Non-migration soft porcelain emulsion based on reactive emulsifier as well as preparation method and application of non-migration soft porcelain emulsion

Abstract

The invention belongs to the technical field of polymer emulsion synthesis, and particularly relates to an acrylate emulsion special for soft porcelain, a preparation method of the emulsion and application of the emulsion in the soft porcelain. In an emulsion polymerization system, a phosphate type polymerizable emulsifier and an allyl or methacryloyloxy single-terminated polyoxyethylene ether emulsifier are compounded to replace a traditional micromolecular emulsifier, so that emulsifier molecules are permanently bonded to a polymer molecular chain through covalent bonds; therefore, the defects of surface skinning, mold sticking, water resistance reduction and the like caused by migration of small molecules are thoroughly eliminated, and the anionic reactive emulsifier is selected from phosphate ester. Meanwhile, a star-shaped coupling agent containing a polyoxyethylene ether block structure is designed and synthesized and is added into the acrylate emulsion, so that the problem that water resistance, alkali resistance and weather resistance are difficult to consider at the same time after film formation is solved, and the surface quality, the production yield and the comprehensive performance of a soft porcelain product are remarkably improved.

Description

Technical Field

[0001] This application belongs to the field of polymer emulsion synthesis technology, specifically relating to an acrylic emulsion for soft porcelain, as well as the preparation method of the emulsion and its application in soft porcelain. Background Technology

[0002] Emulsion polymerization typically requires emulsifiers to reduce interfacial tension, allowing oil-soluble monomers to disperse and stabilize in water into an emulsion. Traditional emulsifiers, such as the anionic surfactant sodium dodecyl sulfate (SDS) and the nonionic surfactant alkylphenol polyoxyethylene ether (OP-10), exist on the surface of latex particles through physical adsorption. These small-molecule emulsifiers lack polymerizable unsaturated bonds and do not form chemical bonds with the polymer after the emulsion forms a film, leading to the following defects: 1. Migration: During the high-temperature baking process in flexible ceramic production, these physically adsorbed small-molecule emulsifiers migrate upon heating. Some migrate to the surface of the slurry, resulting in a bright, dense but fragile film that affects subsequent processes and product appearance; others migrate to the interface between the flexible ceramic and the mold, causing sticking to the mold, i.e., difficulty in demolding, increasing the scrap rate; 2. Poor water resistance: After migration, they leave hydrophilic channels in the polymer film or expose their own hydrophilic groups, resulting in poor water resistance and whiteness of the flexible ceramic product, increased water absorption, and a significant decrease in mechanical properties in humid environments. 3. Negative impact on performance: Small molecule emulsifiers, as impurities, can disrupt the continuity and uniformity of polymer films, reducing their cohesive strength, adhesion, and durability.

[0003] To address these issues, the industry typically employs methods such as adding wetting agents, increasing the amount of defoamer, or using release agents. However, these are merely remedies that do not address the root cause and cannot fundamentally eliminate the migration phenomenon. In some cases, they may even introduce new problems.

[0004] Reactive emulsifiers are a special type of surfactant whose molecular structure contains both emulsifying groups (such as sulfonic acid groups and polyoxyethylene ether segments) and polymerizable groups (such as allyl groups, methacryloyloxy groups, and maleic anhydride groups). During emulsion polymerization, their polymerizable groups can participate in copolymerization reactions and permanently bond to the polymer molecular chain through free radical polymerization, becoming part of the polymer and unable to migrate after the emulsion solidifies into a film.

[0005] Theoretically, applying reactive emulsifiers to emulsions specifically for flexible ceramics could solve the migration problem once and for all. However, its practical application faces significant challenges, including: insufficient matching of polymerization rates, as the polymerization rates of reactive emulsifiers differ greatly from those of acrylate monomers, making it difficult for them to efficiently participate in free radical polymerization reactions and integrate into the polymer chain; and completely abandoning traditional emulsifiers, as relying solely on reactive emulsifiers often fails to yield emulsions with suitable particle size, uniform distribution, and long-term storage stability. Furthermore, flexible ceramic emulsions also present the issue of monomer selection. Using styrene monomers to prepare emulsions significantly improves the water and alkali resistance of the film, but correspondingly reduces weather resistance. If the hard monomer methyl methacrylate is used instead of styrene, weather resistance is improved, but the water and alkali resistance of the film decreases. It is necessary to resolve the contradictory problem of simultaneously achieving water resistance, alkali resistance, and weather resistance in flexible ceramic emulsions. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of existing technologies by using a compound of phosphate ester-type polymerizable emulsifiers (anionic reactive emulsifiers) and allyl or methacryloyloxy-terminated polyoxyethylene ether emulsifiers (nonionic reactive emulsifiers) in the polymerization system to replace traditional small molecule emulsifiers. This allows the emulsifier molecules to be permanently bonded to the polymer molecular chain through covalent bonds, thereby completely eliminating defects such as surface skinning, sticking, and decreased water resistance caused by small molecule migration. The anionic reactive emulsifier is selected from phosphate esters. Simultaneously, a star-shaped coupling agent containing a polyoxyethylene ether block structure is designed and synthesized and added to the acrylic emulsion, solving the problem of simultaneously achieving good water resistance, alkali resistance, and weather resistance after film formation, significantly improving the surface quality, production yield, and overall performance of flexible ceramic products.

[0007] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows: In a first aspect, a non-migratory soft porcelain emulsion comprises: an acrylic emulsion and a coupling agent; The raw materials for the acrylate emulsion include: polymerizable monomers, anionic reactive emulsifiers, nonionic reactive emulsifiers, initiators, and deionized water; The polymerizable monomer contains at least one unsaturated double bond that can participate in free radical polymerization. The polymerizable monomer includes: hard monomers, soft monomers and functional monomers. Hard monomers are polymerizable monomers with a glass transition temperature greater than 0°C in homopolymers. Hard monomers provide hardness, strength, wear resistance and rigidity to copolymers. Soft monomers are polymerizable monomers with a glass transition temperature of less than or equal to 0°C for homopolymers. Soft monomers provide flexibility, ductility, impact resistance and adhesion to copolymers. Preferably, the hard monomer is selected from one or more of styrene, vinyl acetate, methyl methacrylate, methyl acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and acrylonitrile; Preferably, the soft monomer is selected from one or more of ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, isooctyl acrylate, and lauryl acrylate.

[0008] Functional monomers are polymerizable monomers containing at least one carboxyl, hydroxyl, amide, or epoxy group, which enhance the adhesion, hydrophilicity, and other functional properties of the copolymer. The functional monomer is selected from one or more combinations of functional monomers containing carboxyl groups, functional monomers containing hydroxyl groups, functional monomers containing amide groups, and functional monomers containing epoxy groups; Preferably, the carboxyl-containing functional monomer is selected from one or more of acrylic acid, methacrylic acid, and itaconic acid; Preferably, the hydroxyl-containing functional monomer is selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate; Preferably, the amide-containing monomer is selected from one or more of acrylamide and methacrylamide; Preferably, the epoxy-containing monomer is selected from one or more of glycidyl acrylate and glycidyl methacrylate; The anionic reactive emulsifier is selected from alkyl phosphate (meth)acrylate, wherein the phosphate group is attached to the end of the alkyl chain of the (meth)acrylate.

[0009] Preferably, the anionic reactive emulsifier is selected from 2-methyl-2-acrylate-2-(phosphonooxy)ethyl ester; The nonionic reactive emulsifier is selected from allyl or methacryloyloxy single-terminated polyoxyethylene ether emulsifiers; Preferably, the nonionic reactive emulsifier is selected from polyoxyethylene ether emulsifiers with a single methacryloxy group at the end; Preferably, the nonionic reactive emulsifier is selected from either polyethylene glycol monoacrylate or polyethylene glycol monomethacrylate. The initiator is selected from ammonium persulfate or potassium persulfate; Preferably, the deionized water meets the Class II or Class I water standard in GB / T 6682-2008; Preferably, the raw materials for the acrylate emulsion also include a pH buffer, wherein the pH buffer is selected from sodium bicarbonate; Preferably, the raw materials for the acrylate emulsion also include a post-elimination initiator, wherein the post-elimination initiator includes tert-butyl hydroperoxide and vitamin C; The coupling agent includes an isocyanate polymer core and linear side arms. The linear side arms include polyoxyethylene segments and saturated alkyl segments. At least three linear side arms are sequentially connected to the isocyanate polymer core, wherein the polyoxyethylene segments are directly connected to the isocyanate polymer core. Preferably, the isocyanate polymer is selected from aliphatic isocyanate polymers; Preferably, the isocyanate polymer is selected from any one of hexamethylene diisocyanate (HDI) trimer, pentamethylene diisocyanate (PDI) trimer, or isophorone diisocyanate (IPDI) trimer; Preferably, the preparation method of the coupling agent includes: reacting an isocyanate polymer with an alkyl alcohol polyoxyethylene ether; Preferably, dibutyltin laurylate is used as a catalyst to catalyze the reaction between isocyanate polymers and alkyl alcohol polyoxyethylene ethers.

[0010] Furthermore, the raw materials for the non-migratory soft porcelain emulsion, by weight, include: 50-70 parts by weight of deionized water, 1-3 parts by weight of anionic reactive emulsifier, 0.1-1 parts by weight of nonionic reactive emulsifier, 15-30 parts by weight of hard monomer, 15-30 parts by weight of soft monomer, 2-8 parts by weight of functional monomer, 2-8 parts by weight of initiator, and 1-5 parts by weight of coupling agent.

[0011] Preferably, the non-migratory soft porcelain emulsion contains, by weight, 2-4 parts of coupling agent. Further preferred is a non-migratory soft porcelain emulsion, the raw materials of which include 2-3 parts by weight of coupling agent; Preferably, the non-migratory soft porcelain emulsion contains, by weight, 0.1-0.5 parts by weight of pH buffer. Preferably, the non-migratory soft porcelain emulsion contains, by weight, 0.5-2 parts by weight of a post-elimination initiator.

[0012] Secondly, the preparation method of the non-migratory soft porcelain emulsion described above includes: pre-emulsification, seed polymerization, dropwise addition, heat preservation and aging, and post-elimination reaction.

[0013] The pre-emulsification includes dispersing 30-40 parts by weight of deionized water, an anionic reactive emulsifier, a nonionic reactive emulsifier, and a polymerizable monomer to form a pre-emulsion. The seed polymerization involves adding 5-15 parts by weight of deionized water and the prescribed amount of pH buffer to the bottom of the reactor, preparing an initiator solution using 5-15 parts by weight of deionized water and the prescribed amount of initiator, heating the bottom liquid to 75-85°C, adding 1-10 wt% of pre-emulsion and 10-30 wt% of initiator solution dropwise, and controlling the temperature at 80-85°C to react and obtain a seed emulsion. The dripping process involves adding the remaining initiator solution and pre-emulsion separately to the seed emulsion, while controlling the temperature at 80-85℃. The heat preservation and ripening process involves maintaining the temperature at 80-90℃ after the addition is completed; The post-elimination reaction is carried out after the heat preservation and curing process, when the temperature is lowered to 60-75℃. 5-15 parts by weight of deionized water and the formulated amount of post-elimination initiator are separately prepared into solutions and added dropwise to the acrylate emulsion to promote the complete reaction of unreacted monomers and improve the conversion rate.

[0014] Thirdly, a coating film is obtained by baking and drying the above-mentioned non-migratory soft porcelain emulsion at 80-130℃.

[0015] Fourthly, the application of the above-mentioned paint film on building decoration materials.

[0016] The beneficial effects of the above-mentioned technical solution proposed in this application are: 1. The core of this emulsion lies in the use of two reactive emulsifiers, including a phosphate ester polymerizable emulsifier and an allyl or methacryloyloxy single-terminated polyoxyethylene ether emulsifier, which are compounded together to perfectly solve the problems of emulsion polymerization process and emulsion storage stability. At the same time, it avoids the use of traditional non-polymerizable emulsifiers and completely eliminates the migration of small molecules of emulsifier after the emulsion forms a film.

[0017] 2. A star-shaped coupling agent containing a polyoxyethylene ether block structure was designed and synthesized and added to an acrylic emulsion. The hydrophilic polyoxyethylene ether segments can form hydrogen bonds with the polar groups -COOH and -OH of the latex particles in the emulsion, thereby improving hydrophobicity and structural integrity after film formation, and thus improving the water resistance, alkali resistance and weather resistance of the film. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. It should be noted that the terminology used herein is only for describing specific implementations and is not intended to limit the exemplary implementations of the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] Unless otherwise specified, the experimental conditions used in the examples are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the examples can be purchased commercially.

[0020] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings: The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0021] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0022] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0023] In this application, the technical features described in an open-ended manner include both closed-ended technical solutions composed of the listed features and open-ended technical solutions containing the listed features.

[0024] In this application, numerical intervals (i.e., numerical ranges) are involved. Unless otherwise specified, the selected numerical distributions within the aforementioned numerical intervals are considered continuous and include the two endpoints (i.e., the minimum and maximum values) of the numerical range, as well as every value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints. In this document, this is equivalent to directly listing every integer. For example, if t is an integer selected from 1 to 10, it means that t is any integer selected from the group of integers consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Furthermore, when multiple ranges are provided to describe features or characteristics, these ranges can be merged. In other words, unless otherwise specified, the ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0025] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0026] Example 1

[0027] Acrylic emulsions, whose raw material formulations include pre-emulsion, bottom liquid and initiator solution; The pre-emulsion includes: 35 parts by weight of deionized water, 1.5 parts by weight of anionic reactive emulsifier 2-methyl-2-acrylate-2-(phosphonooxy)ethyl ester, 0.6 parts by weight of nonionic reactive emulsifier polyethylene glycol (400) methacrylate, 9 parts by weight of methyl methacrylate, 15 parts by weight of styrene, 21 parts by weight of isooctyl acrylate, 2 parts by weight of acrylic acid, 0.5 parts by weight of acrylamide, and 1.5 parts by weight of hydroxyethyl acrylate. Bottom solution: 10 parts by weight of deionized water, 0.15 parts by weight of sodium bicarbonate pH buffer; Initiator solution: 10 parts by weight of deionized water, 1 part by weight of ammonium persulfate initiator; Preparation steps: Pre-emulsification: Add the prescribed amounts of deionized water, 2-methyl-2-acrylate-2-(phosphonooxy)ethyl ester and polyethylene glycol (400) methacrylate to the pre-emulsification tank, turn on the dispersant and stir at 1000 rpm for 10 minutes. Then, add the prescribed amount of polymerizable monomer while stirring, and use a high-speed disperser to shear and disperse at 1500 rpm for 15 minutes to form a stable pre-emulsion.

[0028] Seed polymerization: Add the bottom liquid to the reactor and heat to 80°C. Add 5 wt% pre-emulsion and 20 wt% initiator solution, and control the temperature at 80-82°C for 15 minutes. The emulsion will turn blue.

[0029] Add pre-emulsion and initiator dropwise: Add the remaining pre-emulsion and initiator solution dropwise into the reactor simultaneously and at a uniform rate over 3 hours through two funnels, while maintaining the reactor temperature at 80-82℃.

[0030] Incubation and ripening: After the addition is complete, heat to 85℃, keep warm for 1.5 hours, then cool down; Post-elimination: Cool to 70°C, prepare solutions of 2.5 parts by weight of water, 0.7 parts by weight of tert-butyl hydrogen peroxide, and 2.5 parts by weight of water and 0.3 parts by weight of vitamin C respectively, and add them dropwise to the emulsion to carry out the post-elimination reaction. The dropwise addition time is 0.5 hours, and then keep warm for 0.5 hours and continue to cool to obtain acrylate emulsion.

[0031] For the preparation of the coupling agent, 42.9 g of isomeric tridecyl alcohol polyoxyethylene ether E1306 (hydroxyl value 121.5 mg KOH / g) was dehydrated under vacuum at 105 °C for 1 hour, then cooled to 70 °C. 20 g of HDI trimer Desmodur N 3390 (Covestro, with NCO content 19.5 wt%) and 0.12 g of dibutyltin laurate DBTL were then added. The mixture was heated to 85 °C and reacted for 4 hours. The reaction mixture was monitored by infrared spectroscopy at 2260-2280 cm⁻¹. -1 The reaction ends when the -NCO infrared absorption peak disappears, and the coupling agent is obtained by cooling.

[0032] The acrylic emulsion was cooled to 40°C, 2 parts by weight of coupling agent were added, and the pH of the emulsion system was adjusted to 8.0-8.5 with ammonia. The emulsion was then filtered to obtain a non-migratory soft porcelain emulsion.

[0033] Example 2

[0034] The acrylate emulsion has a raw material formulation that includes a pre-emulsion, a bottom liquid, and an initiator solution. The formulation and preparation method are the same as in Example 1.

[0035] For the preparation of the coupling agent, 39g of isomeric tridecyl alcohol polyoxyethylene ether E1306 (hydroxyl value 121.5mgKOH / g) was dehydrated under vacuum at 105℃ for 1 hour, then cooled to 70℃. Next, 30g of IPDI trimer Desmodur Z4470 (Covestro, with an NCO content of 11.8wt%) and 0.12g of dibutyltin laurate DBTL were added. The mixture was then heated to 85℃ and reacted for 4 hours. The reaction mixture was monitored by infrared spectroscopy at 2260-2280 cm⁻¹. -1 The reaction ends when the -NCO infrared absorption peak disappears, and the coupling agent is obtained by cooling.

[0036] The acrylic emulsion was cooled to 40°C, 3 parts by weight of coupling agent were added, and the pH of the emulsion system was adjusted to 8.0-8.5 with ammonia. The emulsion was then filtered to obtain a non-migratory soft porcelain emulsion.

[0037] Example 3

[0038] Acrylic emulsions, whose raw material formulations include pre-emulsion, bottom liquid and initiator solution; The pre-emulsion includes: 35 parts by weight of deionized water, 1.5 parts by weight of anionic reactive emulsifier 2-methyl-2-acrylate-2-(phosphonooxy)ethyl ester, 0.5 parts by weight of nonionic reactive emulsifier polyethylene glycol (400) methacrylate, 12 parts by weight of methyl methacrylate, 11 parts by weight of styrene, 22 parts by weight of isooctyl acrylate, 2 parts by weight of methacrylic acid, 0.5 parts by weight of acrylamide, and 1.5 parts by weight of hydroxyethyl methacrylate. Bottom solution: 10 parts by weight of deionized water, 0.15 parts by weight of sodium bicarbonate pH buffer; Initiator solution: 10 parts by weight of deionized water, 1 part by weight of ammonium persulfate initiator; Preparation steps: Pre-emulsification: Add the prescribed amounts of deionized water, 2-methyl-2-acrylate-2-(phosphonooxy)ethyl ester and polyethylene glycol (400) methacrylate to the pre-emulsification tank, turn on the dispersant and stir at 1000 rpm for 10 minutes. Then, add the prescribed amount of polymerizable monomer while stirring, and use a high-speed disperser to shear and disperse at 1500 rpm for 15 minutes to form a stable pre-emulsion.

[0039] Seed polymerization: Add the bottom liquid to the reactor and heat to 80°C. Add 5 wt% pre-emulsion and 20 wt% initiator solution, and control the temperature at 80-82°C for 15 minutes. The emulsion will turn blue.

[0040] Add pre-emulsion and initiator dropwise: Add the remaining pre-emulsion and initiator solution dropwise into the reactor simultaneously and at a uniform rate over 3 hours through two funnels, while maintaining the reactor temperature at 80-82℃.

[0041] Incubation and ripening: After the addition is complete, heat to 85℃, keep warm for 1.5 hours, then cool down; Post-elimination: Cool to 70°C, prepare solutions of 2.5 parts by weight of water, 0.7 parts by weight of tert-butyl hydrogen peroxide, and 2.5 parts by weight of water and 0.3 parts by weight of vitamin C respectively, and add them dropwise to the emulsion to carry out the post-elimination reaction. The dropwise addition time is 0.5 hours, and then keep warm for 0.5 hours and continue to cool to obtain acrylate emulsion.

[0042] The coupling agent was prepared by condensing fatty alcohol with ethylene oxide and adding 56.5g of emulsifier O-8 (seaweed, hydroxyl value 92.3mgKOH / g). The mixture was then dehydrated under vacuum at 105℃ for 1 hour, followed by cooling to 70℃. Then, 20g of HDI trimer Desmodur N3390 (Covestro, NCO content 19.5wt%) and 0.15g of dibutyltin laurate (DBTL) were added. The mixture was heated to 85℃ and reacted for 4 hours. The reaction mixture was monitored by infrared spectroscopy at 2260-2280 cm⁻¹. -1 The reaction ends when the -NCO infrared absorption peak disappears, and the coupling agent is obtained by cooling.

[0043] The acrylic emulsion was cooled to 40°C, 2 parts by weight of coupling agent were added, and the pH of the emulsion system was adjusted to 8.0-8.5 with ammonia. The emulsion was then filtered to obtain a non-migratory soft porcelain emulsion.

[0044] Example 4

[0045] The acrylate emulsion has a raw material formulation that includes a pre-emulsion, a bottom liquid, and an initiator solution. The formulation and preparation method are the same as in Example 3.

[0046] The coupling agent was prepared by condensing fatty alcohol with ethylene oxide and emulsifier O-8 (seaweed, hydroxyl value 92.3 mg KOH / g) 34.2 g, which was then dehydrated under vacuum at 105 °C for 1 hour. The temperature was then lowered to 70 °C, and 20 g of IPDI trimer Desmodur Z4470 (Covestro, NCO content 11.8 wt%) and 0.12 g of dibutyltin laurate DBTL were added. The mixture was then heated to 85 °C and reacted for 4 hours. The reaction mixture was monitored by infrared spectroscopy at 2260-2280 cm⁻¹. -1 The reaction ends when the -NCO infrared absorption peak disappears, and the coupling agent is obtained by cooling.

[0047] The acrylic emulsion was cooled to 40°C, 3 parts by weight of coupling agent were added, and the pH of the emulsion system was adjusted to 8.0-8.5 with ammonia. The emulsion was then filtered to obtain a non-migratory soft porcelain emulsion.

[0048] Comparative Example 1 The anionic reactive emulsifier in the pre-emulsion was replaced with 1.5 parts by weight of sodium dodecylbenzenesulfonate, and the nonionic reactive emulsifier was replaced with 0.6 parts by weight of OP-10, with the rest being the same as in Example 1. The amount of coupling agent was 2 parts by weight.

[0049] Comparative Example 2 Based on Example 1, no coupling agent was added to the acrylate emulsion, and the rest was the same as in Example 1.

[0050] Comparative Example 3 Based on Example 1, trimethylolpropane trioleate was used instead of the coupling agent, with a dosage of 2 parts by weight, and the rest was the same as in Example 1.

[0051] Comparative Example 4 In Example 1, 2.5 parts by weight of octadecyl polyoxyethylene ether methacrylate were added to the pre-emulsion of component A, while no coupling agent was added to the acrylate emulsion, and the rest was the same as in Example 1.

[0052] Test section Emulsion stability test: Samples were diluted and the average particle size D50 and Zeta potential of the emulsion samples were measured using a laser particle size analyzer and electrophoretic light scattering, respectively. Referring to the standard GB / T 20623-2006, the calcium ion stability (48 hours) and thermal stability (60℃×7 days) of the emulsion samples were tested respectively. Emulsion curing conditions: The wet film thickness was 50 μm, and the film was dried by baking at 120℃ for 10 min to obtain the paint film sample.

[0053] The water resistance of the emulsion samples after film formation was tested in accordance with the standard GB / T1733-1993. According to the standard GB / T 9265-2009, the alkali resistance of the emulsion samples after film formation was tested; Referencing the standard GB / T 1865-2009, the weather resistance of the emulsion samples after film formation was tested.

[0054] The test results are listed in Table 1.

[0055] Table 1

[0056] Analysis of the data in Table 1 shows that the average particle size of the emulsions for flexible ceramic tiles prepared in Examples 1-4 is 175-193 nm, which belongs to fine-particle-size emulsions. The corresponding Zeta potential ranges from -60 to -65 mV. The extremely high negative Zeta potential indicates that the latex particles have a strong negative charge on their surface, generating a strong electrostatic repulsion force, thus exhibiting better colloidal stability. The corresponding thermal stability and calcium ion stability are also very strong. This is because Examples 1-4 use phosphate ester reactive emulsifiers. Their phosphate groups can not only be linked to the polymer chains in the final product, but also generate a strong chelating effect with calcium ions, preventing calcium ions from being compressed in the stabilizing double layer around the latex particles, thereby improving calcium ion stability.

[0057] Meanwhile, the emulsions in Examples 1-4 exhibited excellent water resistance, alkali resistance, and weather resistance after film formation, indicating that the polymer chains have better hydrophobicity and structural integrity after film formation. By designing and synthesizing a star-shaped coupling agent, hydrophilic polyoxyethylene ether segments exist in its side arms, while hydrophobic saturated hydrocarbon segments exist in the center and at the ends of the side arms. The hydrophilic polyoxyethylene ether segments can form hydrogen bonds with polar groups such as -COOH and -OH in the latex particles of the emulsion, thereby improving hydrophobicity and structural integrity after film formation. The core hydrophobic hydrocarbon structure and the terminal hydrophobic side chains provide shielding against polar hydrophilic groups and benzene rings that easily absorb ultraviolet light, thus improving the water resistance, alkali resistance, and weather resistance after film formation.

[0058] Comparative Example 1 added a coupling agent but did not use a phosphate ester reactive emulsifier. The emulsion synthesized by combining the conventional anionic emulsifier SDS with the nonionic emulsifier OP-10 had insufficient electrostatic stability, with a zeta potential of only -48 mV. Moreover, SDS and OP-10 lack unsaturated double bonds that can participate in the polymerization reaction, making it difficult to directly integrate into the polymer chain, resulting in poor calcium ion stability and resistance to media.

[0059] Comparative Example 2 used a combination of phosphate ester reactive emulsifiers and nonionic reactive emulsifiers, but no coupling agent was used. Although the electrostatic stability was good, the water resistance was extremely poor, indicating that there were defects in its hydrophobicity and structural compactness. The polar groups -COOH and -OH were directly exposed, which easily absorbed water and swelled, resulting in defects such as whitening and blistering of the paint film.

[0060] Comparative Example 3 did not use a coupling agent, but added trimethylolpropane trioleate to the emulsion as a replacement. Because trimethylolpropane trioleate is slightly soluble in water, the overall stability of the emulsion was reduced. Under high-temperature storage conditions, trimethylolpropane trioleate was prone to precipitation to form floating oil. Trimethylolpropane trioleate only has ester bonds and lacks polyoxyethylene ether segments with better hydrophilicity. The sites for forming hydrogen bonds with polar groups such as -COOH and -OH are limited. Moreover, ester bonds are easily hydrolyzed in alkaline environments. After film formation, the water resistance, alkali resistance and weather resistance of the paint film did not meet the expected targets.

[0061] Comparative Example 4 did not use a coupling agent, but added octadecyl polyoxyethylene ether methacrylate as a polymerizable monomer to participate in the reaction. However, the mismatch between its polymerization activity and migration rate meant that the free radicals generated by the water-soluble initiator mainly existed in the aqueous phase during the polymerization reaction. Octadecyl polyoxyethylene ether methacrylate has a certain degree of water solubility and can initiate polymerization in the aqueous phase to form oligomeric free radicals. However, the extremely long hydrophobic chains can drive to the surface of the nearest monomer droplets or latex particles, resulting in localized overpolymerization on the surface and leading to gelation. This manifests as a significant increase in the average particle size of the overall emulsion. Although a phosphate ester reactive emulsifier was used, it did not play a corresponding role. At the same time, due to the instability of emulsion polymerization, gelation easily occurred, resulting in a wide particle size distribution in the emulsion. Consequently, the film structure was not dense after formation, and the water resistance, alkali resistance, and weather resistance of the film did not meet the expected targets.

[0062] Finally, it should be noted that the above-described embodiments are merely illustrative of several implementation methods of this application, intended to facilitate a detailed understanding of the technical solutions of this application, but should not be construed as limiting the scope of protection of the patent application. It should be pointed out that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Furthermore, it should be understood that after reading the above teachings of this application, those skilled in the art can make various alterations or modifications to this application, and the equivalent forms obtained also fall within the scope of protection of this application. It should also be understood that technical solutions obtained by those skilled in the art based on the technical solutions provided in this application through logical analysis, reasoning, or limited experimentation are all within the scope of protection of the appended claims. Therefore, the scope of protection of this patent application should be determined by the content of the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A non-migratory soft ceramic specialty emulsion characterized in that, The emulsion comprises: an acrylate emulsion and a coupling agent; wherein the raw materials of the acrylate emulsion comprise: polymerizable monomers, an anionic reactive emulsifier, a non-ionic reactive emulsifier, an initiator and deionized water; the polymerizable monomers comprise at least one unsaturated double bond that can participate in a free radical polymerization reaction, and the polymerizable monomers comprise hard monomers, soft monomers and functional monomers; the hard monomers are polymerizable monomers with a homopolymer glass transition temperature greater than 0℃; the soft monomers are polymerizable monomers with a homopolymer glass transition temperature less than or equal to 0℃; the functional monomers are selected from one or more combinations of carboxyl-containing functional monomers, hydroxyl-containing functional monomers, amide-containing functional monomers and epoxy-containing functional monomers; the anionic reactive emulsifier is selected from (meth) acrylic acid alkyl phosphate, wherein the phosphate group is connected to the end of the alkyl chain of the (meth) acrylate; the non-ionic reactive emulsifier is selected from allyl or methacryloyloxy mono-terminated polyoxyethylene ether emulsifiers; the initiator is selected from ammonium persulfate or potassium persulfate; the coupling agent comprises an isocyanate multimer core and linear side arms, the linear side arms comprise polyoxyethylene chain segments and saturated alkyl chain segments, and at least 3 linear side arms are sequentially connected to the isocyanate multimer core, wherein the polyoxyethylene chain segments are directly connected to the isocyanate multimer core.

2. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, the hard monomers are selected from one or more of styrene, vinyl acetate, methyl methacrylate, methyl acrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate and acrylonitrile; and / or, the soft monomers are selected from one or more of ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, isooctyl acrylate and lauryl acrylate.

3. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, the carboxyl-containing functional monomers are selected from one or more of acrylic acid, methacrylic acid and itaconic acid; and / or, the hydroxyl-containing functional monomers are selected from one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate and hydroxypropyl methacrylate; and / or, the amide-containing monomers are selected from one or more of acrylamide and methacrylamide; and / or, the epoxy-containing monomers are selected from one or more of glycidyl acrylate and glycidyl methacrylate.

4. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, the anionic reactive emulsifier is selected from 2-methyl-2-acrylic acid-2-(phosphonoxy)ethyl ester; and / or, the non-ionic reactive emulsifier is selected from methacryloyloxy mono-terminated polyoxyethylene ether emulsifiers; and / or, the isocyanate multimer is selected from aliphatic isocyanate multimers; and / or, the preparation method of the coupling agent comprises: reacting an isocyanate multimer with an alkyl alcohol polyoxyethylene ether to obtain; and / or, dibutyltin laurate is used as a catalyst to catalyze the reaction of the isocyanate multimer with the alkyl alcohol polyoxyethylene ether.

5. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, The raw materials of the acrylate emulsion further comprise a pH buffer selected from sodium bicarbonate; And / or, the raw materials of the acrylate emulsion further include a post-elimination initiator, which includes tert-butyl peroxide and vitamin C.

6. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, The raw materials of the non-migratory soft porcelain special emulsion include, by weight, 50-70 parts of deionized water, 1-3 parts of anionic reactive emulsifier, 0.1-1 part of non-ionic reactive emulsifier, 15-30 parts of hard monomer, 15-30 parts of soft monomer, 2-8 parts of functional monomer, 2-8 parts of initiator, and 1-5 parts of coupling agent.

7. The non-migratory soft ceramic dedicated emulsion according to claim 1, characterized by, The raw materials of the non-migratory soft porcelain special emulsion include, by weight, 0.1-0.5 parts of pH buffer; And / or, the raw materials of the non-migratory soft porcelain special emulsion include, by weight, 0.5-2 parts of post-elimination initiator.

8. A process for the preparation of a non-migrating soft ceramic specific emulsion as claimed in any one of claims 1 to 7, comprising: Pre-emulsification, seed polymerization, dropwise addition, incubation and curing, and post-elimination reaction; The pre-emulsification includes dispersing 30-40 parts of deionized water, a formula amount of anionic reactive emulsifier, non-ionic reactive emulsifier, and polymerizable monomer to form a pre-emulsion; The seed polymerization is to add 5-15 parts of deionized water and a formula amount of pH buffer to the bottom of the kettle, prepare an initiator solution using 5-15 parts of deionized water and a formula amount of initiator, warm the kettle bottom liquid to 75-85℃, add 1-10wt% of the pre-emulsion and 10-30wt% of the initiator solution dropwise, and control the temperature at 80-85℃ to obtain a seed emulsion; The dropwise addition is to add the remaining initiator solution and pre-emulsion to the seed emulsion dropwise, and control the temperature at 80-85℃; The incubation and curing is to control the temperature at 80-90℃ after dropwise addition; The post-elimination reaction is to cool to 60-75℃ after incubation and curing, prepare a solution of 5-15 parts of deionized water and a formula amount of post-elimination initiator, and add it to the acrylate emulsion to promote complete reaction of unreacted monomers and improve conversion rate.

9. A paint film obtained by baking and drying the non-migratory soft porcelain special emulsion of any one of claims 1-7 at 80-130℃.

10. Use of the paint film of claim 9 on building decoration materials.

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