High-intensity urea-formaldehyde resin microcapsule and preparation method thereof

Abstract

The invention relates to a high-intensity urea-formaldehyde resin microcapsule. Titanium dioxide or silicon dioxide inorganic nanoparticles with particle diameter of 10 to 50 nm are doped in the wall material of the microcapsule. A preparation method of the high-intensity urea-formaldehyde resin microcapsule comprises the following steps of: mixing urea and formaldehyde according to a molar ratio of the urea to the formaldehyde of 1:1.75; adjusting the pH value to 8.5 to 9.0; stirring at the constant temperature of between 70 and 75 DEG C for 1 hour; diluting by adding distilled water to obtain urea-formaldehyde prepolymer solution with mass concentration of 35 to 60 percent; taking 10 to 20 milliliters of the urea-formaldehyde prepolymer solution and adjusting the pH value to 4.0 to 4.2; reacting at the temperature of between 23 and 26 DEG C for 1 hour to obtain water-soluble urea-formaldehyde resin; dispersing the inorganic nanoparticles into an oil phase to prepare 0.04 to 0.2 mass percent of inorganic particle dispersion liquid; adding 40 milliliters of 7.3 mass percent of deionized water solution of a system modifier into the water-soluble urea-formaldehyde resin; adding 4.5 milliliters of inorganic particle dispersion liquid dropwise under stirring to form emulsion and then adjusting the pH value to 3.0 to 3.5; reacting at the temperature of between 23 and 26 DEG C for 1 hour; adding 0.3 to 3 grams of curing agent; heating the product to 45 to 50 DEG C; performing heat-preserving reaction for 2 hours; and performing suction-filtration and drying to obtain the urea-formaldehyde resin microcapsule, of which the wall material is doped with the inorganic nanoparticles.

Description

1. Technical field [0001] The invention belongs to the technical field of fine chemicals and microcapsules, in particular to a high-strength urea-formaldehyde resin microcapsule and a preparation method thereof. 2. Background technology [0002] A "core-shell" structure formed by wrapping dispersed solid, liquid, gas or their mixture (core material or capsule core) in natural or synthetic polymer materials or inorganic materials (wall material or capsule wall) Tiny containers, called microcapsules. Microcapsule technology began in the 1930s, but it was widely used in production after NCR Corporation of the United States prepared oil-containing gelatin microcapsules in 1953 and used them for carbonless copy paper. Because microcapsule products have obvious characteristics in the isolation and protection of active components, sustained release, and targeted drugs, they have attracted people's attention since their inception. As a commercial means with excellent performance...

AI Technical Summary

Problems solved by technology

Solve the defects of poor sealing of urea-formaldehyde resin microcapsules, easy collapse and damage after drying, and solve the difficulties of complicated preparation process, difficult to control, and harsh reaction conditions

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