A miniemulsion polymer, its preparation and use

Abstract

The application provides a miniemulsion polymer, which is prepared by a miniemulsion polymerization method through controlling pre-emulsion droplet particle size by a high-pressure homogenizer, using specific auxiliary stabilizers and specific primary emulsifiers. After the miniemulsion polymer is incorporated into a base material, an engineering material with high air tightness, high water tightness, high bonding strength and excellent durability can be obtained, which is used for the durability protection or sealing of engineering structures or the bonding between different materials, and has the advantages of simple process, low cost and outstanding comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of engineering materials, and more particularly to a fine emulsion polymer, its preparation method, and its application in the field of engineering materials. Background Technology

[0002] With the increasing demands for sealing, durability, and cross-material bonding performance in ultra-low energy buildings, medical buildings, and underground / hydraulic engineering structures, waterborne polymers have attracted widespread attention as low-VOC, construction-friendly adhesive / sealing / protective substrates. However, traditional emulsion polymerization systems typically rely on small-molecule surfactants to maintain latex stability. Residual surfactants tend to migrate to the film / interface after film formation, leading to decreased water resistance, adhesion, and durability. This problem is particularly prominent under long-term exposure or humid environments. To mitigate these effects, researchers have proposed a "reactive surfactant / polymerizable surfactant" strategy, which allows surfactants to covalently bind to the particle surface or polymer segments during polymerization, thereby inhibiting migration and improving the water resistance and interfacial stability of the coating.

[0003] To balance polymer performance and formulation designability, miniemulsion polymerization has proven to be an effective approach. This method uses mechanical energy (such as high-pressure homogenization) to stably disperse monomer-containing nanoscale droplets in an aqueous phase. The droplets act as both "nanoreactors" and determine the final particle size distribution, enabling efficient encapsulation and controlled polymerization of hydrophobic monomers / functional molecules, and significantly expanding the chemical space that emulsion polymerization can process.

[0004] Within the scope of the search of publicly available literature, no complete solution has yet been found for an aqueous microemulsion polymer system that simultaneously possesses high airtightness, high watertightness, high bond strength, and durability for engineering structures. This gap limits the further development of the application of aqueous systems in sealing complex joints, cross-material bonding, and long-term exposure protection.

[0005] Therefore, there is an urgent need in this field for a novel fine emulsion polymer and its preparation method that are synergistically designed in emulsification, polymerization and interface chemistry, so as to meet the comprehensive requirements of engineering structures for air tightness / water tightness / durability / adhesion while satisfying green construction and low VOC. Summary of the Invention

[0006] The purpose of this invention is to provide a fine emulsion polymer.

[0007] Another object of the present invention is to provide a method for preparing a fine emulsion polymer.

[0008] Another object of the present invention is to provide an application of a fine emulsion polymer as a high-performance composite material in engineering structures.

[0009] In a first aspect of the present invention, a method for preparing a fine emulsion polymer is provided, comprising the following steps: (s1) Mix the monomer and the auxiliary stabilizer, and then add the main emulsifier solution to obtain a pre-emulsion; The stabilizer is N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, and the emulsifier is an EO-PO-EO block copolymer. (s2) The pre-emulsion obtained in step (s1) is homogenized and mixed to obtain a pre-emulsion; (s3) The pre-emulsion obtained in step (s2) is mixed with an initiator and subjected to a fine emulsion polymerization reaction to obtain the fine emulsion polymer.

[0010] In another preferred embodiment, the monomer comprises octyl acrylate and styrene.

[0011] In another preferred embodiment, the weight ratio of octyl acrylate to styrene is 3:7 to 7:3, for example, 4:6, 1:1, or 6:4.

[0012] In another preferred embodiment, the structure of the stabilizer is shown below: .

[0013] In another preferred embodiment, the amount of the stabilizer added is 0.5-10% of the total weight of the monomers, preferably 1-10%, more preferably 2-8%, for example 1%, 3%, or 5%.

[0014] In another preferred embodiment, the primary emulsifier is Pluronic® F127.

[0015] In another preferred embodiment, the primary emulsifier is PEO. 100 -PPO 65 -PEO 100 .

[0016] In another preferred embodiment, the molecular weight of the primary emulsifier is 5000-15000 Da, preferably 8000-14000 Da, more preferably 10000-13000 Da, for example 12600 Da.

[0017] In another preferred embodiment, the HLB value of the primary emulsifier is ≥18, more preferably ≥20, for example 22.

[0018] In another preferred embodiment, the amount of the main emulsifier added is 1-10% of the total weight of the monomers, more preferably 2-8%, for example 1%, 3%, or 5%.

[0019] In another preferred embodiment, the primary emulsifier solution is an aqueous solution of the primary emulsifier, such as a deionized aqueous solution.

[0020] In another preferred embodiment, step (s1) includes: mixing the monomer and the co-stabilizer, and adding an aqueous solution of the main emulsifier while stirring to obtain a pre-emulsion.

[0021] In another preferred embodiment, in step (s2), the homogenization mixing refers to mixing in a high-pressure homogenizer for 2-8 cycles (preferably 2-5 cycles).

[0022] In another preferred embodiment, in step (s2), the homogenization is carried out at 20-300 MPa, preferably 50-200 MPa, for example 50 MPa, 100 MPa, or 150 MPa.

[0023] In another preferred embodiment, the median particle size D of the droplets in the preemulsion is... 50 The range is between 300-1000 nm, preferably between 400-800 nm, such as 500 nm, 600 nm, and 700 nm.

[0024] In another preferred embodiment, the droplet size distribution index (PDI) in the preemulsion is ≤0.18, preferably ≤0.15, for example 0.13, 0.12, 0.11, 0.1.

[0025] In another preferred embodiment, step (s2) includes: mixing the pre-emulsion obtained in step (s1) 2-8 times under high pressure homogenization at 20-300 MPa to obtain a pre-emulsion.

[0026] In another preferred embodiment, the initiator is a peroxide initiator, preferably selected from the group consisting of sodium persulfate, ammonium persulfate, potassium persulfate, or combinations thereof.

[0027] In another preferred embodiment, the amount of the initiator added is 0.01-1% of the total weight of the monomer, more preferably 0.05-0.8%, more preferably 0.1-0.5%, for example 0.2%, 0.25%, 0.3%, 0.4%.

[0028] In another preferred embodiment, in step (s3), the initiator is added in two batches.

[0029] In another preferred embodiment, the weight ratio of the first batch of added initiator to the second batch of added initiator is 2:1 to 1:2, preferably 1:1 to 1:2.

[0030] In another preferred embodiment, step (s3) includes: mixing the pre-emulsion obtained in step (s2) with the first batch of initiator, reacting for T1, and then adding the second batch of initiator dropwise, reacting for T2, to obtain the fine emulsion polymer.

[0031] In another preferred embodiment, in step (s3), the microemulsion polymerization reaction is carried out at 60-90°C, preferably 70-80°C, for example 75°C.

[0032] In another preferred embodiment, in step (s3), the microemulsion polymerization reaction is carried out in a protective atmosphere.

[0033] In another preferred embodiment, the protective gas is selected from the group consisting of nitrogen, helium, and neon.

[0034] In another preferred embodiment, T1 is 2-20 minutes, preferably 5-20 minutes, for example 10 minutes or 15 minutes.

[0035] In another preferred embodiment, T2 is 4-10 hours, preferably 4-8 hours, such as 5 hours, 6 hours, or 7 hours.

[0036] In another preferred embodiment, step (s3) includes: mixing the pre-emulsion obtained in step (s2) with the first batch of initiators under a protective atmosphere at 60-90°C, reacting for 2-20 minutes, and then adding the second batch of initiators dropwise, reacting for 4-10 hours to obtain the fine emulsion polymer.

[0037] In another preferred embodiment, the fine emulsion polymer obtained in step (s3) is in the form of a polymer emulsion.

[0038] In a second aspect of the invention, a fine emulsion polymer is provided, which is prepared using the method described in the first aspect of the invention.

[0039] In another preferred embodiment, the fine emulsion polymer is in the form of an emulsion.

[0040] In another preferred embodiment, the microemulsion polymer is a non-toxic polymer.

[0041] In another preferred embodiment, the fine emulsion polymer is non-corrosive.

[0042] In another preferred embodiment, the fine emulsion polymer is an aqueous polymer.

[0043] In another preferred embodiment, the number-average molecular weight (Mn) of the fine emulsion polymer is 20,000-200,000, preferably 50,000-150,000.

[0044] In another preferred embodiment, the solid content of the fine emulsion polymer is 30%-50%, preferably 40%-45%.

[0045] In another preferred embodiment, the glass transition temperature of the fine emulsion polymer is -20 to 30°C, preferably -10 to 20°C.

[0046] In a third aspect of the invention, an engineering material premix is ​​provided, comprising the following components in parts by weight: - 100 copies of substrate; - 5-40 parts of the fine emulsion polymer (based on solid content) as described in the first aspect of the present invention; - 20-50 parts of powder filler; - 5-50 parts water.

[0047] In another preferred embodiment, the substrate is selected from one or more of cement, concrete, asphalt, geopolymer, desulfurized gypsum, and phosphogypsum.

[0048] In another preferred embodiment, the powder filler is at least one of quartz powder, silica fume, slag powder, fly ash, and waste incineration ash.

[0049] In another preferred embodiment, the engineering material premix may optionally include other additives acceptable in the fields of construction, municipal engineering, water conservancy, energy, and automotive engineering.

[0050] In another preferred embodiment, the other engineering-acceptable additives include, but are not limited to, weathering agents, curing agents, plasticizers, fillers, antioxidants, UV stabilizers, mildew inhibitors, bactericides, colorants, diluents, flame retardants, defoamers, preservatives, (photo)catalysts, repair agents, and carbon fixatives.

[0051] In a fourth aspect of the invention, an engineering material is provided, which is obtained by curing the engineering material premix described in the third aspect of the invention after optional casting.

[0052] In another preferred embodiment, the curing is carried out at room temperature, more preferably at 5 to 35°C.

[0053] In another preferred embodiment, the engineering material is a protective layer.

[0054] In another preferred embodiment, the protective layer is obtained by casting the engineering material premix described in the third aspect of the present invention.

[0055] In another preferred embodiment, the thickness of the protective layer is 1-200 mm.

[0056] In another preferred embodiment, the engineering material is a sealing material.

[0057] In another preferred embodiment, the sealing material is obtained by applying the engineering material premix described in the third aspect of the present invention to the part that needs to be sealed and then curing it.

[0058] In another preferred embodiment, the engineering material is a durable material, which includes UV-resistant materials and / or anti-aging materials.

[0059] In another preferred embodiment, the engineering material is a connecting material used to connect components of different materials.

[0060] In another preferred embodiment, the connecting material is obtained by applying the engineering material premix described in the third aspect of the invention between the two components to be connected and then curing it.

[0061] In another preferred embodiment, the two components have the same or different media.

[0062] In another preferred embodiment, the 28-day compressive strength of the engineering material is ≥50MPa.

[0063] In another preferred embodiment, the 28-day flexural strength of the engineering material is ≥10 MPa.

[0064] In another preferred embodiment, the 28-day tensile strength of the engineering material is ≥6.5 MPa.

[0065] In another preferred embodiment, the permeability coefficient of the engineering material is ≤ 5.0 × 10⁻⁶. -18 m / s.

[0066] In another preferred embodiment, the air tightness of the engineering material reaches level 6 or above, preferably level 7, according to GB / T 7106-2019.

[0067] In another preferred embodiment, the water tightness of the engineering material reaches level 3 or above, preferably level 5, according to GB / T 7106-2019.

[0068] In another preferred embodiment, according to GB / T 7124-2008, the bonding strength of the engineering material is ≥2.0 MPa, preferably ≥2.5 MPa.

[0069] In another preferred embodiment, a tensile test is performed according to GB / T 528-2009 (Type 2 dumbbell, 500±50 mm / min), and the tensile strength of the engineering material is ≥3.0 MPa, preferably ≥3.5 MPa.

[0070] In another preferred embodiment, the engineering material undergoes an accelerated aging test according to GB / T 16422.1, and the tensile strength retention rate after 1000 hours of accelerated aging under ultraviolet irradiation exceeds 90%, preferably exceeding 92%.

[0071] In a fifth aspect of the invention, an article is provided comprising the fine emulsion polymer described in the second aspect of the invention, and optionally other engineering-acceptable additives.

[0072] In a sixth aspect of the invention, the use of fine emulsion polymers as described in the second aspect of the invention, or engineering material premixes as described in the third aspect of the invention, or engineering materials as described in the fourth aspect of the invention, or articles as described in the fifth aspect of the invention, in engineering structures as (a) a durable agent; and / or (b) a sealing material; and / or (c) a connecting material for components of different materials.

[0073] In another preferred embodiment, the engineering structure includes residential roofs, rooftops, medical buildings, water conservancy facilities, underground works, glass curtain walls or skylights, automotive engineering, etc.

[0074] In another preferred embodiment, the components of different materials include base materials such as concrete, steel plate, glass, plastic, ceramic, and rubber.

[0075] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Attached Figure Description

[0076] Figure 1 The tensile shear strength results for different substrates are shown.

[0077] Figure 2 The tensile properties are shown in the figure. The left figure is the tensile stress-strain curve (type 2 dumbbell), and the right figure is the data consistency results.

[0078] Figure 3 The results of the aging resistance are shown. The left figure shows the evolution of mechanical properties during UV aging, and the right figure shows the performance retention rate and color difference evolution trend. Detailed Implementation

[0079] Through extensive and in-depth research, the inventors have discovered for the first time a polymer emulsion obtained through a microemulsion polymerization reaction. This polymer emulsion exhibits excellent flexibility, excellent flowability, high hydration, and strong viscosity.

[0080] After being mixed with cement, powder (quartz powder, slag powder, etc.) and water, and then vibrated and cured, it can form a protective material or connecting material with high air tightness, high water tightness, high bonding strength and excellent durability. It can be used for the durable protection and sealing of engineering structures or the bonding between different materials. In particular, it can solve the deformation coordination problem when different media materials are bonded together.

[0081] Based on this, the present invention was completed.

[0082] the term Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0083] As used herein, the terms “comprising,” “including,” and “containing” are used interchangeably and include not only closed definitions but also semi-closed and open definitions. In other words, the terms include “consisting of” and “substantially consisting of”.

[0084] As used herein, when referring to a specific enumerated value, the term “about” means that the value can vary by no more than 1% from the enumerated values. For example, as used herein, the expression “about 100” includes all values ​​between 99 and 101 (e.g., 99.1, 99.2, 99.3, 99.4, etc.).

[0085] Fine emulsion polymers As used herein, the terms "polymer of the present invention", "fine emulsion polymer" and "polymer emulsion" are used interchangeably to refer to polymers in emulsion form prepared using the methods of the present invention.

[0086] In this invention, a high-HLB EO-PO-EO block copolymer is used as the main emulsifier, combined with a specific silane monomer (e.g., N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane) that simultaneously possesses the triple functions of "stabilizing / polymerizing / coupling" as a reactive stabilizer / functional monomer. The fine emulsion polymer of this invention is prepared by precisely controlling the droplet size of the pre-emulsion (e.g., D50 about 300–1000 nm, PDI ≤ 0.18) through high-pressure homogenization.

[0087] Preferably, the method for preparing the fine emulsion polymer includes the following steps: (1) The monomer mixture and the auxiliary stabilizer are premixed evenly. Under stirring, the monomer mixture is added to deionized water in which the main emulsifier is dissolved to form a pre-emulsion, wherein: - The main emulsifier is an EO-PO-EO block copolymer with a molecular weight of 8000-14000 Da and an HLB value ≥18; - The stabilizer is N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, and its addition amount is 0.5-5% of the total weight of the monomer mixture; (2) The pre-emulsion obtained in step (1) is subjected to a high-pressure homogenizer and circulated 2-5 times under a pressure of 50-200 MPa. The median particle size (D50) of the droplets in the pre-emulsion is 400-800 nm and the particle size distribution index (PDI) is ≤0.15. (3) Under nitrogen protection, the pre-emulsion is heated to 70-80℃, an initiator solution is added, and a fine emulsion polymerization reaction is carried out for 4-8 hours to obtain a polymer emulsion with a glass transition temperature (Tg) of -10~20℃.

[0088] In the fine emulsion preparation process, high-pressure homogenization (HPH) plays a decisive role in the median droplet size (D50), droplet distribution (PDI), and stability. The coordinated control of parameters such as pressure, number of cycles, and temperature can achieve stable droplets ranging from submicron to hundreds of nanometers in the range of tens to hundreds of MPa, thereby providing a uniform and controllable precursor dispersion system for subsequent polymerization.

[0089] In terms of emulsifying / stabilizing components, EO-PO-EO block copolymers (such as Pluronic® F127) are a class of hydrophilic-hydrophobic-hydrophilic triblock nonionic surfactants that can form micelles in the aqueous phase and stabilize the oil / water interface. Their high HLB and multi-segment structure are beneficial for maintaining interfacial stability and dimensional stability during film formation near substrates such as inorganic fillers, metals or glass.

[0090] On the other hand, silane coupling agents can form durable chemical bridges (such as Si-O-Si bonds) between organic polymers and hydroxyl-rich inorganic substrates, significantly improving adhesion reliability and retention under humid and hot conditions. Numerous studies and engineering practices have confirmed the adhesion-enhancing and interfacial durability mechanisms of silanes on inorganic fillers / glass / mineral substrates.

[0091] The preparation of fine emulsion polymerization requires the use of emulsifiers and co-stabilizers (also called co-emulsifiers). Traditional co-stabilizers include n-hexadecane and n-hexadecyl alcohol. Alternatively, reactive raw materials can be used, which act as co-stabilizers and participate in the polymerization reaction, thereby reducing the residual co-stabilizer in the polymer.

[0092] The silane monomer (N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane) used in this invention not only acts as a stabilizer but also has a crosslinking effect, increasing the degree of crosslinking in the polymer. Simultaneously, it reacts with hydroxyl-containing inorganic materials, enhancing the strength of the interpenetrating structure between the polymer and the inorganic material; therefore, it can also serve as a functional monomer. Such monomers are unusable in conventional emulsion polymerization due to the easy hydrolysis of silanes. In fine emulsion polymerization, after the silane and monomer are mixed, during emulsification at room temperature, the monomer reduces the contact between the silane and water, preventing further silane hydrolysis.

[0093] Preferably, the monomer mixture consists of octyl acrylate and styrene, wherein the weight ratio of octyl acrylate to styrene is 4:6 to 6:4.

[0094] Preferably, the amount of the main emulsifier added is 1-5% of the weight of the monomer mixture.

[0095] Preferably, the initiator is sodium persulfate, and its addition amount is 0.1-2% of the weight of the monomer mixture.

[0096] Preferably, the number average molecular weight (Mn) of the obtained fine emulsion polymer is 50,000-150,000, and the emulsion solid content is 40-45%.

[0097] Engineering materials In this invention, the term "engineering material" refers to a material used in engineering structures that combines durability, sealing properties, and excellent adhesion properties, obtained by mixing the fine emulsion polymer of this invention with a substrate, powder, and water, and then casting or directly curing it on the application site.

[0098] In this invention, the term "engineering material premix" refers to a premix obtained by adding only fine emulsion polymers, substrates, powders, and water to the aforementioned engineering materials before curing.

[0099] The engineering material of the present invention forms a protective layer after being cast and molded. This protective layer can be used for roofs, roofs and the like to provide durability, especially protection against ultraviolet aging.

[0100] Alternatively, the engineering material of the present invention can be applied as a sealing material to joints or gaps that require sealing, or added as a protective layer between two plates. This sealing material can be used in conventional residential buildings (e.g., steel-structured prefabricated houses), water conservancy projects, underground projects, medical buildings, automotive engineering, and other engineering structures that require anti-aging, sealing, and deformation coordination.

[0101] Alternatively, the engineering material of the present invention can be applied as a connecting material between components of different materials that need to be connected, which can solve the problem of deformation coordination when different media materials are bonded together.

[0102] The main advantages of this invention include: (1) The polymer of the present invention has excellent flexural properties, excellent flowability and high hydration.

[0103] (2) The materials prepared by the polymer of the present invention have excellent air tightness, high compressive strength, high flexural strength and high tensile strength.

[0104] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. In the embodiments, a total weight of 100 parts by weight of octyl acrylate and styrene is used as the basis for calculation. Unless otherwise stated, percentages and parts are weight percentages and parts by weight.

[0105] Material Pluronic® F127 was purchased from BASF, and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane was purchased from Gelest.

[0106] Example 1: A monomer mixture consisting of octyl acrylate (60 parts by weight), styrene (40 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (3 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 50 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 720 nm (PDI = 0.12) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of -9°C was obtained.

[0107] Example 2: A monomer mixture consisting of octyl acrylate (40 parts by weight), styrene (60 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (3 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 50 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 720 nm (PDI = 0.12) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 20°C was obtained.

[0108] Example 3 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution of Pluronic® F127 EO-PO-EO block copolymer (3 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was homogenized twice at 50 MPa to obtain a droplet D50 of 720 nm (PDI = 0.12). Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0109] Example 4 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (5 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 50 MPa to obtain droplet D. 50 A pre-emulsion with a Tg of 620 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0110] Example 5 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (3 parts by weight) under stirring to form a stable pre-emulsion. The mixture was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a Tg of 580 nm (PDI = 0.11) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0111] Example 6 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (3 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 150 MPa to obtain droplet D. 50 A pre-emulsion with a Tg of 510 nm (PDI = 0.13) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0112] Example 7 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (5 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 470 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 7 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0113] Example 8 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (5 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 470 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, the sodium persulfate solution (0.1 parts by weight) was added dropwise over 5 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0114] Example 9 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (1 part by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (5 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 470 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, a sodium persulfate solution (0.15 parts by weight) was added dropwise over 6 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0115] Example 10 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (3 parts by weight) was added to a deionized aqueous solution containing Pluronic® F127 EO-PO-EO block copolymer (5 parts by weight) under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 470 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, a sodium persulfate solution (0.15 parts by weight) was added dropwise over 6 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0116] Example 11 A monomer mixture consisting of octyl acrylate (50 parts by weight), styrene (50 parts by weight), and N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane (5 parts by weight) was added to a deionized aqueous solution containing 5 parts by weight of Pluronic® F127 EO-PO-EO block copolymer under stirring to form a stable pre-emulsion. The pre-emulsion was then processed twice under a high-pressure homogenizer at 100 MPa to obtain droplet D. 50 A pre-emulsion with a PDI of 470 nm (PDI = 0.09) was obtained. Subsequently, under nitrogen protection at 75°C, a sodium persulfate solution (0.1 parts by weight) was added to the reactor. After 10 minutes, a sodium persulfate solution (0.15 parts by weight) was added dropwise over 6 hours. A polymer emulsion (40% solids content) with a Tg of 7°C was obtained.

[0117] Example 12 Air tightness test The polymer emulsions in Examples 1-11 were mixed with cement, powder fillers, and water to prepare a sealant, which was used to verify its airtightness. The standard used was GB / T31433-2015.

[0118] 1. Specimen Description A high-performance aluminum alloy casement window, wherein the sealing system of the glass and frame, and the sash and frame, uses a sealant containing the polymer emulsion of the present invention.

[0119] 2. Quantitative performance (based on test results from GB / T 7106-2019) A representative window specimen (area 1.8m²) equipped with this sealing system 2 In the test (with an opening seam length of 5.6m), its quantitative indicators performed as follows: Air permeation per unit seam length ( q 1 After pressure pulse preprocessing and linear regression calculation under a 10Pa pressure difference, the measured value was 0.74m. 3 / (m·h) Air infiltration rate per unit area ( q 2 The measured converted value is 2.3 m. 3 / (m 2 ·h).

[0120] Air tightness rating: According to the grading standard of "General Technical Conditions for Building Curtain Walls, Doors and Windows" (GB / T 31433-2015), the air tightness performance of this system is clearly determined to be level 7.

[0121] Example 13 Water tightness The polymer emulsions in Examples 1-11 were mixed with cement, powder fillers, and water to prepare a sealant, which was used to verify its airtightness. The standard used was GB / T 7106.

[0122] 1. Experimental preparation and apparatus Test specimen description: A high-performance aluminum alloy casement window with an area of ​​A = 2.4m² was used, equipped with this sealant. 2 .

[0123] Testing environment: Indoor temperature 20℃, relative humidity 50%.

[0124] Sprinkler system: Sprinkler flow rate set at the standard requirement of 3.0 L / m 2 ·min.

[0125] 2. Test Procedure: Fluctuating Pressure Method (according to Clause 8.4 of GB / T 7106) To demonstrate the material's stability under extreme weather conditions, this experiment employed a more stringent fluctuating pressure method.

[0126] Preparatory pressurization: Apply three pressure pulses with an absolute pressure difference of 500 Pa.

[0127] Fluctuation detection: Water spraying stage: Start the water spraying system to spray the specimen evenly for 10 minutes.

[0128] Staged pressurization: Pressurize step by step according to the pressurization sequence diagram in Figure 5 and the pressurization sequence table in Table 2 of GB / T 7106, Clause 8.4.

[0129] Fluctuation parameters: The duration of the fluctuating pressure is 15 minutes or until leakage occurs. The fluctuation amplitude is 0.5 times the average value, and the period is 3-5 seconds.

[0130] Leakage observation: Technicians continuously observe the inside of the test specimen and record whether water droplets fall or there is continuous seepage.

[0131] 3. Experimental Results and Numerical Calculations (1) Experimental Record Sheet The order of pressure fluctuations and leakage status are shown in Table 1 below.

[0132] Table 1 (2) Calculation and judgment (based on GB / T 7106, Clause 8.5.1) According to the grading principle of GB / T 7106-2019, the pressure difference of the previous level of leakage pressure difference shall be used as the test value of water tightness performance.

[0133] (3) Grading determination (refer to Table 16 of GB / T 31433-2015) The water tightness results of the sealant containing the polymer emulsion of the present invention are shown in Table 2 below.

[0134] Table 2 4. Conclusion: Engineering Value Evaluation of Sealants The test results show that the performance has been significantly improved: In this test, the structural components using sealant successfully passed the fluctuating pressure test with an average value of 500 Pa (peak value of 750 Pa) and were ultimately rated as level 5.

[0135] Significance of the project: The rating result far exceeds the Class 3 standard required for general projects, proving that the sealant can meet the extreme water tightness requirements of typhoon-prone areas or high-rise buildings, making it an ideal choice for high-quality construction projects.

[0136] Example 14 Adhesion performance The polymer emulsions in Examples 1-11 are mixed with cement, powder fillers, and water to prepare engineering materials for bonding steel plates, glass, concrete, etc.

[0137] 1. Detailed description of the experimental procedure (1) Tensile shear test of rigid materials (steel plate, glass) – according to GB / T 7124 (ISO 4587) This test aims to simulate the ability of the bonded interface to resist shear failure when a structural member is subjected to axial load.

[0138] Specimen preparation: according to GB / T 7124 Figure 1 The design drawings specify the shape and size of the sample. Specifically, a standard steel plate with a specification of 100mm×25mm×1.6mm and tempered glass of the same thickness are selected.

[0139] Surface treatment: The steel plate surface is sandblasted and degreased with acetone; the glass substrate is cleaned and dried according to standards to ensure that no contaminants affect the interface wetting.

[0140] Overlap method: A single overlap is used, with an overlap length set at 12.5mm ± 0.25mm. The bonding area A = 12.5 × 25 = 312.5mm². 2 .

[0141] Loading conditions: Use a tensile testing machine equipped with constant rate control, and adjust the loading rate to a shear stress change rate of 8.3 MPa / min ~ 9.8 MPa / min.

[0142] Test environment: temperature (23±2)℃, relative humidity (50±5)%.

[0143] (2) Tensile bond properties test of concrete substrate – in accordance with GB / T 13477.8 (ISO 8339) Specimen preparation: Substrate: prepared according to GB / T 13477.8 Figure 1 The design drawings specify the shape and size of the test specimen. Specifically, two parallel standard cement mortar / concrete substrate blocks with dimensions of 75mm × 62mm × 12mm are used.

[0144] Filling dimensions: Inorganic adhesive is embedded between two substrates to form an adhesive body with a cross-section of 12mm × 12mm and a length of 50mm. The calculated bonding area S = 12 × 50 = 600 mm². 2 .

[0145] Loading conditions: The tensile testing machine was used to stretch the specimen at a speed of (5.5±0.7) mm / min at (23±2)℃ until the specimen failed.

[0146] 2. Experimental Results and Numerical Calculations Based on the failure load measured in the experiment, the bond strength index of each substrate is calculated.

[0147] (1) Quantitative calculation process Shear strength of steel plate (τ): Failure load F = 1193.75 N Glass shear strength (τ): failure load F = 1065.63 N Maximum tensile strength of concrete (T) s Maximum tensile force P = 1890 N (2) Summary table of test data The results are shown in Table 3 and Figure 1 As shown.

[0148] Table 3 Example 15 Tensile Properties The polymer emulsions in Examples 1-11 were mixed with cement, powder fillers, and water to form engineering materials, which were then cured to form specimens of fixed size and shape for testing their tensile properties, in accordance with the standard GB / T 528-2009.

[0149] 1. Experimental Procedure Sample preparation: Sample type: Type 2 dumbbell-shaped sample.

[0150] Specifications: The width (W) of the narrow part of the sample is 4.0 mm, the gauge length (L0) is 20 mm, and the thickness (t) is adjusted to (2.0±0.2) mm.

[0151] Environmental conditioning: The sample shall be conditioned at a standard laboratory temperature of (23±2)℃ for no less than 16 hours.

[0152] Testing steps: The cross-sectional area of ​​the narrow section of the sample (S=W⋅t) is accurately measured using a thickness gauge.

[0153] The specimen is symmetrically clamped on the tensile testing machine fixture, and the tensile speed is set to 500 mm / min.

[0154] Start the instrument until the sample breaks, and record the maximum force (F) at the moment of fracture. b and the displacement length between gauge lengths (L) b ).

[0155] 2. Experimental Results The results are shown in Table 4 and Figure 2 As shown: Table 4 Example 16 Aging Resistance The polymer emulsions in Examples 1-11 were mixed with cement, powder fillers, and water to prepare engineering materials, which were then cured and used to test their aging resistance.

[0156] 1. Review and continuation of experimental conditions Test standards: GB / T 16422.1 and GB / T 16422.3.

[0157] Light source and circulation: A UVA-340 (Type 1A) fluorescent ultraviolet lamp was used, with 8 hours of irradiation (60℃, 0.76W / (m²)). 2 The process alternates between ⋅nm) and 4h condensation (50℃).

[0158] Testing indicators: Tensile strength, elongation at break, and color difference ΔE are tested according to ISO 4582. * and surface morphology.

[0159] 2. Experimental Results The results are shown in Table 5 below. Figure 3 As shown, the engineering materials modified with the polymer emulsion of the present invention have excellent aging resistance, and their strength remains above 93% even after an ultra-long period of 10,000 hours.

[0160] Table 5 As can be seen, the polymer emulsion in this invention has excellent air tightness, water tightness, bonding strength, tensile strength, and durability. It can also adapt to various construction environments, can be directly coated or plastered, and is non-toxic and non-corrosive. Therefore, it can be used for a variety of building structures, especially for protective layers of building structures with high requirements for air tightness, water tightness, and durability, such as infectious disease hospital wards, underground projects, water conservancy facilities, and photovoltaic roofs.

[0161] Example 17 The polymer emulsion from any of Examples 1-11 was mixed with cement, powder filler, and water to prepare building materials, which were then used in the following applications: 1. Roof perforation sealing When applied to roof sealing (such as the roof of photovoltaic projects), its air tightness and water tightness are superior to conventional organic sealants after actual use, and its durability (UV aging) performance is outstanding.

[0162] 2. Sealing of airtight panels in medical buildings It is used for sealing the joints of medical building panels (such as wards of infectious disease hospitals), and after special airtightness testing, it meets the ultra-high airtightness standards for medical buildings.

[0163] 2. Residential board seam sealing ALC panels, concrete, steel structures, and other substrates used in residential buildings (such as prefabricated high-rise residential buildings) all exhibit pull-out bond strengths exceeding 1.0 MPa, and the joints are reliably leak-proof.

[0164] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for preparing a fine emulsion polymer, comprising the following steps: (s1) Mix the monomer and the auxiliary stabilizer, and then add the main emulsifier solution to obtain a pre-emulsion; The stabilizer is N-(3-methacryloyloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, and the emulsifier is an EO-PO-EO block copolymer. (s2) The pre-emulsion obtained in step (s1) is homogenized and mixed to obtain a pre-emulsion; (s3) The pre-emulsion obtained in step (s2) is mixed with an initiator and subjected to a fine emulsion polymerization reaction to obtain the fine emulsion polymer.

2. The preparation method according to claim 1, characterized in that, The monomer comprises octyl acrylate and styrene; preferably, The weight ratio of octyl acrylate to styrene is 3:7 to 7:

3.

3. The preparation method according to claim 1, characterized in that, The amount of the stabilizer added is 0.5-10% of the total weight of the monomers, preferably 1-10%, and more preferably 2-8%.

4. The preparation method according to claim 1, characterized in that, The amount of the main emulsifier added is 1-10% of the total weight of the monomers, more preferably 2-8%.

5. The preparation method according to claim 1, characterized in that, The initiator is a peroxide initiator, preferably selected from the group consisting of sodium persulfate, ammonium persulfate, potassium persulfate, or combinations thereof; and / or The amount of the initiator added is 0.01-1% of the total weight of the monomer, more preferably 0.05-0.8%, and even more preferably 0.1-0.5%.

6. The preparation method according to claim 1, characterized in that, The median particle size D of the droplets in the preemulsion 50 Between 300-1000 nm, preferably between 400-800 nm; and / or The droplet size distribution index (PDI) in the preemulsion is ≤0.18, preferably ≤0.

15.

7. A fine emulsion polymer prepared using the method described in any one of claims 1-6.

8. An engineering material premix comprising the following components in parts by weight: - 100 copies of substrate; - 5-40 parts of the fine emulsion polymer as described in claim 7 (based on solid content); - 20-50 parts of powder filler; - 5-50 parts water.

9. An engineering material obtained by curing the engineering material premix of claim 8 after optional casting.

10. The use of the fine emulsion polymer of claim 7, or the engineering material premix of claim 8, or the engineering material of claim 9 in engineering structures as (a) a durable agent; and / or (b) a sealing material; and / or (c) a connecting material for components of different materials.

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