Abstract: Polyacetal resins can selectively be reduced in terms of surface gloss by the addition of a core-shell polymer. The core-shell polymer which serves as the surface gloss reducing agent is one which has a rubbery polymer as its core, and a glassy vinyl copolymer having an oxygenic group (e.g., a hydroxyl or glycidyl group) as its shell. Preferably, the core-shell polymer is emulsion polymerized in sequential stages to form the core and shell polymers by use of an oligomeric surfactant. The core-shell polymer is most preferably present in the polyacetal compositions in an effective amount of between 1 to 50 parts by weight, based on 100 parts by weight of the polyacetal base resin.

Abstract: A slow-release composite having pyroglutamyl-histidyl-triptophyl-seryl- tyrosyl-D-leucyl-leucyl-arginyl-proline ethylamide or a salt thereof encapsulated in a polymer matrix and a process the same are herein disclosed.