초록 ▼

Increasing the endcap level to a level greater than about 90% for Optical Quality (OQ) Melt Polycarbonate significantly reduces the as-molded static charge for injection molded parts for Optical Disc applications. The use of resins with higher endcap levels in combination with antistatic additives p

Increasing the endcap level to a level greater than about 90% for Optical Quality (OQ) Melt Polycarbonate significantly reduces the as-molded static charge for injection molded parts for Optical Disc applications. The use of resins with higher endcap levels in combination with antistatic additives provides a highly robust formulation suitable for even the most demanding emerging formats as Digital Versatile Disc (DVD) and in all commercial Optical media molding machines. Thus, optical quality polycarbonates are prepared by performing a base-catalyzed polymerization of a diaryl carbonate and a dihydric phenol under conditions effective to produce a polycarbonate product having an endcap level of 90% or greater.

대표청구항 ▼

[ We claim:] [1.]1. A method for preparing optical quality polycarbonate comprising melt polymerizing a reaction mixture comprising diaryl carbonate and a dihydric phenol while manintaing conditions effective to produce a level of endcapping of at least 90%, wherein the level of at least 90% is prod

[ We claim:] [1.]1. A method for preparing optical quality polycarbonate comprising melt polymerizing a reaction mixture comprising diaryl carbonate and a dihydric phenol while manintaing conditions effective to produce a level of endcapping of at least 90%, wherein the level of at least 90% is produced by a method selected from the group consisting of providing the diaryl carbonate and a dihydric phenol in the reaction mixture at a starting ratio of at least 1.05, addition of a monofunctional endcapping reagent, or a combination comprising at least one of the foregoing methods.