Method for making stable, homogeneous melt solutions

A melt, stable technology used in the preparation of stable, homogeneous melt solutions, which can solve problems such as expensive
CN1726246AInactive Publication Date: 2006-01-25SHPP GLOBAL TECH BV
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
SHPP GLOBAL TECH BV
Publication Date
2006-01-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

Stable, homogeneous melt solutions are prepared at temperatures of 200 DEG C or less from solid mixtures comprising at least one diaryl carbonate, at least one high melting dihydroxy aromatic compound (mp>200 DEG C), a transesterification catalyst, and optionally a lower melting dihydroxy aromatic compound. Thus, a stable, homogeneous melt solution is obtained from a solid mixture comprising 4,4'-biphenol(mp 282-284 DEG C) at a temperature of about 200 DEG C using either diphenyl carbonate or bis(methyl salicyl) carbonate as the diaryl carbonate component. It is shown that formation of the stable, homogeneous melt solutions requires the presence of the transesterification catalyst when substantial amounts of the high melting dihydroxy aromatic compound are present in the initial solid mixture. Solid mixtures comprising a variety of high melting bisphenols; 4,4'-biphenol; 3,3,3,3'tetramethylspirobiindanbisphenol, and 4,4'-sulfonydiphenol are converted to stable, homogeneousmelt solutions at 200 DEG C, a temperature substantially below the melting points of the high melting bisphenols in their pure states.
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Description

Background technique

[0001] The present invention relates to the preparation of stable, homogeneous melt solutions useful for the preparation of homopolycarbonates and copolycarbonates.

[0002] Polycarbonate is widely used because of its combination of transparency, toughness, heat resistance, and plasticity. It is regarded as a relatively low-cost thermoplastic rate. The most widely used polycarbonate is bisphenol A polycarbonate, with hundreds of millions of pounds of bisphenol A polycarbonate produced and sold worldwide each year.

[0003] Polycarbonates, both homopolycarbonates and copolycarbonates, can be advantageously prepared in the absence of solvents, a process sometimes referred to as heating diaryl carbonate in the molten state in the presence of a transesterification catalyst. "melt method" of base esters and one or more bisphenols. This melt method offers certain advantages over the widely used interfacial method of polycarbonate preparation using a solvent, t...

Claims

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