Elastomeric compositions containing fluoropolymer blends

Abstract

Processable rubber compositions contain a vulcanized fluorocarbon elastomer dispersed in a thermoplastic matrix comprising a fully fluorinated polymer and a partially fluorinated polymer. The processing temperature is below the melting point of the fully fluorinated polymer. The compositions are made by combining a curative, uncured fluorocarbon elastomer, a fully fluorinated thermoplastic, and a partially fluorinated thermoplastic material, and heating the mixture at a temperature and for a time sufficient to effect vulcanization of the elastomeric material, while mechanical energy is applied to mix the mixture during the heating step. Shaped articles such as seals, gaskets, O-rings, and hoses may be readily formed from the rubber compositions according to conventional thermoplastic processes such as blow molding, injection molding, and extrusion.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a divisional of U.S. patent application Ser. No. 10 / 813,527 filed on Mar. 30, 2004, the disclosure of which is incorporated herein by reference.INTRODUCTION [0002] The present invention relates to fluorine containing elastomer compositions. [0003] Cured elastomers or rubbers have a variety of physical properties useful for applications in molded articles. Among the properties are a high degree of flexibility, elasticity, and resistance to compression set. As such they find use in a variety of applications, such as seals and gaskets. Uncured elastomers or rubbers are in the form of a resin or gum. To obtain a molded article with suitable elastomeric properties, the uncured resins are crosslinked or cured with a variety of crosslinking agents. [0004] For conventional elastomers, cure is generally carried out in a mold under conditions of temperature and pressure suitable for forming a cured or partially cured article. B...

AI Technical Summary

Benefits of technology

[0003] Cured elastomers or rubbers have a variety of physical properties useful for applications in molded articles. Among the properties are a high degree of flexibility, elasticity, and resistance to compression set. As such they find use in a variety of applications, such as seals and gaskets. Uncured elastomers or rubbers are in the form of a resin or gum. To obtain a molded article with suitable elastomeric properties, the uncured resins are crosslinked or cured with a variety of crosslinking agents.

Problems solved by technology

Because the curing reaction produces a thermoset material, conventional rubber compositions cannot be processed after the elastomer is cured.

A drawback of using fluorinated thermoplastics in such processable compositions is that their melting point is generally higher than the stability range of the cured elastomer.

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