Method of injection (meth)acrylate copolymers with a tertiary ammonium groups

摘要

Method of production moulded parts by injection comprising the steps: a) melting a (meth)acrylate copolymer being present in admixture with 1 to 70 wt. % of a plasticiser and antiadhesive agent in a ratio of 1:1 to 1:20, and 0.05 to 5 wt. % of a mould-release agent , other conventional additives or adjuvants and optionally a pharmaceutical active substance be present in the mixture and before melting the mixture contains more than 0.5 wt. % of low-boiling ingredients with a vapour pressure of at least 190 kPa at 120 °C, b) degassing the mixture in the thermoplastic state at temperatures of at least 120 °C, thereby lowering the content of the low-boiling ingredients with a vapour pressure of at least 190 kPa at 120 °C to not more than 0.5 wt. % and c) injection the molten and degassed mixture containing at most 0.5 wt. % of the low-boiling ingredients with a vapour pressure of at least 190 kPa at 120 °C into the moulding cavity, whereby the moulding cavity being at a temperature which is at least 10 °C below the glass transition temperature of the (meth)acrylate copolymer, cooling the molten mixture and removing obtained moulded body from the mould.