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CN-122006620-A - Preparation method of coating emulsion based on front-end polymerization process

CN122006620ACN 122006620 ACN122006620 ACN 122006620ACN-122006620-A

Abstract

The invention relates to a preparation method of a coating emulsion based on a front-end polymerization process. According to the method, through multi-scale time sequence segmentation and thermodynamic mapping, temperature intervals and peak temperature parameters of each stage of polymerization reaction are extracted accurately, multi-class phase change material microcapsules matched with temperature thresholds are designed, and uniform dispersion and potential stability of the microcapsules are realized. In the reaction process, real-time data are acquired by using distributed temperature sensing, the system temperature is dynamically monitored through data analysis, and the selective heat absorption and release of each gradient microcapsule are controlled according to signals, so that the fine buffering and adjustment of the local microenvironment temperature are realized. And the self-adaptive optimization of polymerization process parameters is realized by carrying out feedback analysis on temperature fluctuation and particle size distribution. The invention can obviously improve the control precision of the polymerization reaction temperature and the consistency of the latex particle diameter, inhibit the temperature spike and improve the quality and the process stability of the emulsion product.

Inventors

  • ZHAN YAOCHENG
  • ZHAN SHENGLIN

Assignees

  • 广州富思德新材料科技有限公司

Dates

Publication Date
20260512
Application Date
20260326

Claims (10)

  1. 1. A preparation method of a coating emulsion based on a front-end polymerization process specifically comprises the following steps: s1, acquiring temperature intervals of a nucleation period, an increase period and a curing period of a target emulsion polymerization process, and generating a polymerization stage temperature threshold parameter; s2, configuring an organic phase change material with a corresponding phase change peak temperature based on the temperature threshold parameter of the polymerization reaction stage, and constructing a gradient phase change microcapsule group; S3, dispersing the gradient phase change microcapsule group in deionized water for potential stabilization treatment to generate microcapsule suspension; s4, adding the microcapsule suspension serving as a water phase component into a polymerization reactor, and establishing an endogenous thermal buffering reaction system; s5, collecting real-time temperature data in the reaction system in the operation process of the endogenous thermal buffering reaction system to generate a real-time polymerization temperature sequence; s6, matching and matching the real-time polymerization temperature sequence with the polymerization reaction stage temperature threshold parameter to generate a phase change trigger state signal; S7, controlling the gradient phase change microcapsule group to execute endothermic or exothermic phase change according to the phase change trigger state signal, and outputting a local microenvironment temperature fluctuation value; And S8, calculating the particle size distribution index of the latex particles based on the local micro-environment temperature fluctuation value, and updating the temperature threshold parameter of the polymerization reaction stage of the next batch.
  2. 2. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 1, wherein the step S1 specifically comprises obtaining real-time reaction kinetics curve data of a target emulsion polymerization process, and performing characteristic point identification processing on the real-time reaction kinetics curve data to extract a polymerization reaction stage boundary marking sequence comprising a nucleation start point, a growth turning point and a curing end point.
  3. 3. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 2, wherein the step S1 specifically further comprises performing interval mapping calculation on the polymerization stage boundary marker sequence based on the polymerization stage boundary marker sequence to generate an initial polymerization temperature interval set covering a nucleation stage temperature window, an growth stage temperature window and a curing stage temperature window.
  4. 4. The method for preparing the coating emulsion based on the front-end polymerization process according to claim 1, wherein the step S2 specifically comprises the steps of performing interval analysis processing on the temperature threshold parameter of the polymerization reaction stage to extract the target phase-change temperature value of the nucleation stage, the target phase-change temperature value of the growth stage and the target phase-change temperature value of the curing stage, thereby generating three groups of independent phase-change temperature control indexes.
  5. 5. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 4, wherein the step S2 specifically further comprises searching and matching organic phase-change core materials with corresponding melting enthalpy values based on the three groups of independent phase-change temperature control indexes respectively to determine the selection schemes of n-tetradecane composite core materials, n-octadecane composite core materials and pentaerythritol composite core materials, and generating a core material bill.
  6. 6. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 5, wherein the step S2 specifically further comprises selecting polymer shell precursors having compatibility and a glass transition temperature higher than a highest temperature in a curing period according to chemical characteristics of each core material in the core material bill of materials, respectively, so as to construct a coating system of a polyurea shell layer, a methacrylic acid copolymer shell layer and a polyurethane interpenetrating network shell layer, and generating a shell formula parameter set.
  7. 7. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 1, wherein the step S3 specifically comprises: obtaining a gradient phase-change microcapsule group constructed by the previous step and deionized water medium, and performing pre-dispersion treatment on the gradient phase-change microcapsule group to generate initial mixed slurry containing unstabilized microcapsule particles; Receiving the initial mixed slurry, and performing a high-energy shearing dispersion operation on the initial mixed slurry to break microcapsule agglomerates and generate a microcapsule crude dispersion having a preliminary spatial separation characteristic; collecting surface charge state data of the microcapsule crude dispersion liquid, and calculating the current Zeta potential value of the microcapsule crude dispersion liquid based on an electric double layer theory to generate potential feedback parameters representing colloid stability; according to the potential feedback parameter and a preset negative potential threshold interval, adopting a pH regulator dripping strategy to perform surface functional group ionization degree regulation and control treatment on the microcapsule crude dispersion liquid so as to generate potential optimization dispersion liquid with high electrostatic repulsive force; And monitoring the rheological property and the potential stability index of the potential optimization dispersion liquid, and executing final homogenization packaging treatment on the potential optimization dispersion liquid to output microcapsule suspension liquid meeting the polymerization feeding requirement.
  8. 8. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 1, wherein the step S4 specifically comprises: detecting rheological property and solid content parameters of microcapsule suspension in real time, calculating an optimal feeding rate curve based on rheological property data and the solid content parameters, and generating a dynamic feeding control instruction adapting to the stirring power of a polymerization reactor; driving a metering pump to quantitatively convey microcapsule suspension according to a dynamic feeding control instruction, and introducing the microcapsule suspension into a premixing chamber of a polymerization reactor to generate microcapsule-water phase premixing fluid with a preliminary dispersion state; performing high-shear emulsification on microcapsule-water phase premix fluid, and adjusting the intensity distribution of a shear field to enable the microcapsules to reach a micron-sized uniform dispersion state in a continuous water phase so as to generate microcapsule dispersion emulsion with uniform spatial distribution; Multiphase mixing the microcapsule dispersion emulsion, a monomer oil phase and an initiator solution in a polymerization reactor to promote macro homogenization of each phase and generate a complete polymerization reaction precursor mixture containing gradient phase change microcapsules; And starting an endogenous thermal buffering mechanism verification program based on the initial distribution characteristics of a temperature field of the complete polymerization reaction precursor mixture, confirming the space co-location state of the gradient phase-change microcapsule in a reaction medium, and establishing an endogenous thermal buffering reaction system with self-adaptive thermal regulation.
  9. 9. The method of claim 8, wherein the rotor linear velocity of the high shear emulsification process is 8-12 m/s, and the stator pore diameter is 0.5-1.0 mm.
  10. 10. The method for preparing a coating emulsion based on a front-end polymerization process according to claim 1, wherein the step S5 specifically comprises: Acquiring original optical signal data of a distributed optical fiber temperature sensor array deployed at different radial and axial positions in a polymerization reactor, extracting spectral features from the original optical signal data, and separating an initial temperature measurement value set corresponding to each space coordinate point; Receiving an initial temperature measurement value set, performing dynamic noise suppression and time sequence prediction correction on the initial temperature measurement value set, eliminating instantaneous thermal disturbance noise caused by stirring turbulence and outputting a smoothed standard temperature sampling point sequence; performing time stamp alignment processing on the standard temperature sampling point sequence, eliminating acquisition time delay differences among different sensor nodes, and generating a synchronized temperature space-time matrix with a unified time reference; based on the synchronous temperature space-time matrix, extremum screening and mean value fusion operation are carried out on the temperature field distribution characteristics at each moment in the matrix, and key temperature characteristic scalar representing the overall thermal state of the reaction system is extracted; And carrying out structured packaging treatment on the key temperature feature scalar according to a preset time sequence format, and generating a real-time aggregation temperature sequence comprising continuous time dimension and accurate temperature values by utilizing an industrial real-time database protocol, wherein the real-time aggregation temperature sequence is used as a direct data source for generating a phase change trigger state signal.

Description

Preparation method of coating emulsion based on front-end polymerization process Technical Field The invention relates to the technical field of thermal management and particle size regulation of emulsion polymerization processes, in particular to a preparation method of a coating emulsion based on a front-end polymerization process. Background The preparation process of the current coating emulsion is widely applied to the production fields of special paper, adhesives, coatings and related high polymer materials, and the precise control of emulsion polymerization temperature has a direct decisive effect on the nucleation process, particle size distribution, particle morphology and downstream film forming performance of emulsion particles. The existing emulsion polymerization system generally adopts a jacket heating/cooling, immersed heat exchanger or continuous external circulation heat exchange structure, adjusts the overall temperature of the reactor through external heat source or cold source input, and is assisted with a traditional PID temperature controller to realize temperature setting and maintenance of each stage of the polymerization process. Strategies such as temperature multi-stage program temperature control, thermostatic plate partition control, dynamic heat flow feedback and the like are also explored in part of literature and existing patents to enhance the uniformity of latex particle size and film forming performance. However, such temperature management methods are still generally biased towards steady-state maintenance of the macroscopic overall thermal field, lacking precise means of regulation of the "highly coupled relationship of partial discharge/endothermic transients and particle size evolution" in the reactive microenvironment. From the aspect of industry demand, the existing temperature control scheme based on external thermal field control has the main defects that firstly, the heat exchange reaction rate of an external jacket or a circulating fluid is limited by the heat conductivity coefficient and the fluid mixing uniformity, the rapid heat release in a short time is difficult to absorb in time, local agglomeration or nucleation 'trampling event' is easy to cause, secondly, the integral temperature control response speed of PID is limited, micro-area fine decoupling of a nucleation area, a growth area, a curing area and other reaction stages cannot be realized, only zone temperature setting can be provided, and dynamic matching of actual heat flow change is difficult to realize, thirdly, the problems of high solid content, high-speed excitation, large-scale parallelization, temperature field disturbance and uneven particle size are more prominent along with the process trend, and the promotion of emulsion product performance and the expansion of industrialized application range are restricted. Disclosure of Invention The application provides a preparation method of coating emulsion based on a front-end polymerization process, which aims to solve one of the problems or one of the problems of the prior art mentioned in the background art. The application provides a preparation method of a coating emulsion based on a front-end polymerization process, which specifically comprises the following steps: S1, obtaining temperature ranges of a nucleation period, an increase period and a curing period of a target emulsion polymerization process, and generating a polymerization stage temperature threshold parameter. And S2, configuring an organic phase change material with a corresponding phase change peak temperature based on the temperature threshold parameter of the polymerization reaction stage, and constructing a gradient phase change microcapsule group. And S3, dispersing the gradient phase change microcapsule group in deionized water for potential stabilization treatment to generate microcapsule suspension. And S4, adding the microcapsule suspension serving as an aqueous phase component into a polymerization reactor, and establishing an endogenous thermal buffering reaction system. S5, collecting real-time temperature data in the reaction system in the operation process of the endogenous thermal buffering reaction system to generate a real-time polymerization temperature sequence. And S6, matching and matching the real-time polymerization temperature sequence with the polymerization reaction stage temperature threshold parameter to generate a phase change trigger state signal. And S7, controlling the gradient phase-change microcapsule group to execute endothermic or exothermic phase change according to the phase-change trigger state signal, and outputting a local microenvironment temperature fluctuation value. And S8, calculating the particle size distribution index of the latex particles based on the local micro-environment temperature fluctuation value, and updating the temperature threshold parameter of the polymerization reaction stage of the next batch. The preparation me