Melt polycarbonate catalyst system

A polycarbonate, melt polymerization technology, applied in the field of polycarbonate preparation, can solve problems such as performance degradation

Inactive Publication Date: 2004-04-28
SABIC GLOBAL TECH BV
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  • Abstract
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All material from the quenching process remains in the

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  • Melt polycarbonate catalyst system
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Embodiment Construction

[0011] The invention provides a kind of polycarbonate preparation method, this method comprises under melt polymerization reaction condition in molecular formula A x + MF 6 -x contacting a diaryloxy compound and a dihydric phenol compound in the presence of a compound of , optionally in the presence of a cocatalyst selected from tetraalkylammonium and tetraalkylphosphonium salts,

[0012] where A is an alkali metal or an alkaline earth metal;

[0013] M is a transition metal of group IVA or VA, or M is a p-block metal of IIIB, IVB or VB;

[0014] x is 1, 2 or 3.

[0015] In a preferred embodiment, A is selected from sodium, potassium, cesium, lithium, barium or calcium. In a further preferred embodiment, M is a metal cation selected from silicon, tin, germanium, zirconium, strontium, aluminum, niobium and titanium.

[0016] Particularly preferred catalysts include Na 2 SiF 6 、Na 2 SnF 6 、Cs 2 SiF 6 、Cs 2 SiF 6 、K 2 TiF 6 、Na 2 GeF 6 、Na 2 ZrF 6 、Na 2 SbF ...

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Abstract

This invention provides a method for preparing polycarbonates, which utilizes polycondensation catalysts of the formula Ax+MF6-x, wherein A is an alkali metal or alkaline earth cation; M is a transition metal of group IVA or VA, or M is a p-block metal of group IIIB, IVB or VB; and x is 1, 2, or 3. We have found that this new class of catalysts provide excellent polymerization rates for the preparation of Bisphenol A polycarbonate from the melt polymerization of diphenyl carbonate and Bisphenol A. Moreover, the catalysts of the invention were found to be very selective in substantially reducing the level of branching side reaction, i.e., formation of Fries product, normally associated with the melt polycarbonate process.

Description

Background of the invention [0001] The present invention relates to a process for the preparation of polycarbonates by, for example, transesterification between diaryl carbonates and aromatic dihydroxy compounds. In particular, the present invention relates to melt polymerization reactions for the preparation of polycarbonates and novel polycarbonate catalysts containing alkali metals and transition metals. [0002] A number of catalytic systems have been tested for polycarbonate melt polymerization. Most of these methods require either various co-catalysts or the subsequent addition of a catalyst quencher to ensure polymer stability. The demand for high-purity, high-performance thermoplastic resins requires a reduction in the level of residual impurities in the final resin product. Optical performance (OQ) grade polycarbonate resins require very low levels of residual impurities, and this need is particularly acute. One way to eliminate residual solvent impurities, particu...

Claims

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Application Information

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IPC IPC(8): C08G64/20C08G64/30
CPCC08G64/307
Inventor J·P·莱蒙P·J·麦克洛斯基O·P·西克洛文
Owner SABIC GLOBAL TECH BV
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