Small, oily, free-flowing, silky-smooth, talc-like, dry microcapsules and aqueous formulations containing them

摘要

This disclosure is directed to the preparation of dry microencapsulated product, having an oily core material with microcapsule cell wall materials having a first cell wall of gelatin/polyvinyl methylether maleic anhydride copolymer (PVMMA)/carboxymethylcellulose (CMC) which is prehardened (cross-linked) with a material selected from the group consisting of formaldehyde, glyoxal and glutaraldehyde to which there is grafted formaldehyde and resorcinol which is then crosslinked with formaldehyde and urea, and aqueous formulations containing them. Approximately 97% of these microcapsules have a size less than 100 and more characteristically having a particle size peak distribution of 30 to 40 microns (microcapsular diameter). These microcapsules contain less than approximately 3 wt. % free oil and more characteristically less than about 1 wt. % free oil (non-micro-encapsulated oil) and have less free (unreacted) formaldehyde which can be extracted with water, than do prior art microencapsulated emollient materials. The dry microcapsules of this invention are free-flowing and have a silky-smooth feeling similar to that of talcum powder.