PURPOSE: To provide a thermoplastic corrosive hydrolytically degradable copolymer obtained by bonding a specific diorganopolysiloxane block and a polyester block by a specific bridge and used for the sustained release object of an effective substance, having sufficient mechanical properties and showing easy shaping properties.
CONSTITUTION: A diorganopolysiloxane-polyester block copolymer has the following structure: that is, 1-99 wt.% of the diorganopolysiloxane block represented by formula I and 1-99 wt.% of the polyester block represented by formula II are contained and the blokes I, II are together bonded by a bridge represented by formula III. In formulae I, II, R is a same or different monovalent org. group and Y is the divalent org. group bonded to a silicone atom through an SiC bonding group and Z is a divalent hydrocarbon group,(m) is 1-500, and p1, p2, r1 and r2 are 0-10,000 but r1+r2+p1+p2 is less than 1,000 but larger than 1. In formula III, B is a divalent org. group or org. silicon group capable of containing doorganopolysiloxane block represented by formula IV (wherein R1 is R and (n) is same as (m), it being possible for R and R1, and (m) and (n) to have identical or different meanings).
RAFUAERU JIYORUDA
YUGU PORUTO
KURISUTEIAN PURIYUDONMU
JIYORUJIYU SOOBE
GISUREENU TORE
| JP41005275A |
| EP0299730A2 | 1989-01-18 |