Method for microencapsulating blowing agents and related products

摘要

A method for microencapsulating a core material, such as a blowing agent, in a single shell which has demonstrated to be challenging to microencapsulate as an individual component with a single-shell wall deposition using conventional techniques. Single-shell microcapsules of the blowing agent can be formed, minimizing steps involved in the present microencapsulation technique. Also, microcapsules formed by this method provide increased performance in end-use products, including but not limited to characteristics such as product shelf-life, ease of use, and greater expansion properties. A method of making a coating formulation including the microcapsules is further provided, as well as a fastener including the coating.

主权项

1. A method for producing a single shell microcapsule having a reactive core comprising:
preparing a mixture comprising:
providing a reactive core material in the form of a blowing agent, the blowing agent being insoluble in water;mixing the blowing agent with a protective secondary core material and water to produce a mixture, the protective secondary core material being insoluble in water, the blowing agent and the protective secondary core material being chemically non-reactive with one another, the protective secondary core material being miscible with the reactive core material, the blowing agent being more hydrophobic than the protective secondary core material;allowing the protective secondary core material to at least one of protect and surround the more hydrophobic blowing agent, with the difference in hydrophobicity between the blowing agent and the protective secondary core material driving the protection and surrounding of the blowing agent so that the presence of the blowing agent is at least one of minimized and non-existent at a droplet or aqueous interface; preparing a prepolymer solution including a shell material separately from the mixture; admixing the mixture and the prepolymer solution so that the shell material microencapsulates the protective secondary core material and the reactive core material therewithin, thereby forming a slurry including a plurality of single shell microcapsules, each of the single shell microcapsules containing the reactive core material surrounded by the protective secondary core material and the shell material, which is exterior to the protective secondary core material and at least one of polymerized and cross-linked; rinsing the plurality of single shell microcapsules; and drying the plurality of single shell microcapsules to form a free flowing powder.