Removal of excessive formaldehyde in microcapsule dispersion

Abstract

Abstract PURPOSE:To reduce excessive formaldehyde in a capsule dispersion with good efficiency, by adding a compound having a hydroxyoxo structure at the terminal of the carbon chain thereof and a hydroxylamino compound under an alkaline condition to perform reaction. CONSTITUTION:A compound having a hydroxyoxo structure at the terminal of the carbon chain thereof is used in a microcapsule dispersion in an amount of 0.4-40mol% based on the excessive formaldehyde in said dispersion under an alkaline condition with pH of 11-12.5 to be reacted with formaldehyde for a definite time and, thereafter, a hydroxylamine compound (e.g., hydroxylamine sulfate) is added in an amount of about 20-100mol%. As a result, excessive formaldehyde in the microcapsule dispersion can be reduced without generating discoloration or an unpleasant odor and damaging a capsule wall.

Inventors

• 👤 Masahisa Sakamoto
• 👤 坂本　昌央
• 👤 Eiichi Sugiyama
• 👤 杉山　栄一

Bibliographic Details