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ADDITIVE PROCESSING OF FLUOROELASTOMERS

IP.com Disclosure Number: IPCOM000249476D
Publication Date: 2017-Feb-28

Publishing Venue

The IP.com Prior Art Database

Abstract

Provided are methods of producing a shaped fluoroelastomer articles. The methods include subjecting a composition comprising a fluoroelastomer to additive processing in an additive processing device. Also provided are articles obtained with the methods and 3D-printable compositions.

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ADDITIVE PROCESSING OF FLUOROELASTOMERS

ABSTRACT

Provided are methods of producing a shaped fluoroelastomer articles. The methods include

subjecting a composition comprising a fluoroelastomer to additive processing in an additive processing

device. Also provided are articles obtained with the methods and 3D-printable compositions.

BACKGROUND

Fluoropolymers are widely used as raw materials for their chemical inertness, in particular for

articles requiring low friction properties and /or inertness to chemical reactivity, heat, or both.

Fluoropolymers are typically classified into thermoplastics, non-melt processable fluoropolymers

and elastomers (sometimes also referred to as fluororubbers).

Fluorothermoplastics can be processed by conventional melt shaping methods, such as injection

molding and extrusion. Fluorothermoplastics typically are copolymers of tetrafluoroethylene (TFE) with

one or more other perfluorinated, partially fluorinated or non-fluorinated comonomers. Copolymers of

TFE and perfluorinated alkyl or allyl ethers are known in the art as PFA’s (perfluorinated alkoxy

polymers). Copolymers of TFE and hexafluoropropylene (HFP) with or without other perfluorinated

comonomers are known in the art as FEP’s (fluorinated ethylene propylene). Copolymers of TFE, HFP

and vinylidenefluoride (VDF) are known in the art as THV. Other types of melt-processable

fluoropolymers are based on vinylidenefluoride homo- or copolymers, known in the art as PVDF.

Copolymers of TFE and ethylene are known as ETFE.

Non-melt processable fluoropolymers include homopolymers of TFE or copolymers of TFE with

other copolymerizable perfluorinated monomers, wherein the amount of comonomers is limited to less

than 1 %wt. Such TFE homo-and copolymers are referred to in the art as PTFE. PTFE has such a high

melt viscosity that it cannot be processed by conventional melt processing techniques such as extrusion,

injection molding or blow molding. Instead PTFE articles typically are produced by paste extrusion, or by

sintering to produce blocks or billets which are then shaped into articles. For example by skiving, turning,

machining (i.e., substractive methods where material is removed to shape articles).

Fluoroelastomers, typically are copolymers of TFE and at least one other fluorinated comonomer,

typically an alpha-olefin and have a glass transition temperature below 25°C. Most commonly used

comonomers include HFP and VDF or perfluorinated alkyl vinyl ethers (PAVE’s). Fluoroelastomers are

curable into a three-dimensional network to produce rubber-like materials (also called fluororubbers).

Fluoroelastomer articles are typically shaped by die cutting or injection molding.

In WO2007/133912 A2 an additive manufacturing process for special thermoplastic

fluoropolymers (PVDF and PCTF) are described but examples are not provided. In CN103709737 A and

CN 105711104 A methods for 3D printing are described where the use of PTFE is mentioned. The

materials are processed by irradia...