Abstract: The invention relates to a method for treating a metal surface by carboxylation before forming, said metal being selected from zinc, iron, aluminium, copper, lead and the alloys thereof as well as copper-coated, aluminium-coated, galvanised steels. Said method is carried out in oxidising conditions in relation to the metal by bringing said metal into contact with an aqueous, organic or hydro-organic bath comprising at least one organic acid in free form or in salt form. The inventive method is characterised in that: the organic acid is a saturated or unsaturated aliphatic monocarboxylic or dicarboxylic acid; the organic acid is in solution and/or emulsion in the bath at a concentration greater than 0.1 mole/litre; the pH of the bath is acid.

Abstract: The present invention relates to an isotactic polypropylene obtained by metallocene catalysis, onto which is grafted a functional monomer. The invention also relates to a composition which may form part of the composition of a coextrusion binder. This composition according to the invention comprises isotactic polypropylene obtained by metallocene catalysis, grafted and then optionally diluted with at least one polyolefin (C1) and/or in at least one polymer of elastomeric nature (D). The invention also relates to a multilayer structure comprising a layer (L) comprising the above binder, and, directly attached thereto, a layer (E): which is polar, nitrogenous or oxygenated, such as a layer of polyamide resin, of ethylene/saponified vinyl acetate copolymer (EVOH) or of polyester; or of a mineral oxide deposited on a polymer such as polyethylene (PE), polyethylene terephthalate (PET) or EVOH; or which is metallic or metalloplastic.

Abstract: The present invention relates to a process for preparing sulphuric methacrylamide. The process can include adding sulphur trioxide and a second part of acetone cyanohydrin without sulfuric add to a reaction medium, after a first part of acetone cyanohydrin with sulphuric acid free of sulfur trioxide is mixed and dehydrated by heating.

Abstract: A thermosetting composition consists essentially of a mixture of (A) a polymer containing acid anhydride groups, (B) a molecular sieve being partially loaded with at least one amine, and (C) a filler capable of releasing water upon heating at a temperature above the processing temperature of the mixture of (A), (B) and (C). The processing temperature is chosen so as to be below the desorption temperature of the amine from the molecular sieve. The composition is particularly useful in making hot melt adhesives and sheetings of electric cables.

Abstract: Compositions are disclosed which comprise mixtures of at least one compound selected from silicone elastomers, bis-, tri- or higher polymaleimides and/or bis-, tri- or higher polycitraconimides, and at least one compound selected from p-phenylene-diamine based antiozonants, sulfur compounds capable of accelerating sulfur vulcanization of polymers capable of being crosslinked by sulfur and polysulfide polymers which when compounded into polymers curable by free radical initiators in the presence of free radical initiators permit substantially tack free surface cure of the polymers by decomposition of the free radical initiator in the presence of molecular oxygen. Compositions containing the above ingredients and at least one free radical initiator, curable compositions containing the combination and processes for making and using the compositions are also disclosed.

Abstract: The present invention relates to a coextrusion binder comprising: 5 to 30 parts of a polymer (A), itself comprising a blend of a polyethylene (A1) of relative density between 0.935 and 0.980 and of a polymer (A2) chosen from elastomers, very low-density polyethylenes and ethylene copolymers, the (A1)+(A2) blend being cografted with an unsaturated carboxylic acid; 95 to 70 parts of a polyethylene (B) of relative density between 0.930 and 0.950; the blend of (A) and (B) being such that: its relative density is between 0.930 and 0.950, the content of grafted unsaturated carboxylic acid is between 30 and 10,000 ppm, the MFI (melt flow index) measured according to ASTM D 1238 at 190° C./21.6 kg is between 5 and 100. This binder is particularly useful for petrol tanks of structure: HDPE/binder/EVOH or PA/binder/HDPE.

Abstract: An improved process for priming a metal surface to improve the adhesion to the surface of a resin coating possessing functional groups that react with epoxide groups, such as amide functionality containing polyamide resins.

Abstract: This process for the production of the methyl ethyl ketone cyanohydrin of formula (I) is characterized by the fact that hydrocyanic acid and methyl ethyl ketone are reacted in the presence of diethylamine as a catalyst.

Abstract: Multi-phase blends of VDF-based polymers are provided which are useful in a variety of applications such as wire and cable, pipe and liner applications, and rotational molding.

Abstract: New and novel copolymers of vinylidene fluoride and hexafluoropropylene containing up to 24% by weight hexafluoropropylene having lower DSC melting temperatures at 8 weight percent or greater nominal HFP content, and having improved solution clarity and fluidity, longer gel times and lower extractables than prior art vinylidene fluoride-hexafluoropropylene copolymers of comparable HFP content whose syntheses are disclosed in sufficient detail to duplicate, to novel compositions of matter and articles of manufacture containing such copolymers, processes for the preparation and use of the copolymers, of the compositions of matter containing such copolymers and of the articles of manufacture containing such copolymers are disclosed. Improved electrochemical cells based on the new and novel copolymers are particularly disclosed.

Abstract: The invention concerns a method for protecting metal products against corrosion, characterised in that it consists in applying directly on the metal products, that is without prior treatment, a composition consisting at least of a film-forming binder, at least a corrosion inhibiting additive reactive with metal and at least an oligomer additive bearing phosphonic acids. The inventive composition is characterised in that it comprises a film-forming binder, at least a corrosion inhibiting additive reactive with metal and at least an oligomer additive bearing phosphonic acids.

Abstract: The present invention comprises a transparent and partially fluorinated polymer which comprises three repeat units resulting from industrial monomers which are simple to access and which has a glass transition temperature of greater than 25° C., which polymer makes possible the preparation of articles, in particular of articles acting as guide or conductor for light in the region of the wavelengths of visible or near infrared type. This polymer is of use in the manufacture of optical fiber.

Abstract: The invention comprises a vinylene carbonate (VCA) copolymer having as comonomer chlorotrifluoroethylene (CTFE) or tetrafluoroethylene (TFE). This copolymer is transparent, making possible the preparation of objects acting as guide or conductor for light with wavelengths of visible or near infrared type. Furthermore, it exhibits a glass transition temperature of greater than 60° C. which is appropriate for the preparation of optical fibers.

Abstract: Vinylidene fluoride polymers are produced by using a C3-C5 hydrocarbon as a chain transfer agent in the free radical polymerization process.

Abstract: The present invention relates to a process for the radical polymerization or copolymerization of ethylene under high pressure in the presence of at least one polymerization initiating-controlling compound capable of providing, by decomposition under the polymerization or copolymerization conditions: at least one initiating free radical (Z) which carries at least one site for initiating the (co)polymerization; and at least one stable free radical (SFR) which carries at least one site exhibiting the stable radical state and which is stable under the polymerization conditions, with, in total, as many initiating sites as sites exhibiting the stable radical state.

Abstract: 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.

Abstract: A polypropylene fiber including greater than 50% by weight of a first isotactic polypropylene produced by a Ziegler-Natta catalyst, from 5 to less than 50% by weight of a second isotactic polypropylene produced by a metallocene catalyst and up to 15% by weight of a syndiotactic polypropylene (sPP).

Abstract: The invention concerns a method for preparing block copolymers comprising steps which consist in: polymerising a first monomer using an organolanthanide catalyst wherein said catalyst in the form of a hydride complex of a trivalent metal from the group of rare earths; then in polymerising at least a second monomer. The invention also concerns block copolymers whereof the blocks are polyolefins.

Abstract: Use of isotactic polypropylene homopolymers or copolymers in processes in which the polypropylene solidifies from a melt, wherein for enhanced speed of solidification of the polypropylene the polypropylene has a melt temperature and a crystallisation temperature not more than 50° C. less than the melt temperature resulting from the polypropylene having been produced using a metallocene catalyst component having the general formula: R″(CpR1R2R3)(Cp′Rn′)MQ2. Cp and Cp′ are a substituted cyclopentadienyl ring, and a sybstituted or unsubstituted fluorenyl ring, respectively. R″ is a structural bridge; R1 is a substituent on the cyclopentadienyl ring distal to the bridge. The distal substituent comprises a bulky group of the formula XR*a; X is chosen from Group IVA. M is a Group IVB transition metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or is a halogen.

Abstract: The invention relates to a continuous process for the manufacture of PVDF homopolymer or copolymer. The optional comonomer comprises a vinyl group polymerized by free radicals, and comprises at least one fluorine atom, a fluoroalkyl group or a fluoroalkoxy group, directly attached to this vinyl group. The invention also relates to PVDF homopolymers made by processes of the invention. The invention further relates to a process for deoxygenating a flow.