Arkema France

Atofina

Exxonmobil Chemical Patents Inc.

Arkema Inc.

David Silagy

Philippe Bussi

Anthony Bonnet

Stefan B Ohlsson

Karine Loyen

Christophe Lacroix

Karine Triballier

Francois Beaume

Martin Baumert

Gérard Reignier

Thibault Montanari

Jose Teixeira Pires

Jean-Francois Agassant

Yves Demay

Francois H Chambon

Roparz Kervennal

Jocelyn Mauffrey

The invention relates to a method of producing a film comprising at least one layer of a thermoplastic fluoro-polymer and at least one layer of another polymer (A). The inventive method consists in using extrusion blow molding to coextrude a fluoro-polymer and polymer (A) which adhere to one another; with a layer of another thermoplastic polymer (B) such that it forms a layer which is adjacent to the fluoropolymer/polymer (A) layer According to the invention, the thermoplastic polymer (B) is incompatible with the fluoro-polymer and polymer (A) and has adequate extrudate behavior to support the layers of fluoro-polymer and/or polymer (A). Once the coextrudate has been cooled, by separating the layer(s) of (B), at least the film is recovered, said film comprising at least one layer of a polymer selected from among thermoplastic fluoro-polymers and polymers (A).

Method of producing films by means of coextrusion blow-moulding

The present invention relates to the use of films, formed from an adhesive layer and a layer (A), for coating articles made of a thermoset, the adhesive layer comprising, by weiqht: 0 to 60 parts of PVDE, 10 to 100 parts of functionalized PMMA, 0 to 50 parts of an acrylic elastomer and 0 to 4 parts of a UV absorber, the total making upparts, the layer (A) comprising, as main constituents, 0 to 100 parts of PVDF per 100 to 0 parts of PMMA, respectively. This film may be manufactured by coextrusion and is then fixed to the thermoset, for example by hot pressing. The invention also relates to an SMC (Sheet Moulding Compound) multilayer structure comprising, in this order: a backing film, a crosslinkable composition (the precursor of the thermoset), the above adhesive layer and the above layer (A).

Use of a film based PVDF, PMMA or a blend thereof for covering articles made of a thermoset

A structure made of a fluoropolymer layer and directly attached to one of its sides a tie layer based on a polyamide which results from the condensation of at least one diacid and at least one diamine of the following formula (1):in which Rrepresents H or -Z1-NHand Z1 represents an alkyl, a cycloalkyl or an aryl having up to 15 carbon atoms and Rrepresents H or -Z2-NHand Z2 represents an alkyl, a cycloalkyl or an aryl having up to 15 carbon atoms, it being possible for Rand Rto be identical or different. The tie resin may also be a copolymer having polyamide blocks and polyether blocks, the polyamide blocks resulting from condensation of at least one diacid and at least one diamine of formula (1). The invention also relates to a structure comprising a fluoropolymer layer, the tie layer and a substrate layer, respectively, as well as to a structure comprising a tie layer, respectively. This structure may be placed between two substrate layers and may be in the form of a sheet, film, profile or tube. It is particularly useful in the form of a tube for transporting gasoline between the tank and the injection device in motor-vehicle engines.

Structure comprising a fluoropolymer layer and a piperazine-based tie resin

A composition coextrudable with PVDF comprises in parts by weight: 20 to 40 parts of PVDF; 40 to 60 parts of PMMA; 5 to 18 parts of an acrylic elastomer; 1 to 4 parts of a UV absorber; the total making 100 parts. Coextruded films comprise a layer of the above coextrudable composition directly attached to the latter; and a PVDF-based layer comprising, as main constituents, 50 to 100 parts of PVDF per 50 to 0 parts of PMMA respectively. The PVDF layer may be in the form of two layers: one placed against the coextrudable layer and comprising, as main constituents, 50 to 90 parts of PVDF per 50 to 10 parts of PMMA respectively; and the other (also called the outer layer) comprising, as main constituents, 75 to 100 parts of PVDF per 25 to 0 parts of PMMA respectively. The resultant products are generally applied to substrates, e.g. as protective films.

Composition coextrudable with PVDF

Thermoformable multilayer film for the protection of substrates and objects obtained

The invention relates to a process for melt extruding a film layer of a thermoplastic olefin which comprises extruding the film having physical characteristics under process conditions selected by reference to the Draw ratio Dr and the Aspect ratio A such that draw resonance is avoided in which in addition the process conditions are defined by reference to the Deborah number such that the molten polymer is extruded at a Draw ratio of at least 30 in a high elasticity region at a &lgr;,value of characteristic time as defined herein of from 0.001 to 0.6 s, a Deborah number as defined herein in excess of 0.005 and an A value as defined herein lower than 0.8. Narrower ranges of these parameters may be defined for application of the invention to different polymer types.

Melt extrusion processes and films produced thereby

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Evreux, France

David Silagy