Blends of polyphenylene ether sulfone and silicone polyester carbonate

Abstract

Disclosed herein is a composition comprising a polyphenylene ether sulfone and a resorcinol based silicone aryl polyester carbonate copolymer wherein greater than or equal to 50 mol % of copolymer repeating units are ester units derived from resorcinol, based on the total molar amount of all repeating units in the polymer and wherein the blend has less than 1 weight percent polycarbonate, based on the total weight of the composition, has FAR 25.853 peak heat release of less than 60 KW / m2 and time to peak heat release of greater than or equal to 120 seconds.

Description

BACKGROUND[0001]Disclosed herein are blends of polyphenylene ether sulfone and silicone polyester carbonate, methods for making the blends, and articles derived from such blends. The blends have a particularly advantageous combination of properties.[0002]There has long been interest in developing thermoplastic resins that can resist burning. A specific area of concern is in developing plastics for transportation applications, such as rail cars and airplanes. Various evaluation techniques have been developed to test the effectiveness of such materials, for instance Federal Aviation Regulation (FAR) 25.853. In this test, sometimes referred to as the Ohio State University (OSU) rating, the time for a sample to reach peak heat release, the amount of energy released after 2 minutes and the peak heat release energy are measured. Lower peak heat release values and longer time to reach peak heat release are desirable.[0003]Polyphenylene ether sulfones (PPSU) are well known engineering therm...

AI Technical Summary

Benefits of technology

This patent describes a composition made of a specific material called polyphenylene ether sulfone and a special silicone aryl polyester carbonate copolymer. The composition has certain physical properties like being strong and having a slow heat release. It can also have specific ratios of different types of material that make up the composition. The composition does not contain any polycarbonate, which is another material that can be added to it. The patent only describes the technical features of the composition, but there may be other ways to make this material that have different properties.

Problems solved by technology

PPSU resins have good flame resistance, but in terms of the very demanding requirements for large fire resistance, such as in aircraft and rail interiors (for example FAR 25.853 (d)) they do not meet the combined requirements of a 2 minute heat release below 55 kilowatt minutes per square meter (KW-min / m2) and peak heat release below 55 kilowatts per square meter (KW / m2).

The PPSU polymers also have an exceptionally high impact strength without rubber modification, however in many applications such as transportation and electronic applications, their high melt viscosity makes them difficult to mold into large thin walled parts.

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