Preparation method of active nano silicone rubber core-shell particle pre-dispersion liquid

Abstract

The invention discloses a preparation method of active nano silicone rubber core-shell particle pre-dispersion liquid. The preparation method comprises the following steps: pre-emulsifying an organic silicon monomer, a silane coupling agent and a vinyl silane coupling agent, then carrying out hydrolytic polycondensation under the condition of an acid catalyst, synthesizing a nano silicon rubber core particle emulsion, taking the nano silicon rubber core particle emulsion as a seed, dropwise adding a double-bond-containing pre-emulsion under the condition of the catalyst, grafting a double-bond-containing monomer shell through the vinyl silane coupling agent, and carrying out vacuum drying to obtain the nano silicon rubber core particle emulsion. The preparation method comprises the following steps: preparing a nano silicone rubber core-shell particle emulsion, taking the nano silicone rubber core-shell particle emulsion as a seed, dropwise adding a functional monomer pre-emulsion, grafting a reactive group shell to obtain an active nano silicone rubber multi-layer core-shell particle emulsion, carrying out spray drying on the emulsion, and uniformly dispersing the emulsion in epoxy resin in a melt blending manner to prepare an active nano silicone rubber core-shell particle pre-dispersion liquid. The pre-dispersion liquid prepared by the invention has the characteristics of good UV light permeability, toughness, heat resistance, electrical performance and the like, so that the pre-dispersion liquid has good application value in the fields of 3D printing, electronics, aerospace and the like.

Description

Technical Field

[0001] The invention relates to the field of organic chemical synthesis, and in particular to a method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles. Background Art

[0002] Epoxy resins are polymers containing two or more epoxy groups and composed of organic compounds such as alicyclic, aliphatic, or aromatic groups as their main chains. Epoxy resins include glycidyl esters, glycidyl ethers, alicyclic epoxy compounds, and glycidyl amines. The most widely used of these is bisphenol A glycidyl ether epoxy resin. Epoxy resins are easy to process and mold, are inexpensive, and offer excellent adhesive properties, mechanical properties, chemical stability, high and low temperature resistance, and low shrinkage during curing. They are the most widely used and most widely used matrix resin in the manufacture of polymer-based composites. However, the high crosslink density and low toughness of epoxy resins after curing result in poor fatigue and impact resistance. Furthermore, the basic structure of the cured product dictates a low temperature rating, significantly limiting their application in high-tech fields. Consequently, research on toughening, high-temperature resistance, and processability of epoxy resins has been a hot topic.

[0003] Toughening modification methods primarily focus on toughening rubber elastomers and toughening epoxy matrix resins with thermoplastic resins. Rubber toughening often results in a decrease in the elastic modulus and glass transition temperature of the modified system, making it unsuitable for applications requiring high-temperature resistance. Toughening epoxy matrix resins with thermoplastic resins significantly affects viscosity, reducing the resin's ability to wet fiber materials and failing to meet the requirements of hot-melt prepreg processes. Therefore, epoxy resins that combine toughness, heat resistance, strength, and excellent processability have long been the focus of epoxy resin modification.

[0004] Core-shell particles are a type of toughening agent with a rubber core and a polymer shell. The rubber core provides impact resistance, while the polymer shell provides excellent compatibility with epoxy resins. Core-shell particles simply need to be blended with the epoxy resin; there's no need for dissolution or phase separation during curing. When well dispersed, they can significantly improve the toughness of the system. Because there's no rubber to dissolve in the resin, the addition of core-shell particles has a minimal impact on the thermal properties of the epoxy resin. Furthermore, compared to rubber-based toughening agents, core-shell particle toughening agents have a lesser effect on the viscosity of the system.

[0005] Non-patent literature (Feng Meng. South China University of Technology, 2015.) reported that a nano-silicone rubber core-shell structure polymer was prepared with polysiloxane as the core, polybutyl acrylate as the transition layer, and polymethyl methacrylate as the shell. The PSiO-BA-MMA copolymer powder was obtained by demulsification, washing, and drying. Chinese patent application CN107151296B reported a method for preparing a large-particle core-shell structure polysiloxane-acrylate / styrene copolymer. However, these methods have the following characteristics: (1) Directly adding the shell monomer during the polysiloxane core-shell connection easily leads to demulsification, and the polymerization process is difficult to control. (2) The preparation of the nano-silicone rubber core-shell structure polymer requires tedious steps such as demulsification, filtration, and freeze drying. (3) Its application in epoxy resin toughening does not involve functional group reactions. Therefore, how to prepare a nano-silicone rubber core-shell structure polymer that has both a stable core-shell emulsion polymerization process and a simple way to obtain a reactive nano-silicone rubber core-shell structure polymer is a great technical challenge. Summary of the Invention

[0006] In order to solve the problems of the prior art, the object of the present invention is to provide a method for preparing a pre-dispersion liquid of active nano-silicone rubber core-shell particles.

[0007] In order to achieve the above object, the technical solution adopted in the present invention is: A method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles, the steps and conditions are as follows: (1) By weight, 500 parts of organosilicon monomer, 2-50 parts of emulsifier, 10-80 parts of silane coupling agent, 10-80 parts of vinyl silane coupling agent, and 250-400 parts of deionized water are emulsified in a high shear emulsifier for 3 minutes to 10 minutes to obtain an organosilicon pre-emulsion; 2-30 parts of acid catalyst and 200-250 parts of deionized water are mixed uniformly to obtain an acid catalyst solution; (2) By weight, 1-25 parts of emulsifier and 40-160 parts of deionized water are mechanically stirred and heated to 40°C-70°C, 1%-20% of the organosilicon pre-emulsion prepared in step (1) and 5%-40% of the acid catalyst are added, the temperature is raised to 70°C-95°C and the reaction is carried out for 15min-60min, the remaining organosilicon pre-emulsion and acid catalyst are added dropwise within 1h-4h, the reaction is carried out at a constant temperature for 2h-6h, the pH is adjusted to 5-9 with ammonia water, and the nano-silicone rubber core particle emulsion is obtained by filtration; (3) By weight, 5-50 parts of double bond-containing monomer, 0.01-5 parts of emulsifier, and 3-30 parts of deionized water are emulsified in a high shear emulsifier for 3 min-10 min to obtain a double bond-containing pre-emulsion; 1-25 parts of functional monomer, 0.01-5 parts of emulsifier, and 1-30 parts of deionized water are emulsified in a high shear emulsifier for 3 min-10 min to obtain a functional monomer emulsion; 0-1 parts of buffer and 0-10 parts of deionized water are stirred and dissolved to obtain a buffer solution; 0.01-5 parts of catalyst and 1-200 parts of deionized water are stirred and dissolved to obtain a catalytic solution; (4) By weight, 100 parts of nano silicone rubber core particle emulsion, 0.01-5 parts of emulsifier, 0-50 parts of deionized water and the buffer solution prepared in step (3) are stirred and heated to 40-90°C, and the double bond-containing pre-emulsion prepared in step (3) and part of the catalyst solution are added dropwise within 1 hour to 4 hours, and the reaction is carried out at a constant temperature for 1 hour to 6 hours to prepare a nano silicone rubber core-shell particle emulsion; (5) Cooling to 30-80°C, adding the functional monomer emulsion prepared in step (3) and the remaining catalyst solution to the nano-silicone rubber core-shell particle emulsion within 1-60 minutes, heating to 40-90°C and reacting for 1-6 hours to prepare an active nano-silicone rubber core-shell particle emulsion; (6) By weight, 100 parts of active nano silicone rubber core-shell particle emulsion and 50-300 parts of deionized water are mixed evenly, and spray dried at 120°C-220°C to obtain active nano silicone rubber core-shell particle powder; (7) Add 10-75 parts by weight of the prepared active nano silicone rubber core-shell particle powder to 100 parts of epoxy resin, and melt-blend at 50°C-180°C for 0.5h-12h to prepare a pre-dispersion of active nano silicone rubber core-shell particles.

[0008] Preferably, the organosilicon monomer in step (1) is one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and low molecular weight hydroxy silicone oil.

[0009] Preferably, the emulsifier in steps (1) to (4) is one of sodium docusate, sodium dodecylsulfonate, sodium dodecylbenzenesulfonate, dodecylbenzenesulfonic acid, sodium didodecylphenyl ether disulfonate, sodium rosinate, sodium cyclohexane, sodium ricinoleate, isomeric tridecyl alcohol ether, polyoxyethylene octylphenol ether-10, sorbitan monolaurate, and sorbitan monopalmitate, or a combination thereof.

[0010] Preferably, the silane coupling agent in step (1) is one of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltrimethoxysilane, tetraethyl silicate or a combination thereof.

[0011] Preferably, the vinyl silane coupling agent in step (1) is one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, or a combination thereof.

[0012] Preferably, the acid catalyst in step (1) is one of benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid, or a combination thereof.

[0013] Preferably, the double bond-containing monomer in step (3) is one of styrene, methyl methacrylate, butyl acrylate, isooctyl acrylate, acrylic acid, and lauryl methacrylate, or a combination thereof.

[0014] Preferably, the functional monomer in step (3) is one or a combination of epoxy-containing monomers (including but not limited to glycidyl methacrylate and allyl glycidyl ether); amino-containing monomers (including but not limited to allylamine, 4-vinylaniline, and 4-penten-1-amine); hydroxyl-containing monomers (including but not limited to hydroxyethyl methacrylate, hydroxypropyl methacrylate, and 1-penten-3-ol); and carboxyl-containing monomers (including but not limited to acrylic acid, methacrylic acid, methylenesuccinic acid, maleic acid, and crotonic acid).

[0015] Preferably, the buffer in step (3) is one of sodium bicarbonate, sodium formate, sodium acetate, ammonium acetate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, and sodium phosphate, or a combination thereof.

[0016] Preferably, the catalyst in step (3) is one of ammonium persulfate and potassium persulfate.

[0017] Preferably, the epoxy resin in step (7) is one of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, epoxidized olefin compound, heterocyclic epoxy resin and mixed epoxy resin, or a combination thereof.

[0018] The present invention adopts the above technical scheme, the organic silicon monomer, silane coupling agent, vinyl silane coupling agent are pre-emulsified with water and emulsifier, and hydrolyzed and condensed under acid catalyst conditions by seed emulsion polymerization to synthesize nano silicone rubber core particle emulsion, then the nano silicone rubber core particle emulsion is used as a seed, under catalyst conditions, a double bond pre-emulsion is added dropwise, and a double bond monomer shell is grafted onto the nano silicone rubber core-shell particle emulsion through a vinyl silane coupling agent, to obtain a nano silicone rubber core-shell particle emulsion, and finally the nano silicone rubber core-shell particle emulsion is used as a seed, a functional monomer pre-emulsion is added dropwise, and a reactive group shell is grafted onto the reactive group shell to obtain an active nano silicone rubber multilayer core-shell particle emulsion, and the emulsion is spray-dried to obtain an active nano silicone rubber core-shell particle powder, wherein the reactive groups are epoxy, amine, hydroxyl, and carboxyl groups, which can react with epoxy groups and can be uniformly dispersed in epoxy resin by melt blending to toughen it. Compared with the prior art, the beneficial effects achieved by the present invention are: 1. When the polysiloxane core is connected to the shell, the shell monomer is pre-emulsified. With the protection of the emulsifier, the problem of demulsification caused by the direct dropwise addition of the shell monomer is solved, and the polymerization process is carried out stably.

[0019] 2. The present invention directly obtains nano silicone rubber core-shell particle powder by spray drying, which has low cost, simple process, high production efficiency and can be produced on a large scale.

[0020] 3. The grafted epoxy or amino shell of the present invention has reactive functional groups that can react with epoxy resin to toughen the epoxy resin, retaining its reactivity and improving its toughness to the greatest extent.

[0021] 4. While toughening the epoxy resin, the silicone rubber core and the epoxy resin have a large difference in refractive index, and can replace titanium dioxide to achieve a whitening effect. It also has good UV light transmittance, toughness, heat resistance and electrical insulation, and can be used for 3D printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a TEM image of the active nano-silicone rubber core-shell particle emulsion prepared in Example 1 of the present invention.

[0023] Figure 2 This is a physical picture of the active nano-silicone rubber core-shell particle powder prepared in Example 1 of the present invention.

[0024] Figure 3 This is a synthesis route diagram of the active nano silicone rubber core-shell particle pre-dispersion liquid of the present invention.

[0025] Figure 4 This is a model printed by a 355nm 3D printer after adding the active nano-silicone rubber core-shell particle pre-dispersion prepared in Example 1 of the present invention to the formula. DETAILED DESCRIPTION

[0026] In order to further explain the technical solution of the present invention, the present invention is described in detail below through specific embodiments. Example

[0027] (1) Add 1 g of sodium dodecylbenzenesulfonate, 50 g of deionized water, 100 g of octamethylcyclotetrasiloxane, 3 g of methyltriethoxysilane, and 3 g of γ-methacryloyloxypropyltrimethoxysilane to a beaker in sequence, and emulsify for 3 min using a high shear emulsifier to obtain a silicone pre-emulsion; add 0.7 g of sulfuric acid and 50 g of deionized water to a beaker and stir to mix uniformly to obtain an acid catalyst solution.

[0028] (2) Add 1 g of sodium dodecylbenzenesulfonate and 30 g of deionized water to a four-necked flask equipped with a reflux condenser and a mechanical stirrer in a constant temperature water bath jacket, stir and heat to 50°C, add 6% of the organosilicon pre-emulsion and 15% of the acid catalyst prepared in step (1), heat to 75°C and react for 60 minutes, then add the remaining organosilicon pre-emulsion and acid catalyst dropwise within 2 hours, react at a constant temperature for 5 hours, adjust the pH to 8 with ammonia water, and filter to obtain a nano-silicone rubber core particle emulsion with a solid content of 43.9% and an average particle size of 175 nm.

[0029] (3) 0.5 g of sodium dodecylbenzenesulfonate, 15 g of deionized water, and 44 g of methyl methacrylate were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a methyl methacrylate pre-emulsion; 0.3 g of sodium dodecylbenzenesulfonate, 2.2 g of deionized water, and 4.4 g of allylamine were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain an allylamine emulsion; 0.2 g of sodium bicarbonate and 2 g of deionized water were added to a beaker and stirred to obtain a buffer solution; 0.2 g of potassium persulfate and 20 g of deionized water were added to a beaker and stirred to obtain a catalyst solution.

[0030] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, 0.5 g of sodium dodecylbenzenesulfonate, 20 g of deionized water, 100 g of the nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3) were added, and the mixture was stirred and heated to 75°C. Methyl methacrylate pre-emulsion and 90% of the catalyst solution prepared in step (3) were added dropwise within 1.5 h, and the reaction was carried out at a constant temperature for 2 h.

[0031] (5) Cooling to 70°C, adding allylamine emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 80°C for 1 hour to prepare an active nano-silicone rubber core-shell particle emulsion with a solid content of 44.1% and an average particle size of 210 nm; (6) Add 100 g of active nano silicone rubber core-shell particle emulsion and 100 g of deionized water into a beaker and mix well. Spray dry at 160 °C to obtain 41.6 g of active nano silicone rubber core-shell particle powder. (7) 25 g of active nano silicone rubber core-shell particle powder and 75 g of bisphenol A epoxy resin were melt-blended at 150 °C for 30 min to obtain an active nano silicone rubber core-shell particle pre-dispersion liquid.

[0032] See attached Figure 1 , which is a TEM image of the active nano silicone rubber core-shell particle emulsion prepared in Example 1 of the present invention. The center of the image is the silicone rubber core, and the outer layer is polymethyl methacrylate and polyallylamine, with a clear core-shell structure.

[0033] See attached Figure 2, which is a physical picture of the active nano silicone rubber core-shell particle powder prepared in Example 1 of the present invention. The appearance is white powder.

[0034] See attached Figure 3 The following is a synthetic route for the pre-dispersion of the active nano-silicone rubber core-shell particles of the present invention. The active nano-silicone rubber core-shell particle powder is synthesized by seeded emulsion polymerization using polysiloxane as the core, grafted PMMA as the second layer, and polyallylamine as the third layer. The powder is then melt-blended and dispersed in epoxy resin to produce the nano-silicone rubber core-shell particle pre-dispersion.

[0035] See attached Figure 4 This model was printed using a 355nm 3D printer after melt blending the active nanosilicone rubber core-shell particle powder prepared in Example 1 of the present invention with epoxy resin E51. The addition of the formula and 355nm 3D printing yielded a white model, demonstrating its successful 3D printing application. Example

[0036] (1) Add 2 g of isotridecyl ether 1305 emulsifier, 50 g of deionized water, 100 g of octamethylcyclotetrasiloxane, 9 g of methyltriethoxysilane, and 5 g of vinyltriethoxysilane to a beaker in sequence, and emulsify with a high shear emulsifier for 7 min to obtain a silicone pre-emulsion; add 0.6 g of sulfuric acid and 30 g of deionized water to a beaker and stir to mix uniformly to obtain an acid catalyst solution.

[0037] (2) Add 1 g of isomeric tridecanol ether 1305 and 30 g of deionized water to a four-necked flask equipped with a reflux condenser and a mechanical stirrer under a constant temperature water bath, stir and heat to 50°C, add 2% of the organosilicon pre-emulsion and 8% of the acid catalyst prepared in step (1), heat to 75°C and react for 60 minutes, then dropwise add the remaining organosilicon pre-emulsion and acid catalyst within 2 hours, react at a constant temperature for 5 hours, adjust the pH to 8 with ammonia water, filter and obtain a nano-silicone rubber core particle emulsion with a solid content of 51% and an average particle size of 406 nm.

[0038] (3) Add 1 g of isotridecyl alcohol ether 1305, 30 g of deionized water, and 60 g of methyl methacrylate to a beaker in sequence, and emulsify with a high shear emulsifier for 6 min to obtain a methyl methacrylate pre-emulsion; add 0.5 g of isotridecyl alcohol ether 1305, 3 g of deionized water, and 6 g of allyl glycidyl ether to a beaker in sequence, and emulsify with a high shear emulsifier for 3 min to obtain a glycidyl methacrylate emulsion; add 1 g of sodium bicarbonate and 10 g of deionized water to a beaker and stir to mix uniformly to obtain a buffer solution; add 0.8 g of potassium persulfate and 10 g of deionized water to a beaker and stir to mix uniformly to obtain a catalyst solution.

[0039] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, add 0.5 g of isomeric tridecanol ether 1305, 15 g of deionized water, 100 g of nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3), stir and heat to 85°C, add methyl methacrylate pre-emulsion and 95% of the catalyst solution prepared in step (3) dropwise within 1.5 h, and react at a constant temperature for 2 h.

[0040] (5) Cooling to 70°C, adding glycidyl methacrylate emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 80°C for 1 hour to prepare an active nano-silicone rubber core-shell particle emulsion with a solid content of 50% and an average particle size of 550 nm; (6) Add 100 g of active nano silicone rubber core-shell particle emulsion and 100 g of deionized water into a beaker and mix well. Spray dry at 150 °C to obtain 47.9 g of active nano silicone rubber core-shell particle powder.

[0041] (7) 25 g of active nano-silicone rubber core-shell particle powder and 75 g of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexylcarboxylate were melt-blended at 130°C for 30 min to obtain an active nano-silicone rubber core-shell particle pre-dispersion liquid. Example

[0042] (1) Add 1g sodium dodecylbenzenesulfonate, 0.5g OP-10, 50g deionized water, 100g octamethylcyclotetrasiloxane, 5g methyltriethoxysilane, and 3g vinyltrimethoxysilane to a beaker in sequence, and emulsify for 3 minutes using a high shear emulsifier to obtain a silicone pre-emulsion; add 0.8g sulfuric acid and 50g deionized water to a beaker and stir to mix evenly to obtain an acid catalyst solution.

[0043] (2) To a four-necked flask equipped with a reflux condenser and a mechanical stirrer, 1 g of sodium dodecylbenzenesulfonate, 0.5 g of OP-10, and 30 g of deionized water were added, and the mixture was stirred and heated to 50° C., 20% of the organosilicon pre-emulsion and 40% of the acid catalyst prepared in step (1) were added, and the mixture was heated to 85° C. and reacted for 60 min. The remaining organosilicon pre-emulsion and acid catalyst were added dropwise within 2 h, and the mixture was reacted at a constant temperature for 5 h. The pH was adjusted to 6 with ammonia water, and the mixture was filtered to obtain a nano-silicone rubber core particle emulsion with a solid content of 45% and an average particle size of 90 nm.

[0044] (3) 0.5 g of docusate sodium, 15 g of deionized water, 25 g of methyl methacrylate, and 10 g of styrene were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a double bond emulsion; 0.1 g of docusate sodium, 0.5 g of deionized water, and 1 g of glycidyl methacrylate were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a glycidyl methacrylate emulsion; 0.6 g of sodium bicarbonate and 6 g of deionized water were added to a beaker and stirred to obtain a buffer solution; 0.3 g of potassium persulfate and 20 g of deionized water were added to a beaker and stirred to obtain a catalytic solution.

[0045] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, 0.5 g of sodium docusate, 10 g of deionized water, 100 g of the nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3) were added, and the mixture was stirred and heated to 85°C. The double bond pre-emulsion and 90% of the catalyst prepared in step (3) were added dropwise within 1.5 h, and the reaction was continued at a constant temperature for 2 h.

[0046] (5) Cooling to 75°C, adding glycidyl methacrylate emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 85°C for 1 hour to prepare an active nano-silicone rubber core-shell particle emulsion with a solid content of 44% and an average particle size of 140 nm; (6) Add 100 g of nano silicone rubber core-shell particle emulsion and 100 g of deionized water into a beaker and mix well. Spray dry at 150 °C to obtain 42 g of active nano silicone rubber core-shell particle powder.

[0047] (7) 33 g of active nano silicone rubber core-shell particle powder and 67 g of bisphenol A epoxy resin were melt-blended at 150 °C for 40 min to obtain an active nano silicone rubber core-shell particle pre-dispersion liquid. Example

[0048] (1) Add 0.5 g of sodium dodecylbenzenesulfonate, 50 g of deionized water, 100 g of octamethylcyclotetrasiloxane, 2 g of methyltriethoxysilane, and 3 g of γ-methacryloyloxypropyltrimethoxysilane to a beaker in sequence, and emulsify for 3 min using a high shear emulsifier to obtain a silicone pre-emulsion; add 0.4 g of sulfuric acid and 50 g of deionized water to a beaker and stir to mix uniformly to obtain an acid catalyst solution.

[0049] (2) Add 0.2 g of sodium dodecylbenzenesulfonate and 20 g of deionized water to a four-necked flask equipped with a reflux condenser and a mechanical stirrer under a constant temperature water bath, stir and heat to 50° C., add 2% of the organosilicon pre-emulsion and 5% of the acid catalyst prepared in step (1), heat to 70° C. and react for 60 min, then add the remaining organosilicon pre-emulsion and acid catalyst dropwise within 2 h, heat to 75° C. and react at a constant temperature for 5 h, adjust the pH to 8 with ammonia water and filter to obtain a nano-silicone rubber core particle emulsion with a solid content of 44% and an average particle size of 290 nm.

[0050] (3) Add 0.5 g of sodium dodecylbenzenesulfonate, 15 g of deionized water, and 48 g of methyl methacrylate to a beaker in sequence, and emulsify with a high shear emulsifier for 3 min to obtain a methyl methacrylate emulsion; add 0.1 g of sodium dodecylbenzenesulfonate, 2.4 g of deionized water, and 4.8 g of 4-ethyleneaniline to a beaker in sequence, and emulsify with a high shear emulsifier for 3 min to obtain a 4-ethyleneaniline emulsion; add 0.2 g of sodium bicarbonate and 2 g of deionized water to a beaker and stir to mix uniformly to obtain a buffer solution; add 0.1 g of potassium persulfate and 20 g of deionized water to a beaker and stir to mix uniformly to obtain a catalyst solution.

[0051] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, 0.5 g of sodium dodecylbenzenesulfonate, 20 g of deionized water, 100 g of the nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3) were added, and the mixture was stirred and heated to 75°C. Methyl methacrylate pre-emulsion and 95% of the catalyst solution prepared in step (3) were added dropwise within 1.5 h, and the reaction was carried out at a constant temperature for 2 h.

[0052] (5) Cooling to 70°C, adding 4-ethyleneaniline emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 80°C for 1 hour to prepare an active nano-silicone rubber core-shell particle emulsion with a solid content of 44% and an average particle size of 403 nm; (6) Add 100 g of active nano silicone rubber core-shell particle emulsion and 100 g of deionized water into a beaker and mix well. Spray dry at 150 °C to obtain 42.5 g of active nano silicone rubber core-shell particle powder.

[0053] (7) 40 g of active nano silicone rubber core-shell particle powder and 60 g of hydrogenated bisphenol A epoxy resin were melt-blended at 120°C for 30 min to obtain an active nano silicone rubber core-shell particle pre-dispersion liquid. Example

[0054] (1) Add 1 g of sodium docusate, 50 g of deionized water, 100 g of octamethylcyclotetrasiloxane, 10 g of methyltriethoxysilane, and 8 g of γ-methacryloyloxypropyltrimethoxysilane to a beaker in sequence, and emulsify for 6 min using a high shear emulsifier to obtain a silicone pre-emulsion; add 0.8 g of sulfuric acid and 50 g of deionized water to a beaker and stir to mix uniformly to obtain an acid catalyst solution.

[0055] (2) To a four-necked flask equipped with a reflux condenser and a mechanical stirrer, 1 g of sodium docusate and 30 g of deionized water were added, the mixture was stirred and heated to 50° C., 5% of the organosilicon pre-emulsion and 6% of the acid catalyst prepared in step (1) were added, the mixture was heated to 75° C. and reacted for 60 min. The remaining organosilicon pre-emulsion and acid catalyst were added dropwise within 2 h, the mixture was reacted at a constant temperature for 5 h, the pH was adjusted to 8 with ammonia water, and the mixture was filtered to obtain a nano-silicone rubber core particle emulsion with a solid content of 48% and an average particle size of 180 nm.

[0056] (3) 0.5 g of docusate sodium, 15 g of deionized water, and 20 g of styrene were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a styrene emulsion; 0.3 g of docusate sodium, 2.2 g of deionized water, and 4.4 g of hydroxyethyl methacrylate were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a hydroxyethyl methacrylate emulsion; 0.4 g of sodium bicarbonate and 4 g of deionized water were added to a beaker and stirred to obtain a buffer solution; 0.35 g of potassium persulfate and 25 g of deionized water were added to a beaker and stirred to obtain a catalyst solution.

[0057] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, 0.5 g of sodium docusate, 20 g of deionized water, 100 g of the nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3) were added, and the mixture was stirred and heated to 75°C. After the styrene pre-emulsion and 70% of the catalyst solution prepared in step (3) were added dropwise within 1.5 h, the reaction was continued at a constant temperature for 2 h.

[0058] (5) Cooling to 70°C, adding hydroxyethyl methacrylate emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 85°C for 1 hour to prepare an active nano-silicone rubber core-shell particle emulsion with a solid content of 43.1% and an average particle size of 388 nm; (6) Add 100 g of active nano-silicone rubber core-shell structure polymer and 100 g of deionized water into a beaker and mix well. Spray dry at 150 °C to obtain 41.8 g of active nano-silicone rubber core-shell particle powder.

[0059] (7) 33 g of active nano silicone rubber core-shell particle powder and 67 g of hydrogenated bisphenol A epoxy resin were melt-blended at 105 °C for 30 min to obtain an active nano silicone rubber core-shell particle pre-dispersion liquid. Example

[0060] (1) Add 2.5 g of sodium dodecylbenzenesulfonate, 50 g of deionized water, 100 g of octamethylcyclotetrasiloxane, 2 g of methyltriethoxysilane, and 3 g of vinyltrimethoxysilane to a beaker in sequence, and emulsify for 3 min using a high shear emulsifier to obtain a silicone pre-emulsion; add 0.5 g of sulfuric acid and 50 g of deionized water to a beaker and stir to mix uniformly to obtain an acid catalyst solution.

[0061] (2) Add 1 g of sodium dodecylbenzenesulfonate and 20 g of deionized water to a four-necked flask equipped with a reflux condenser and a mechanical stirrer under a constant temperature water bath, stir and heat to 55°C, add 10% of the organosilicon pre-emulsion and 15% of the acid catalyst prepared in step (1), heat to 75°C and react for 60 minutes, then add the remaining organosilicon pre-emulsion and acid catalyst dropwise within 2 hours, react at a constant temperature for 5 hours, adjust the pH to 7 with ammonia water, and filter to obtain a nano-silicone rubber core particle emulsion with a solid content of 46.1% and an average particle size of 102 nm.

[0062] (3) 0.38 g of sodium dodecylbenzenesulfonate, 15 g of deionized water, and 18 g of methyl methacrylate were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain a methyl methacrylate emulsion; 0.04 g of sodium dodecylbenzenesulfonate, 1 g of deionized water, and 2 g of acrylic acid were added to a beaker in sequence, and the mixture was emulsified using a high shear emulsifier for 3 min to obtain an acrylic acid emulsion; 0.1 g of sodium bicarbonate and 1 g of deionized water were added to a beaker and stirred to obtain a buffer solution; 0.1 g of potassium persulfate and 20 g of deionized water were added to a beaker and stirred to obtain a catalyst solution.

[0063] (4) To a four-necked flask equipped with a constant temperature water bath jacket and a reflux condenser and a mechanical stirrer, 0.2 g of sodium dodecylbenzenesulfonate, 20 g of deionized water, 100 g of the nano-silicone rubber core particle emulsion, and the buffer solution prepared in step (3) were added, and the mixture was stirred and heated to 75°C. Methyl methacrylate pre-emulsion and 80% of the catalyst solution prepared in step (3) were added dropwise within 2 h, and the reaction was carried out at a constant temperature for 2 h.

[0064] (5) Cooling to 65°C, adding acrylic acid emulsion and the remaining catalyst solution dropwise within 30 minutes, and then heating to 80°C for 1.5 hours to prepare active nano-silicone rubber core-shell particle emulsion with a solid content of 45.2% and an average particle size of 150 nm; (6) Add 100 g of active nano-silicone rubber core-shell particle emulsion and 100 g of deionized water into a beaker and mix well. Spray dry at 150 °C to obtain 40 g of active nano-silicone rubber core-shell structure polymer.

[0065] (7) 10 g of active nano silicone rubber core-shell particle powder and 90 g of trimethylolpropane glycidyl ether resin were melt-blended at 100 °C for 50 min to obtain an active nano silicone rubber core-shell particle pre-dispersion liquid.

Claims

1. A method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles, characterized in that: Here are the steps: (1) By weight, 500 parts of organosilicon monomer, 2-50 parts of emulsifier, 10-80 parts of silane coupling agent, 10-80 parts of vinyl silane coupling agent, and 250-400 parts of water are emulsified in a high shear emulsifier for 3 minutes to 10 minutes to obtain an organosilicon pre-emulsion; 2-30 parts of acid catalyst and 200-250 parts of water are mixed uniformly to obtain an acid catalyst solution; (2) By weight, 1-25 parts of emulsifier and 40-160 parts of water are mechanically stirred and heated to 40°C-70°C, 1%-20% of the organosilicon pre-emulsion and 5%-40% of the acid catalyst prepared in step (1) are added, the temperature is raised to 70°C-95°C and the reaction is carried out for 15min-60min, the remaining organosilicon pre-emulsion and acid catalyst are added dropwise within 1h-4h, the reaction is carried out at a constant temperature for 2h-6h, the pH is adjusted to 5-9 with ammonia water, and the nano-silicone rubber core particle emulsion is obtained by filtration; (3) By weight, 5-50 parts of double bond-containing monomer, 0.01-5 parts of emulsifier, and 3-30 parts of water are emulsified in a high shear emulsifier for 3 min-10 min to obtain a double bond-containing pre-emulsion; 1-25 parts of functional monomer, 0.01-5 parts of emulsifier, and 1-30 parts of water are emulsified in a high shear emulsifier for 3 min-10 min to obtain a functional monomer emulsion; 0-1 parts of buffer and 0-10 parts of water are stirred and dissolved to obtain a buffer solution; 0.01-5 parts of catalyst and 1-200 parts of water are stirred and dissolved to obtain a catalytic solution; (4) By weight, 100 parts of nano silicone rubber core particle emulsion, 0.01-5 parts of emulsifier, 0-50 parts of water and the buffer solution prepared in step (3) are stirred and heated to 40-90°C, and the double bond-containing pre-emulsion prepared in step (3) and part of the catalyst solution are added dropwise within 1 hour to 4 hours, and the reaction is carried out at a constant temperature for 1 hour to 6 hours to prepare a nano silicone rubber core-shell particle emulsion; (5) Cooling to 30-80°C, adding the functional monomer emulsion prepared in step (3) and the remaining catalyst solution to the nano-silicone rubber core-shell particle emulsion within 1-60 minutes, heating to 40-90°C and reacting for 1-6 hours to prepare an active nano-silicone rubber core-shell particle emulsion; (6) By weight, 100 parts of active nano silicone rubber core-shell particle emulsion and 50-300 parts of water are mixed evenly, and spray dried at 120°C-220°C to obtain active nano silicone rubber core-shell particle powder; (7) Add 10-75 parts by weight of the prepared active nano silicone rubber core-shell particle powder to 100 parts of epoxy resin, and melt-blend at 50°C-180°C for 0.5h-12h to prepare a pre-dispersion of active nano silicone rubber core-shell particles.

2. The method for preparing the active nano silicone rubber core-shell particle pre-dispersion liquid according to claim 1, characterized in that: The organosilicon monomer described in step (1) is one of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and low molecular weight hydroxy silicone oil.

3. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The emulsifier described in steps (1) to (4) is one of sodium docusate, sodium dodecyl sulfonate, sodium dodecylbenzenesulfonate, dodecylbenzenesulfonic acid, sodium didodecylphenyl ether disulfonate, sodium rosinate, sodium cyclohexane, sodium ricinoleate, isomeric tridecyl alcohol ether, polyoxyethylene octylphenol ether-10, sorbitan monolaurate, sorbitan monopalmitate, or a combination thereof.

4. The method for preparing a pre-dispersion liquid of active nano-silicone rubber core-shell particles of active nano-silicone rubber core-shell structure according to claim 1, characterized in that: The silane coupling agent in step (1) is one of methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltrimethoxysilane, tetraethyl silicate or a combination thereof; The vinyl silane coupling agent in step (1) is one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane or a combination thereof.

5. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The acid catalyst in step (1) is one of benzenesulfonic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, hydrochloric acid, sulfuric acid or a combination thereof.

6. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The double bond-containing monomer in step (3) is one of styrene, methyl methacrylate, butyl acrylate, isooctyl acrylate, acrylic acid, and lauryl methacrylate, or a combination thereof.

7. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The functional monomer in step (3) is one or a combination of functional monomers containing epoxy groups, amino groups, and carboxyl groups.

8. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 7, characterized in that: The epoxy-containing functional monomer is glycidyl methacrylate or allyl glycidyl ether; the amino-containing functional monomer is one of allylamine, 4-vinylaniline, and 4-pentene-1-amine, or a combination thereof; the hydroxyl-containing functional monomer is one of hydroxyethyl methacrylate, hydroxypropyl methacrylate, and 1-pentene-3-ol, or a combination thereof; and the carboxyl-containing functional monomer is one of acrylic acid, methacrylic acid, methylenesuccinic acid, maleic acid, and crotonic acid, or a combination thereof.

9. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The buffering agent in step (3) is one of sodium bicarbonate, sodium formate, sodium acetate, ammonium acetate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium pyrophosphate, sodium phosphate, or a combination thereof; The catalyst in step (3) is one of ammonium persulfate and potassium persulfate.

10. The method for preparing a pre-dispersion liquid of active nano silicone rubber core-shell particles according to claim 1, characterized in that: The epoxy resin described in step (7) is one or a combination of bisphenol A epoxy resin, bisphenol F epoxy resin, polyphenol glycidyl ether epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, epoxidized olefin compound, heterocyclic and mixed epoxy resin.

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