Water-based polyacrylic resin self-foaming emulsion as well as preparation method and application thereof

Abstract

The invention discloses a water-based polyacrylic resin self-foaming emulsion as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The water-based acrylic acid emulsion is prepared from the following components in percentage by mass: 0.61 percent to 0.64 percent of acrylic acid, 2.4 percent to 2.5 percent of hydroxyethyl acrylate, 12.2 percent to 12.5 percent of methyl methacrylate, 15.3 percent to 15.7 percent of butyl acrylate, 2.6 percent to 7.8 percent of methacrylic acid long-chain alkyl ester, 1.4 percent to 2.0 percent of N-hydroxymethyl acrylamide, 0.3 percent to 0.4 percent of an initiator and 1.4 percent to 1.6 percent of a compound emulsifier, 0.4%-0.5% of a pH regulator and the balance of deionized water; wherein the acrylic acid, the hydroxyethyl acrylate, the methyl methacrylate, the butyl acrylate, the methacrylic acid long-chain alkyl ester and the N-hydroxymethyl acrylamide form a mixed monomer; the compound emulsifier is an emulsifier formed by compounding sodium dodecyl sulfate and OP-10. The material can spontaneously form a uniform and fine foam structure in the coating process, and the foaming process can be completed only by simple stirring without additionally adding a foaming agent, so that the production process is simplified, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to an aqueous polyacrylic acid resin self-foaming emulsion, its preparation method, and its application. Background Technology

[0002] Foam coating is a type of fabric coating technology, belonging to direct coating. This process involves adding a certain proportion of foaming agents and other additives to a coating material, using foaming equipment to create foam of a specific mass. After a series of drying processes, a microporous coating structure is finally applied to the material surface. Compared to direct coating, the introduction of air increases the volume of the coating, thus reducing the amount of coating used by 70%-90% when coating the same size fabric. Furthermore, incorporating a large amount of air into the coating reduces the moisture content of the same volume of coating, increasing the drying speed, reducing the energy required for drying, saving costs, and shortening the work cycle.

[0003] However, traditional foam coating technology typically relies on external foaming agents or complex foaming equipment to achieve cell formation, which not only increases production costs but may also have a certain impact on the environment. In addition, traditional foam coatings face challenges in terms of cell uniformity and density control, affecting the performance and application range of the coating material.

[0004] Therefore, developing a self-foaming coating material that can spontaneously form pores during the coating process has significant practical application value. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide an aqueous polyacrylic acid resin self-foaming emulsion, its preparation method and application. This material can spontaneously form a uniform and delicate cell structure during the coating process. No additional foaming agent is required; the foaming process can be completed simply by stirring, thereby simplifying the production process and improving production efficiency.

[0006] To achieve the above objectives, the present invention employs the following technical solution: This invention provides an aqueous self-foaming polyacrylic acid resin emulsion, comprising, by weight percentage: 0.61%-0.64% acrylic acid, 2.4%-2.5% hydroxyethyl acrylate, 12.2%-12.5% ​​methyl methacrylate, 15.3%-15.7% butyl acrylate, 2.6%-7.8% long-chain alkyl methacrylate, 1.4%-2.0% N-hydroxymethylacrylamide, 0.3%-0.4% initiator, 1.4%-1.6% composite emulsifier; 0.4%-0.5% pH adjuster, with the remainder being deionized water; The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10.

[0007] In one embodiment, the initiator is ammonium persulfate; the pH adjuster is sodium bicarbonate.

[0008] In one embodiment, the mass ratio of sodium dodecyl sulfonate to OP-10 is 1:1 to 1:3.

[0009] In one embodiment, the long-chain alkyl methacrylate is any one of isooctyl methacrylate, lauryl methacrylate, and hard methacrylate.

[0010] This invention also provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: A mixed monomer was prepared by combining acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide; a composite emulsifier was prepared by compounding sodium dodecyl sulfonate and OP-10. Add 1 / 5 of the mass of deionized water to the initiator and stir to obtain a clear initiator solution; Add the remaining 4 / 5 of the mass of deionized water to the composite emulsifier, stir until the composite emulsifier dissolves, then add 1 / 4 of the mass of the mixed monomers, stir to perform monomer pre-emulsification, and obtain a pre-emulsion. Add 1 / 5 of the mass of the initiator solution to the pre-emulsion and stir until the reaction solution turns into a light blue solution; then add the remaining mixed monomers and initiator solution dropwise within a set time and keep the reaction at a constant temperature to obtain an aqueous polyacrylic acid resin self-foaming emulsion.

[0011] In one embodiment, the temperature at which the composite emulsifier is stirred until it dissolves is 80°C-85°C.

[0012] In one embodiment, the stirring speed during monomer pre-emulsification is 600-700 r / min; the monomer pre-emulsification time is 20-30 min.

[0013] In one embodiment, the stirring speed during the reaction is 250-350 r / min; the reaction time is 20-30 min.

[0014] In one embodiment, the set time is 2 hours; the heat preservation reaction time is 2 hours.

[0015] The present invention also provides an application of the above-described waterborne polyacrylic acid resin self-foaming emulsion in fabric coating, the specific application process of which is as follows: A self-foaming emulsion of waterborne polyacrylic resin is mechanically stirred and foamed to obtain a foaming slurry. The foaming slurry is then coated onto a substrate and dried to obtain a self-foaming coating of waterborne polyacrylic resin.

[0016] In one embodiment, the mechanical stirring and foaming speed is 1000 r / min, the mechanical stirring and foaming time is 10 min, the drying time is 1 h, and the drying temperature is 100°C.

[0017] Furthermore, a waterborne polyacrylic resin self-foaming coating, as described above, can be applied to polymer chemical coatings.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a water-based self-foaming polyacrylic acid resin emulsion, whose main raw materials are acrylic acid monomers (acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, N-hydroxymethylacrylamide), ammonium persulfate initiator, composite emulsifier OP-10 and sodium dodecyl sulfonate, and a certain amount of water. The specially formulated OP-10 and sodium dodecyl sulfonate act as composite emulsifiers, functioning as surfactants to reduce the surface tension between liquid and gas, thus promoting bubble formation. The polyacrylic acid resin, polymerized from acrylic acid monomers, is a high-molecular-weight material that increases the viscosity of the liquid, delaying liquid film drainage and thus ensuring more stable foam formation. The presence of the polyacrylic acid resin polymer enhances the strength of the liquid film, improving its elasticity and toughness, further contributing to the stability of the foam. The water-based polyacrylic acid emulsion synthesized by this invention has a self-foaming function, requiring no additional foaming agent during use; stable foam can be produced simply through mechanical stirring, saving raw materials when used on fabric surfaces. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the preparation process of a waterborne polyacrylic acid resin self-foaming emulsion according to the present invention. Figure 2 This is a diagram illustrating the bubble formation mechanism of a waterborne polyacrylic acid resin self-foaming emulsion according to the present invention. Figure 3 Infrared spectral images of the samples prepared in Examples 1, 2, and 3 of this invention; Figure 4 The graph shows the foam half-life test results of the sample in the embodiment of the present invention; Figure 5 The image shows the coating pore size test results of the sample in the embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] 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. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] This invention discloses an aqueous polyacrylic acid resin self-foaming emulsion, its preparation method, and its application.

[0027] This invention provides an aqueous self-foaming polyacrylic acid resin emulsion, comprising, by weight percentage: 0.61%-0.64% acrylic acid, 2.4%-2.5% hydroxyethyl acrylate, 12.2%-12.5% ​​methyl methacrylate, 15.3%-15.7% butyl acrylate, 2.6%-7.8% long-chain alkyl methacrylate, 1.4%-2.0% N-hydroxymethylacrylamide, 0.3%-0.4% initiator, 1.4%-1.6% composite emulsifier; 0.4%-0.5% pH adjuster, with the remainder being deionized water. The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10.

[0028] The initiator is preferably ammonium persulfate, the pH adjuster is preferably sodium bicarbonate, and the mass ratio of sodium dodecyl sulfonate and OP-10 is 1:1 to 1:3. The long-chain alkyl methacrylate is any one of isooctyl methacrylate, lauryl methacrylate, and hard methacrylate.

[0029] The acrylic monomers used are inexpensive and widely available. OP-10 and sodium dodecyl sulfonate are composite emulsifiers, acting as surfactants to effectively reduce the surface tension between liquid and gas, providing a favorable environment for foam formation. The polymerized polyacrylic acid resin is a high-molecular-weight polymer that increases the viscosity of the liquid, thereby delaying the drainage of the liquid film and allowing the foam to persist for a longer period. The high-molecular-weight polymer generated in this invention enhances the toughness and elasticity of the film, thus enabling the foam to exist stably.

[0030] In another aspect, the present invention provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide were used to form a mixed monomer; the mixed monomer was weighed in beaker A according to the proportions of the formula; sodium dodecyl sulfonate and OP-10 were compounded to prepare a composite emulsifier; Weigh out the initiator ammonium persulfate in beaker B, add 1 / 5 of the mass of deionized water to the initiator, and stir to obtain a clear initiator solution; Add the remaining 4 / 5 of the mass of deionized water to the three-necked flask, add the composite emulsifier according to the formula ratio, and stir at 80℃-85℃ until the composite emulsifier is dissolved. Then, take 1 / 4 of the mass of the mixed monomer in beaker A and add it to the three-necked flask. Stir the monomer at 600-700 r / min for 20-30 min to pre-emulsify it and obtain the pre-emulsion. Add 1 / 5 of the initiator solution from beaker B to the pre-emulsion and continue stirring at 250-350 r / min for 20-30 min until the reaction solution turns into a light blue solution; then add the remaining mixed monomers and initiator solution dropwise over 2 h and keep the reaction at the temperature for 2 h to obtain an aqueous polyacrylic acid resin self-foaming emulsion.

[0031] The preparation principle is as follows: acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacryloyl monomer are first pre-emulsified, then a portion of the initiator is added for seed polymerization, and then the remaining monomer and initiator are added. Since the hydrophilic and hydrophobic groups in the monomer reach a certain ratio, a self-foaming surfactant is formed.

[0032] Among them, the preparation process of waterborne polyacrylic acid resin includes a typical reaction process as follows: Figure 1 As shown in the figure. In the figure, a is the degree of polymerization of N-hydroxymethylacrylamide, b is the degree of polymerization of methyl methacrylate, c is the degree of polymerization of acrylic acid, d is the degree of polymerization of hydroxyethyl acrylate, e is the degree of polymerization of butyl acrylate, and m is the degree of polymerization of long-chain alkyl methacrylate.

[0033] In another aspect, this invention provides the application of the above-mentioned waterborne polyacrylic acid resin self-foaming emulsion in fabric coating, and the specific application process is as follows: A self-foaming emulsion of waterborne polyacrylic resin was mechanically stirred and foamed at 1000 r / min for 10 min to obtain a foaming slurry. The foaming slurry was then coated onto a substrate and dried at 100℃ for 1 h to obtain a self-foaming coating of waterborne polyacrylic resin.

[0034] like Figure 2 As shown, the formation of bubbles in this waterborne polyacrylic acid resin self-foaming emulsion is achieved through the following process: Under stirring, air enters the emulsion and acts as the gas nuclei for foaming; the synthesized polyacrylate polymer chain contains hydrophilic hydroxyl and carboxyl groups, as well as hydrophobic long chains, so a portion of the polyacrylate can form a surface tension-reducing film, further promoting foam formation. Finally, under the combined action of the emulsifier sodium dodecyl sulfonate and OP-10, and the synthesized polymer, a transition layer is formed. Because the synthesized polymer has a certain degree of toughness, it can prolong the foam's existence time and enhance its stability.

[0035] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0036] Example 1 This embodiment provides an aqueous polyacrylic acid resin self-foaming emulsion, which, by mass percentage, comprises 0.61% acrylic acid, 2.4% hydroxyethyl acrylate, 12.2% methyl methacrylate, 15.3% butyl acrylate, 2.6% long-chain alkyl methacrylate, 1.4% N-hydroxymethylacrylamide, 0.3% initiator, 1.4% composite emulsifier, 0.4% pH adjuster, and 63.39% water.

[0037] The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10 in a 1:1 mass ratio; the long-chain alkyl methacrylate is isooctyl methacrylate; the initiator is ammonium persulfate; and the pH adjuster is sodium bicarbonate.

[0038] Another aspect of this embodiment provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Weigh the mixed monomers into beaker A according to the mass percentage in the formula; weigh the initiator ammonium persulfate into beaker B, then add 1 / 5 of the mass of water and stir until dissolved to obtain a clear initiator solution; add the remaining water and composite emulsifier into a three-necked flask, heat and stir at 80°C until the composite emulsifier is completely dissolved, then add 1 / 4 of the mass of the mixed monomers, and perform monomer pre-emulsification stirring at 600 r / min for 20 min to obtain a pre-emulsion; then add 1 / 5 of the mass of the initiator solution from beaker B to the pre-emulsion, adjust the stirring speed to 250 r / min, and continue the reaction for 20 min. Observe that the emulsion turns blue. Add the remaining monomer initiator solution dropwise into the three-necked flask over two hours. After the addition is complete, keep the reaction at the temperature for two hours to obtain the emulsion.

[0039] Example 2 This embodiment provides an aqueous polyacrylic acid resin self-foaming emulsion, which, by mass percentage, comprises 0.64% acrylic acid, 2.5% hydroxyethyl acrylate, 12.5% ​​methyl methacrylate, 15.7% butyl acrylate, 7.8% long-chain alkyl methacrylate, 2.0% N-hydroxymethylacrylamide, 0.4% initiator, 1.6% composite emulsifier, 0.5% pH adjuster, and 56.36% water.

[0040] The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10 in a mass ratio of 1:3; the long-chain alkyl methacrylate is lauryl methacrylate; the initiator is ammonium persulfate; and the pH adjuster is sodium bicarbonate.

[0041] Another aspect of this embodiment provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Weigh the mixed monomers into beaker A according to the mass percentage in the formula; weigh the initiator ammonium persulfate into beaker B, then add 1 / 5 of the mass of water and stir until dissolved to obtain a clear initiator solution; add the remaining water and composite emulsifier into a three-necked flask, heat and stir at 85°C until the composite emulsifier is completely dissolved, then add 1 / 4 of the mass of the mixed monomers, and stir the monomers at 700 r / min for 30 min to obtain a pre-emulsion; then add 1 / 5 of the mass of the initiator solution from beaker B to the pre-emulsion, adjust the stirring speed to 350 r / min, and continue the reaction for 30 min. Observe that the emulsion turns blue. Add the remaining monomer initiator solution dropwise into the three-necked flask over two hours. After the addition is complete, keep the reaction at the temperature for two hours to obtain the emulsion.

[0042] Example 3 This embodiment provides an aqueous polyacrylic acid resin self-foaming emulsion, which, by mass percentage, comprises 0.64% acrylic acid, 2.5% hydroxyethyl acrylate, 12.5% ​​methyl methacrylate, 15.7% butyl acrylate, 7.8% long-chain alkyl methacrylate, 2.0% N-hydroxymethylacrylamide, 0.4% initiator, 1.6% composite emulsifier, 0.5% pH adjuster, and 56.36% water.

[0043] The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10 in a mass ratio of 1:3; the long-chain alkyl methacrylate is hard methacrylate; the initiator is ammonium persulfate; and the pH adjuster is sodium bicarbonate.

[0044] Another aspect of this embodiment provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Weigh the mixed monomers into beaker A according to the mass percentage in the formula; weigh the initiator ammonium persulfate into beaker B, then add 1 / 5 of the mass of water and stir until dissolved to obtain a clear initiator solution; add the remaining water and composite emulsifier into a three-necked flask, heat and stir at 85°C until the composite emulsifier is completely dissolved, then add 1 / 4 of the mass of the mixed monomers, and stir the monomers at 700 r / min for 30 min to obtain a pre-emulsion; then add 1 / 5 of the mass of the initiator solution from beaker B to the pre-emulsion, adjust the stirring speed to 350 r / min, and continue the reaction for 30 min. Observe that the emulsion turns blue. Add the remaining monomer initiator solution dropwise into the three-necked flask over two hours. After the addition is complete, keep the reaction at the temperature for two hours to obtain the emulsion.

[0045] Example 4 This embodiment provides an aqueous polyacrylic acid resin self-foaming emulsion, which, by mass percentage, comprises 0.64% acrylic acid, 2.5% hydroxyethyl acrylate, 12.5% ​​methyl methacrylate, 15.7% butyl acrylate, 7.8% long-chain alkyl methacrylate, 2.0% N-hydroxymethylacrylamide, 0.4% initiator, 1.6% composite emulsifier, 0.5% pH adjuster, and 56.36% water.

[0046] The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10 in a mass ratio of 1:2; the long-chain alkyl methacrylate is lauryl methacrylate; the initiator is ammonium persulfate; and the pH adjuster is sodium bicarbonate.

[0047] Another aspect of this embodiment provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Weigh the mixed monomers into beaker A according to the mass percentage in the formula; weigh the initiator ammonium persulfate into beaker B, then add 1 / 5 of the mass of water and stir until dissolved to obtain a clear initiator solution; add the remaining water and composite emulsifier into a three-necked flask, heat and stir at 80°C until the composite emulsifier is completely dissolved, then add 1 / 4 of the mass of the mixed monomers, and stir the monomers at 700 r / min for 30 min to obtain a pre-emulsion; then add 1 / 5 of the mass of the initiator solution from beaker B to the pre-emulsion, adjust the stirring speed to 300 r / min, and continue the reaction for 30 min. Observe that the emulsion turns blue. Add the remaining monomer initiator solution dropwise into the three-necked flask over two hours. After the addition is complete, keep the reaction at the temperature for two hours to obtain the emulsion.

[0048] Example 5 This embodiment provides an aqueous polyacrylic acid resin self-foaming emulsion, which, by mass percentage, comprises 0.64% acrylic acid, 2.5% hydroxyethyl acrylate, 12.5% ​​methyl methacrylate, 15.7% butyl acrylate, 7.8% long-chain alkyl methacrylate, 2.0% N-hydroxymethylacrylamide, 0.4% initiator, 1.6% composite emulsifier, 0.5% pH adjuster, and 56.36% water.

[0049] The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10 in a mass ratio of 1:3; the long-chain alkyl methacrylate is lauryl methacrylate; the initiator is ammonium persulfate; and the pH adjuster is sodium bicarbonate.

[0050] Another aspect of this embodiment provides a method for preparing an aqueous polyacrylic acid resin self-foaming emulsion, comprising the following steps: Weigh the mixed monomers into beaker A according to the mass percentage in the formula; weigh the initiator ammonium persulfate into beaker B, then add 1 / 5 of the mass of water and stir until dissolved to obtain a clear initiator solution; add the remaining water and composite emulsifier into a three-necked flask, heat and stir at 85°C until the composite emulsifier is completely dissolved, then add 1 / 4 of the mass of the mixed monomers, and perform monomer pre-emulsification stirring at 600 r / min for 30 min to obtain a pre-emulsion; then add 1 / 5 of the mass of the initiator solution from beaker B to the pre-emulsion, adjust the stirring speed to 350 r / min, and continue the reaction for 20 min. Observe that the emulsion turns blue. Add the remaining monomer initiator solution dropwise into the three-necked flask over two hours. After the addition is complete, keep the reaction at the temperature for two hours to obtain the emulsion.

[0051] Characterization and testing: To characterize the application performance of this waterborne polyacrylic acid resin self-foaming emulsion, the product prepared in the examples was used as a sample and the following tests were performed: 1. Infrared testing Using Examples 1, 2, and 3 as samples, the infrared spectra of the samples were measured using a Fourier transform infrared spectrometer, as shown below. Figure 3 As shown, at 3500 cm -1 The peak at 2900 cm⁻¹ represents the stretching vibration of OH; however, due to the low content of hydroxyl groups, the peak is not obvious. -1 The peak is the stretching vibration peak of -COOH; at 1731 cm⁻¹. -1 A set of strong absorption peaks appeared, which are C=O absorption peaks, originating from various monomers. Infrared testing showed that the product had been successfully prepared.

[0052] 2. Foam half-life test 10g of the emulsion in this example was weighed into a beaker and prepared into a foaming slurry using mechanical foaming. The prepared foaming slurry was poured into a stoppered graduated cylinder, and the height of the foam layer was recorded every 30 minutes to obtain the foam half-life. Experimental conditions: foaming speed 1000 r / min, foaming time 10 min, foaming ratio 2.

[0053] Depend on Figure 4 The half-life test results of the sample foam in the example shown indicate that the half-life of the sample foam prepared in the example is between 100 min and 130 min, which shows good foam stabilization effect.

[0054] 3. Preparation of foamed coating Weigh 10g of emulsion into a beaker and use a scraper to evenly coat the foaming slurry onto the release paper, with a coating thickness of approximately 2mm. After coating, place the foamed coating in a forced-air drying oven to dry at 100℃ for 1 hour. Experimental conditions: foaming speed 1000r / min, foaming time 10min, foaming ratio 2.

[0055] like Figure 5 As shown in the coating pore size test results, the pore size of the prepared foamed coating is between 130μm and 150μm. The pore size of the coating is uniform, and it can adhere evenly to the substrate surface during use.

[0056] Table 1 Emulsion Properties

[0057] As shown in Table 1, the prepared emulsion has a solid content of 30%, a viscosity of about 43 MPa·s, a uniform milky white appearance, and a centrifugal stability of >60 days, which meets the requirements of the coating application standards.

[0058] In summary, the waterborne polyacrylic acid resin foaming emulsion prepared by this invention has excellent foaming ability and can exist stably. The coating formed during use also has a relatively stable pore size, which simplifies the use process, can save costs, and meets environmental protection requirements.

[0059] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A water-based self-foaming polyacrylic acid resin emulsion, characterized in that, By weight percentage, it includes 0.61%-0.64% acrylic acid, 2.4%-2.5% hydroxyethyl acrylate, 12.2%-12.5% ​​methyl methacrylate, 15.3%-15.7% butyl acrylate, 2.6%-7.8% long-chain alkyl methacrylate, 1.4%-2.0% N-hydroxymethylacrylamide, 0.3%-0.4% initiator, 1.4%-1.6% compound emulsifier, 0.4%-0.5% pH adjuster, and the remainder is deionized water. The mixture consists of acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide as monomers; the composite emulsifier is an emulsifier composed of sodium dodecyl sulfonate and OP-10.

2. The waterborne polyacrylic acid resin self-foaming emulsion according to claim 1, characterized in that, The initiator is ammonium persulfate.

3. The waterborne polyacrylic acid resin self-foaming emulsion according to claim 1, characterized in that, The pH adjuster is sodium bicarbonate.

4. The waterborne polyacrylic acid resin self-foaming emulsion according to claim 1, characterized in that, The mass ratio of sodium dodecyl sulfonate to OP-10 is 1:1 to 1:

3.

5. The waterborne polyacrylic acid resin self-foaming emulsion according to claim 1, characterized in that, The long-chain alkyl methacrylate is any one of isooctyl methacrylate, lauryl methacrylate, and hard methacrylate.

6. A method for preparing the waterborne polyacrylic acid resin self-foaming emulsion according to any one of claims 1 to 5, characterized in that, The following steps are involved: A mixed monomer was prepared by combining acrylic acid, hydroxyethyl acrylate, methyl methacrylate, butyl acrylate, long-chain alkyl methacrylate, and N-hydroxymethylacrylamide; a composite emulsifier was prepared by compounding sodium dodecyl sulfonate and OP-10. Add 1 / 5 of the mass of deionized water to the initiator and stir to obtain a clear initiator solution; Add the remaining 4 / 5 of the mass of deionized water to the composite emulsifier, stir until the composite emulsifier dissolves, then add 1 / 4 of the mass of the mixed monomers, stir to perform monomer pre-emulsification, and obtain a pre-emulsion. Add 1 / 5 of the mass of the initiator solution to the pre-emulsion and stir until the reaction solution turns into a light blue solution; then add the remaining mixed monomers and initiator solution dropwise within a set time and keep the reaction at a constant temperature to obtain an aqueous polyacrylic acid resin self-foaming emulsion.

7. The method for preparing the waterborne polyacrylic acid resin self-foaming emulsion according to claim 6, characterized in that, The temperature at which the composite emulsifier is dissolved during stirring is 80℃-85℃.

8. The method for preparing the waterborne polyacrylic acid resin self-foaming emulsion according to claim 6, characterized in that, The stirring speed for monomer pre-emulsification is 600-700 r / min; the monomer pre-emulsification time is 20-30 min.

9. The method for preparing the waterborne polyacrylic acid resin self-foaming emulsion according to claim 6, characterized in that, The stirring speed during the reaction is 250-350 r / min; the reaction time is 20-30 min; the set time is 2 h; and the heat preservation reaction time is 2 h.

10. An application of the waterborne polyacrylic acid resin self-foaming emulsion as described in any one of claims 1 to 5 in fabric coating, characterized in that, The application process is as follows: A self-foaming emulsion of waterborne polyacrylic resin is mechanically stirred and foamed to obtain a foaming slurry. The foaming slurry is then coated onto a substrate and dried to obtain a self-foaming coating of waterborne polyacrylic resin.

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