisoheptonitrile, dimethyl azobisisobutyrate and 2,2'-azobis(2,4-dimethylvaleronitrile). The redox initiators include at least one of benzoyl peroxide / sucrose, tert-butyl hydroperoxide / rongalite, tert-butyl hydroperoxide / sodium metabisulfite, ammonium persulfate / sodium bisulfite, potassium persulfate / sodium bisulfite, hydrogen peroxide / tartaric acid, hydrogen peroxide / rongalite, ammonium persulfate / ferrous sulfate, hydrogen peroxide / 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, hydrogen peroxide / ferrous chloride and cumene hydroperoxide / tetraethylenimine.

[0021] Preferably, in the step (S4), the crosslinking agent is at least one of 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 the step (S4), the dosage of the soft monomer is 5%-15% of the mass of the organopolysiloxane core emulsion, the dosage of the crosslinking agent is 0.1%-1% of the mass of the organopolysiloxane core emulsion, the dosage of the hard monomer is 25%-45% of the mass of the organopolysiloxane core emulsion; and the dosage of the initiator is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

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

[0024] Further, 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 object of the present invention is achieved by the following technical solution: an organosilicate sulfonate with both low-temperature toughening and flame retardancy, which is prepared by the preparation method of the organosilicate sulfonate as described above.

[0026] The third object of the present invention is achieved by the following technical solution: the application of the above-mentioned organosilicate sulfonate with both low-temperature toughening and flame retardancy, and the organosilicate sulfonate with both low-temperature toughening and flame retardancy is used for the low-temperature toughening and flame retardant modification of polycarbonate.

[0027] The beneficial effects of the present invention are as follows: A preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy is efficiently synthesized by using a one-pot preparation technique. By introducing sulfonate groups and utilizing the surface coating modification technique of the core-shell structure, the compatibility is improved, the hygroscopicity of the sulfonate groups is reduced, and the flame retardancy efficiency is enhanced, solving problems such as the stability, compatibility, and hygroscopicity of traditional flame retardants. Specifically, polysiloxane is used as the core carrier, and sulfonate groups are introduced into its side chains by bonding sulfonate groups through thiol-ene click chemical reactions with silicon of thiol-functionalized silanes. The sulfonate in the core can effectively avoid the problem of precipitation of small-molecule sulfonates, thus ensuring its stability during use. Under the action of an initiator and a crosslinking agent, the sulfonate-grafted organosilicon core is coated with soft monomers and hard monomer polymers to form a core-shell structure, which not only improves the compatibility with different substrates but also effectively solves the hygroscopicity and hydrophilicity problems of sulfonates while maintaining the flame retardant activity of sulfonates, thereby enhancing the flame retardancy efficiency. This preparation method is simple to operate, convenient to control, has high production efficiency and low production cost, and can be used for large-scale production.

[0028] The organosilicon sulfonate with both low-temperature toughening and flame retardancy of the present invention has a sulfonate-grafted organosilicon as the core, and the shell structure is successively polymerized from the inside out by acrylate soft monomers and hard monomers. The glass transition temperature of the soft monomer polymer layer with a low glass transition temperature is relatively low. The prepared organosilicon sulfonate has excellent weather resistance, good low-temperature resistance, and 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 resins. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the synthesis mechanism of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments and the accompanying drawings. The content mentioned in the embodiments does not limit the present invention.

[0031] Example 1

[0032] A preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy includes the following steps:

[0033] (S1) Take organosilicon DMC and a mercapto-silane coupling agent, mix them, and use a homogenizer to perform high-speed shearing at a speed of 8000 rpm for 15 minutes to obtain an organosilicon mixture;

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

[0035] (S3) Adjust the pH of the organopolysiloxane core emulsion to 9, add sodium p-styrenesulfonate and 1-hydroxycyclohexyl phenyl ketone, and stir and react for 7 h under the conditions of 80 °C and UV light with a wavelength of 365 nm to obtain a sulfonate-grafted silicone core emulsion;

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

[0037] (S5) After diluting the polymer emulsion with a core-shell structure, add a demulsifier for demulsification treatment, and after centrifugal separation and drying and pulverization treatment, obtain an organosilicon sulfonate with both low-temperature toughening and flame retardancy.

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

[0039] In the step (S2), the total mass of the organosilicon mixture accounts for 30% of the mass of the aqueous phase, the dosage of the catalyst is 1% of the mass of the organosilicon mixture, the dosage 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 sorbitan fatty acid ester in a weight ratio of 4:1.

[0040] In the step (S3), the sodium p-styrenesulfonate is sodium p-styrenesulfonate; wherein, the molar percentage of the sodium p-styrenesulfonate in the total mercapto-silane coupling agent is 50%, and the dosage of 1-hydroxycyclohexyl phenyl ketone is 0.5% of the mass of the organopolysiloxane core emulsion.

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

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

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

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

[0045] Example 2

[0046] A preparation method of an organosilicon sulfonate with both low-temperature toughness and flame retardancy includes the following steps:

[0047] (S1) Take octamethylcyclotetrasiloxane (D4) as the organosilicon DMC and 3-mercaptopropyltriethoxysilane as the mercapto silane coupling agent. After mixing them, use a homogenizer to perform high-speed shearing at a speed of 8000 rpm for 5 minutes to obtain an 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 styrene sulfonate and 1-hydroxycyclohexyl phenyl ketone, and stir and react at 60 °C under UV light with a wavelength of 365 nm for 6 hours to obtain a sulfonate-grafted organosilicon core emulsion.

[0050] (S4) Add a soft monomer, an initiator, and a crosslinking agent to the sulfonate-grafted organosilicon core emulsion, continue to stir and react at 60 °C for 6 hours, then add a 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) Dilute the polymer emulsion with a core-shell structure, add a demulsifier for demulsification treatment, and after centrifugal separation and drying and pulverization treatment, obtain an organosilicon sulfonate with both low-temperature toughness and flame retardancy.

[0052] In the step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercapto silane coupling agent is 3-mercaptopropyltriethoxysilane; among them, the molar percentage of the mercapto silane coupling agent in the organosilicon mixture is 20%.

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

[0054] In the step (S3), the styrene sulfonate is sodium styrene sulfonate; wherein, the molar percentage of the styrene sulfonate in the total mercapto silane coupling agent is 20%, and the dosage of 1-hydroxycyclohexyl phenyl ketone is 0.2% of the mass of the organopolysiloxane core emulsion.

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

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

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

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

[0059] Example 3

[0060] A preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy includes the following steps:

[0061] (S1) Mix organosilicon DMC and mercapto silane coupling agent, and use a homogenizer to carry out high-speed shearing at a speed of 8000 rpm for 30 min to obtain an 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 h to obtain an organopolysiloxane core emulsion;

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

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

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

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

[0067] In the step (S2), the total mass of the organosilicon mixture accounts for 40% of the mass of the aqueous phase, the dosage of the catalyst is 3% of the mass of the organosilicon mixture, the dosage 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 sorbitan fatty acid ester in a weight ratio of 5:1.

[0068] In the step (S3), the styrene sulfonate is a mixture of potassium styrene sulfonate and sodium styrene sulfonate in a molar ratio of 1:5; among them, the molar percentage of the styrene sulfonate in the total mercapto-silane coupling agent is 50%, and the dosage of 1-hydroxycyclohexyl phenyl ketone is 1% of the mass of the organopolysiloxane core emulsion.

[0069] In the 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 the step (S4), the crosslinking agent is allyl methacrylate.

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

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

[0073] Example 4

[0074] A preparation method of an organosilicon sulfonate with both low-temperature toughening and flame retardancy, comprising the following steps:

[0075] (S1) Mix octamethylcyclotetrasiloxane (D4) as the organosilicon DMC and 3-mercaptopropyltriethoxysilane as the mercapto-silane coupling agent, and then use a homogenizer to perform high-speed shearing at a speed of 8000 rpm for 20 minutes to obtain an 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 sodium p-styrenesulfonate and 1-hydroxycyclohexyl phenyl ketone, and stir and react under UV light at 80 °C and a wavelength of 365 nm for 8 hours to obtain a sulfonate-grafted organosilicon core emulsion;

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

[0079] (S5) Dilute the polymer emulsion with a core-shell structure, add a demulsifier for demulsification treatment, and after centrifugal separation and drying and pulverization treatment, obtain an organosilicon sulfonate with both low-temperature toughening and flame retardancy.

[0080] In the step (S1), the organosilicon DMC is octamethylcyclotetrasiloxane (D4), and the mercapto-silane coupling agent is 3-mercaptopropyltriethoxysilane; among them, the molar percentage of the mercapto-silane coupling agent in the organosilicon mixture is 30%.

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

[0082] In the step (S3), the sodium p-styrenesulfonate is used as the sodium p-styrenesulfonate; among them, the molar percentage of the sodium p-styrenesulfonate in the total mercapto-silane coupling agent is 40%, and the dosage of the 1-hydroxycyclohexyl phenyl ketone is 0.8% of the mass of the organopolysiloxane core emulsion.

[0083] In the 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 the step (S4), the crosslinker is allyl methacrylate.

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

[0086] In the step (S5), the demulsifier is calcium chloride; the dosage 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 that:

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

[0090] Comparative Example 2

[0091] An organosilicon mixed sulfonate is composed of a sulfonate flame retardant KSS and an 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, as well as the organosilicon mixed sulfonate of Comparative Example 2, were respectively applied to PC modified materials, added to polycarbonate according to the parts by mass listed in Table 1. After dispersion and mixing, melting, kneading, extrusion, water cooling, and pelletizing processes were carried out through a twin-screw extruder, and the pellets were dried to obtain PC modified materials;

[0094] Among them, the temperature of each zone of the twin-screw extruder was set as follows: Zone 1: 240 - 250 °C, Zone 2: 260 - 270 °C, Zone 3: 260 - 270 °C, Zone 4: 260 - 270 °C, Zone 5: 250 - 260 °C, Zone 6: 240 - 250 °C, Zone 7: 230 - 240 °C, Zone 8: 220 - 230 °C, and the head temperature: 220 - 230 °C; the vacuum was controlled at -0.07 MPa.

[0095] Table 1

[0096]

[0097] The flame retardant grades and notch impact strengths of Samples 1-3 and Comparative Samples 1-3 were tested respectively, and the test results are shown in Table 2 below:

[0098] Table 2

[0099]

[0100] As can be seen from Table 2 above, the silicone sulfonate with a core-shell structure of the present invention has excellent flame retardancy for PC and excellent impact resistance at low temperatures.

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

Claims

1. A method for preparing an organic silicon sulfonate having both low temperature toughening and flame retardancy, characterized in that: The steps include: (S1), after mixing the organosilicon DMC and the mercaptosilane coupling agent, high-speed shearing is performed by a homogenizer at a speed of 4000-10000 rpm for 5-30 minutes to obtain an organosilicon mixture; (S2), adding an aqueous solution containing a catalyst and an emulsifier to the organic silicon mixture, reacting at a temperature of 80-100° C. for 5-10 hours to obtain an organic polysiloxane core emulsion; (S3), adjusting the pH of the organopolysiloxane core emulsion to a range of 9-12, adding p-styrene sulfonate and 1-hydroxycyclohexyl phenyl ketone, and stirring the reaction at 50-90° C. and 365 nm UV light for 5-10 h to obtain a sulfonate-grafted organosilicon core emulsion; (S4), adding a soft monomer, an initiator and a crosslinking agent to the sulfonate grafted silicone core emulsion, continuing to stir and react at a temperature of 50-90° C. for 5-10 hours, and then adding a hard monomer, continuing to stir and react at a temperature of 50-90° C. for 5-10 hours to obtain a polymer emulsion with a core-shell structure; (S5) diluting the core-shell structure polymer emulsion, adding a demulsifier for demulsification treatment, and performing centrifugal separation and drying and crushing treatment to obtain an organic silicon sulfonate having both low-temperature toughening and flame retardancy.

2. The method for preparing an organic silicon sulfonate having both low temperature toughening and flame retardancy according to claim 1, characterized in that: In the step (S1), the organosilicon DMC is at least one of hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6), and the mercaptosilane coupling agent is 3-mercaptopropyltriethoxysilane and / or 3-mercaptopropyltrimethoxysilane; wherein the molar percentage of the mercaptosilane coupling agent in the organosilicon mixture is 10%-50%.

3. The method for preparing an organic silicon sulfonate having both low temperature toughening and flame retardancy according to claim 1, characterized in that: In the step (S2), the catalyst is an acidic catalyst, and the emulsifier is at least one of a cationic surfactant, an anionic surfactant and a 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 organic silicon sulfonate having both low temperature toughening and flame retardancy according to claim 1, characterized in that: In the step (S3), the p-styrene sulfonate is potassium p-styrene sulfonate and / or sodium p-styrene sulfonate; wherein the molar percentage of the p-styrene sulfonate in the total mercaptosilane coupling agent is 10%-80%, and the amount of the 1-hydroxycyclohexyl phenyl ketone is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

5. The method for preparing an organic silicon sulfonate having both low temperature toughening and flame retardancy according to claim 1, characterized in that: In the 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, methyl styrene, acrylonitrile, acrylamide and N-hydroxymethyl acrylamide, and the initiator is at least one of an organic peroxide initiator, an inorganic peroxide initiator, an azo initiator or a redox initiator.

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

7. The method for preparing an organic silicon sulfonate having both low temperature toughening and flame retardancy according to claim 1, characterized in that: In the 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; the amount of the initiator is 0.1%-2% of the mass of the organopolysiloxane core emulsion.

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

9. An organic silicon sulfonate having both low temperature toughening and flame retardancy, characterized in that: The organic silicon sulfonate is prepared by the preparation method of the organic silicon sulfonate according to any one of claims 1 to 8.

10. An application of the organic silicon sulfonate having both low temperature toughening and flame retardancy as claimed in claim 9, characterized in that: The organic silicon sulfonate with both low-temperature toughening and flame retardancy is used for low-temperature toughening and flame retardancy modification of polycarbonate.

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