Preparation method of high-solid-content low-viscosity acrylate emulsion for sealing gum

Abstract

The invention relates to a preparation method of a high-solid-content low-viscosity acrylate emulsion for sealing gum. The preparation method is characterized by comprising the following steps of: in the presence of nitrogen, adding acrylate, a reactive emulsifier monomer, a latex protective agent and water to a vessel in a certain proportion, and uniformly stirring at room temperature to obtain a mixture liquid; and carrying out vacuumization and nitrogen introduction on a reactor repeatedly for three times, heating to 70-90 DEG C, adding an initiator aqueous solution which accounts for 0.1-0.8wt% of the monomer, dropwise adding 40 percent of the mixture liquid to the reactor, reacting for 15-30 minutes, adding a certain mass of anionic and non-ionic emulsifiers to the rest 60 percent of the mixture liquid to prepare a pre-emulsion, simultaneously dropwise adding the pre-emulsion and the initiator aqueous solution to the reactor, and keeping the constant temperature for 50 minutes after dropwise adding to prepare the acrylate emulsion. The preparation method has the advantages that the emulsion is high in solid content (70-82 percent), low in viscosity (300-600 mpa.s) and good in stability. The preparation method is used for preparing the acrylate-series sealing gum which is high in drying speed and small in shrinkage rate by adding the emulsion to filling and pigment paste.

Description

technical field [0001] The invention relates to the field of adhesives of organic polymer materials, in particular to a method for preparing a high-solid content and low-viscosity acrylate emulsion for sealants. Background technique [0002] In recent years, as countries around the world pay more and more attention to environmental pollution, water-based polymer systems have become one of the important development directions. Among them, the acrylate water-based system is easy to synthesize and has excellent performance. It is a chemical product with high added value and high profit. It develops very rapidly and is widely used as sealants, coatings, adhesives, etc. The acrylate emulsion sealant has been widely valued because of its excellent aging resistance, no solvent pollution, low price, no pollution and discoloration, and can be constructed on wet bases. As the main resin of sealant, acrylate emulsion has the advantages of good weather resistance, high hardness, bright...

AI Technical Summary

Problems solved by technology

Some researchers in China have achieved the synthesis of high-solid-content acrylate emulsion through complex means such as extraction, but the process is very complicated, which is not conducive to the realization of large-scale industrial production. Some researchers have also prepared high-solid-content acrylic acid by changing emulsifiers or polymerization methods. However, the solid content of ester emulsions is still below 70%, and the viscosity and stability cannot meet the conditions of practical application. Therefore, the industrial production of high solid content acrylate emulsions (solid content > 70%) has not yet been realized in China.

There are also foreign patent reports (US6040380) that can synthesize acrylate emulsion with a solid content of more than 70%, but its viscosity is high. When the solid content is 72%, the viscosity reaches 4500 mpa.s at 1 rpm, and its synthesis is more complicated. , a suitable seed emulsion must be synthesized first, and the second high-solid content emulsion polymerization can be carried out on the basis of the seed emulsion. When used in sealants, due to the high viscosity, it is not conducive to the high-speed stirring and mixing of other components in the later stage, so it cannot be used. Because of the sealant, it has not really realized industrial production

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