Microemulsion of fluorin containing crylic acid of self-crosslink in normal temperature and its production method

Abstract

The invention discloses a normal temperature self-crosslinked fluoro-containing polyacrylic acid microemulsion and its preparing process, wherein the microemulsion comprises the constituents of (methyl) acrylic ester, alkenyl carboxylic acid, alkenyl linking agent, ethenyl aromatic compound, alkenyl fluoro-containing alkyl ester, other olefins unsaturated monomer, initiating agent, buffering agent, emulsifying agent, neutralization agent and water. The preparation process comprises making seed emulsion under oxidation and reduction initiation system, then employing semi-continuous polymerization process to prepare the fluoro-containing polyacrylic acid microemulsion with good polymerization stability, small particle size, low film coating surface tension, and strong adhesion.

Description

technical field [0001] The invention relates to the field of polymer materials, in particular to a normal-temperature self-crosslinking fluorine-containing acrylic microemulsion and a preparation method thereof. Background technique [0002] Solvent-based fluororesins can cause environmental pollution and endanger human health. With the enhancement of people's awareness of environmental protection and the promulgation of relevant laws and regulations, the application and development of solvent-based fluororesins have been limited to a certain extent. In recent years, the research on waterborne fluororesin has attracted much attention. Fluorocarbon resin emulsion is a new type of water-based fluororesin. Due to the introduction of carbon-fluorine bonds with large bond energy in the emulsion polymer chain segment, the durability, stain resistance, and chemical resistance of the emulsion are greatly improved. , has the characteristics of high performan...

AI Technical Summary

Problems solved by technology

U.S. Patents US3324069, US4383075, and US4557977 disclose a method of firstly liquefying ethylenic fluorine-containing monomers such as gaseous tetrafluoroethylene, chlorotrifluoroethylene, vinyl fluoride, and vinylidene fluoride under relatively high pressure, and then performing emulsion polymerization. method; however, first of all, these methods need to be polymerized under high pressure, and the reaction process is difficult to control; secondly, due to the presence of chlorine atoms in the polymer chain segment, the prepared fluorocarbon resin emulsion has poor performance in weather resistance, chemical resistance, etc. Again, because the C-F group is distributed on the polymer main chain, cause the production cost of this emulsion to be higher, take this emulsion as the coating film adhesion performance of paint base material

There is also a method to prepare fluorocarbon resin emulsion with fluoroalkyl ethyl ethers as raw materials. Since fluoroalkyl ethyl ethers are liquid at room temperature, the reaction is relatively simple and the process is easy to control; but also due to the C-F group The group is on the main chain of the polymer, resulting in higher production costs of the emulsion, and poor adhesion of the coating film using the emulsion as the coating base material

In addition, there is another method to use fluoroalkyl (meth)acrylates as raw materials to prepare fluorocarbon resin emulsions. Since fluoroalkyl (meth)acrylates are liquid at room temperature, the reaction is relatively simple and the process is easy to control. ; And the bond energy of the C-F bond is large and stable, and its perfluorinated side chain terminal (-(CF 2 )nCF 3 , n=2~11) extend to the air and occupy the interface between the polymer and the air. This structure of side chain ends covering the main chain forms a good "shielding protection" for the internal molecules of the polymer, greatly reducing the Surface energy protects the main chain of the polymer; however, the emulsion has the disadvantages of excessively large latex particle size, poor polymerization stability, and weak adhesion, and because the fluoroalkyl (meth)acrylate monomer is expensive, the product cost still high