Arkema France

Dehondt Technologies

Akrema France

Marc Audenaert

Gilles Hochstetter

Quentin P Pineau

Denis Huze

Thierry Briffaud

Sébastien Taillemite

Jean-Charles Durand

Emmanuel Rastelletti

Guy Dehondt

Edouard Philippe

The present invention relates to the field of thermoplastic composite materials. Specifically, the invention relates to a fluorinated, flame-retardant thermoplastic composition, to the prepreg prepared from said composition, to the composite material containing said prepreg, to the methods enabling manufacture, and to the uses of said material. The invention also relates to the use of a thermoplastic prepreg for manufacturing fire-resistant composite materials.

Thermoplastic composition and prepreg, composite material made of said prepreg, and uses of said composite material

The present invention relates to a method for producing a conductive composite material, as well as the composite material capable of being obtained by said method. The conductive material is obtained from a composite polymer matrix, which is formed by aggregation of composite conductive particles consisting of particles of a polymer matrix, having a diamter d50 of between 1 and 4000 &#x3bc;m, coated with a layer of electrically conductive material consisting of at least one metal. The ratio of the thickness of the conductive layer to the diameter d50 of the polymer matrix particles is between 0.0025:100 and 1.5:100, said thickness being less than 300 nm.

Method for producing a composite conductive material and composite material obtained in this way

A method for impregnating strands or strips of natural fibers, using the following successive steps: i) the impregnation of the strands or strips by immersion in a bath containing a fine aqueous polymer dispersion; followed by ii) the drying of the strands or strips using a heating system, with the progressive elimination of the water and the gradual melting of the polymer, and the coating of the strands or strips and the molten polymer incorporated into the core of the strands or strips as a binder between the fibers; iii) optionally, the forming of the treated strands or strips into their final shape; and iv) the cooling of the treated strands or strips. The aqueous polymer dispersion comprises at least one semi-crystalline or amorphous polymer and, in the case of an amorphous polymer, has a Tg varying between 50&#xb0; C. and 175&#xb0; C.

Method for impregnating natural fibres with a polymer in aqueous dispersion and use of said fibres in composite materials

The use of an aqueous polymer dispersion including at least one amorphous polymer having a Tg varying between 55&#xb0; C. and 175&#xb0; C. or a semi-crystalline polymer having a melting point varying between 70&#xb0; C. and less than 220&#xb0; C., the weight concentration of the polymer in the dispersion varying between 5 and 50%, with the polymer particles having an average size of less than 10000 nm, as a binder for impregnating strands or strips of natural fibers, in particular flax fibers, with said polymer being incorporated in the core of the fiber bundle forming the strand or strip and thereby binding the fibers together.

Use of a fine aqueous polymer dipersion for the impregnation of natural fibres

A method of producing a composite material, comprising an assembly of natural fibers, impregnated with an amorphous or semi-crystalline thermoplastic polymer, said method including: i) a step of impregnating said assembly with a precursor composition in the molten state and including: a) at least one prepolymer P(X)n of said thermoplastic polymer, having a molecular chain P having, at the ends of same, n reactive functions X, with n ranging from 1 to 3, in particular n being 1 or 2, and preferably 2 b) at least one chain extender Y-A-Y including reactive functions Y with at least one of said functions X ii) a step of polymerization by mass (poly)addition, in the molten state, of said prepolymer with said chain extender with: said thermoplastic polymer being the result of said polymerization by mass polyaddition and said impregnation i) and polymerization ii) taking place at a temperature lower than 250&#xb0; C.

Thermoplastic composite material made from natural fibers

The invention provides a self-adhesive composition in powder form for the coating of metallic substrates, composed of homopolyamide (A) selected from PA11 and PA12, copolyamide (B), calcium carbonate and, optionally, at least one component selected from a pigment or dye, an anti-crater agent or spreading agent, a reductant, an antioxidant, a reinforcing filler, a UV stabilizer, a fluidizing agent and a corrosion inhibitor, said composition being devoid of silane-type adhesion promoter or of an adhesion promoter containing an epoxy, alcohol and/or carboxylic acid function, or derivatives thereof, and having a dry-state modulus and/or a wet-state modulus of greater than or equal to 2200 MPa [Standard NF EN ISO 527]. The invention also relates to a composite material comprising a metallic substrate directly coated with a coating film resulting from the melting of said composition, the adhesion of the coating film to the metallic substrate being greater than 3 after 2000 hours of salt fog before and after drying, in accordance with Standard NFT 58-112.

Polyamide-based high-performance self-adhesive powder without adhesion promoter

The invention concerns to the use of a powder comprising 99.95 to 95% of at least one polyamide and 0.05 to 5% of at least one silane for coating metals. This powder may be prepared by simple dry blending of the constituents. The silane can also be added to the molten polyamide in a mixing device and the resulting product reduced to powder. The addition of silane makes it possible to significantly improve electrostatic application by preventing a substantial portion of the powder from falling off during the electrostatic discharge which follows application, while providing lasting adhesion between the coating and metal. Advantageously, the silane is chosen from aminopropyltriethoxysilane and aminopropyltrimethoxysilane. The invention also concerns a method of coating an object with a film resulting from melting a thin layer of the powder.

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Bernay, France

Marc Audenaert