Process for production of polycarbonate resin pellets

Abstract

The invention provides polycarbonate resin pellets which are characterized in that: the content of impurities such as chlorine compound, etc. is extremely small, resin deterioration happens few, the polycarbonate resin pellets will not yellowing and appearance thereof is good, and the polycarbonate resin pellets can be used without resin additives. The present invention is a process for producing polycarbonate resin pellets, characterized by comprising the steps of: 1) using a polycarbonate resin having a specific powdery or granular form; 2) moving the polycarbonate resin in an inert gas atmosphere having an oxygen concentration of 3 vol% or less by allowing the polycarbonate resin to fall in the inert gas atmosphere 50 cm or more; 3) injecting a specified amount of water having an electrical conductivity of 30 [mu]S / cm or less in a kneading zone of an extruder; 4) sucking an vent inlet so as to render the vent inlet in a pressure-reduced state and, at the same time, adjusting the water content in the resin to 10-200 ppm; 5) introducing a strand-shaped molten resin that is extruded through a die into water having an electrical conductivity of 30 [mu]S / cm or less to thereby cool the molten resin; 6) cutting the strand at 70-130 DEG C to produce pellets each containing 10-200 ppm of water; and 7) allowing the pellets each having a water content of 10-200 ppm thus produced to further absorb water in a wet atmosphere, thereby adjusting the water content of the pellets to a value greater than the initial water content of the pellets and equal to or lower than 1300 ppm.

Description

Technical field [0001] The present invention relates to a method for manufacturing polycarbonate resin pellets, and more specifically to a method for manufacturing polycarbonate resin pellets. The polycarbonate resin pellets contain very little impurity content such as chlorine compounds, less resin degradation, and no spreading. Yellow, the pellets have good appearance and can be used without resin additives. Background technique [0002] As a general engineering plastic, polycarbonate resin has excellent transparency, impact resistance, heat resistance, dimensional stability, etc. Because of its excellent properties, it is widely used in electrical, electronic, office automation equipment parts, mechanical parts, and vehicle parts. Used in the field. [0003] In electrical and electronic equipment, various electrical and electronic equipment components such as silicon wafers, optical disk substrates, hard disks for data storage, optical storage optical disks, IC chips, and high-...

AI Technical Summary

Problems solved by technology

However, only with these methods, the cleanliness cannot be said to be sufficient in shipping boxes and the like whose cleanliness requires a high level, and a method for efficiently producing polycarbonate resin molding materials having a high level of cleanliness is desired.

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