Composite ball containing self-assembly microcapsule and preparation method thereof

Abstract

The invention provides an in-situ preparation method for capsules with amino resin as wall forming monomer. The method comprises the following steps that firstly, the alkanol etherified amino resin with different carbon chain lengths and an oil soluble substance are mixed and stirred fully to be dissolved, and a uniform oil phase is obtained; secondly, the prepared uniform oil phase is added into a water solution containing an emulsifier, the mixture is stirred fully, sheared and emulsified, and emulsion droplets with the particle size ranging from 1 micron to 100 microns are obtained; thirdly, a water-soluble polymer solution and the emulsion are mixed and jetted, and a composite ball containing uniform dispersion emulsion is prepared; fourthly, the mixed solution of the composite ball and a salt solution is slowly heated, the pH value is adjusted, the emulsion droplets of the etherified amino resin inside the composite ball are subjected to a polymerization curing reaction, and a capsule wall of a microcapsule for wrapping the oil phase is formed; fifthly, after filtering and washing, the composite ball containing the self-assembly microcapsule is obtained, and the particle size of composite balls is uniform. The synthetic process is simple, energy consumption is low, the requirements for equipment is low, reaction conditions and the particle size are easy to control, and the method has a prospect of mass production. The simple encapsulation method has very wide application prospects in the fields of pesticide, cosmetics and intelligent heat accumulation thermoregulation products.

Description

technical field [0001] The invention relates to a method for preparing a composite ball containing self-assembled microcapsules, in particular to a method for preparing a composite ball with an alkanol etherified amino resin as the wall of the microcapsule. Background technique [0002] Capsule technology is a technology in which film-forming materials wrap solids, liquids or gases to form tiny particles, which can protect the capsule core, control release, and achieve permanent solidification, which greatly facilitates the application range of the capsule core material. According to The particle size can be divided into: nanocapsules with a particle size of less than 1 μm, microcapsules with a particle size of 1-1000 μm, and macrocapsules with a particle size greater than 1 mm. Their application areas cover medicine, food, coatings, pesticides, adhesives, inks, and textile dyeing and finishing. [0003] At present, amino resin capsules often use amino resin prepolymers. By...

AI Technical Summary

Problems solved by technology

When using this method to prepare capsules, due to the influence of pH value, some emulsifiers will undergo polycondensation, crosslinking and solidification under the action of heat and catalyst acid, and the prepolymer will also self-assemble into small balls, which will affect the encapsulation efficiency. It brings great difficulties to the suction filtration and washing of the capsule suspension, which seriously limits its industrialization to a certain extent and affects its product quality.

[0004] In patent CN1513938A (a microcapsule-coated phase-change material and its preparation method), Wang Lixin, Ren Li, etc., use the phase-change material as the capsule core, and divide the aqueous solution of melamine-formaldehyde prepolymer into two equal parts. Add it dropwise to the emulsion with pH=4~5 for a few times, and raise the temperature to obtain microcapsules with double-layer capsule walls. If too much acid is added to the emulsion or too fast, the emulsifier will be solidified and cross-linked; and the water-soluble Melamine-formaldehyde resin will dissolve in the water phase, resulting in low capsule purity, self-polymer impurities, and complicated preparation process

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