Abstract: A process for the emulsion polymerization in the presence of a stable free radical of at least one monomer which can be polymerized by the radical route, which emulsion comprises a liquid aqueous phase and a liquid organic phase, the aqueous phase comprising at least 50% by weight of water and the liquid organic phase comprising more than 50% by weight of monomer(s) to be polymerized. The invention results, by a rapid controlled polymerization process, in a latex of polymer particles, it being possible for the polymer to comprise acrylate and/or methacrylate blocks.
Abstract: A gas-impermeable elastic membrane including a co-polymeric gas-impermeable film including OH groups, positioned between two layers of a co-polymer containing blocks of polyamides and of polyesters, with a rubber coating on at least one of the two layers, as well as a method of manufacturing the membrane.
Type:
Grant
Filed:
February 17, 1998
Date of Patent:
February 26, 2002
Assignee:
Elf Atochem S.A.
Inventors:
Yves Germain, Jean-Luc Beal, Christophe Le Roy
Abstract: The invention relates to a process comprising a stage of polymerization or copolymerization of at least one polymerizable or copolymerizable monomer by a radical mechanism in the presence of a stable free radical and of an initiator of formula:
R1—O—O—R2
wherein R1 and R2, which can be identical or different, represent an alkyl, aryl, alkylaryl or aralkyl radical comprising, for example, from 1 to 20 carbon atoms. The process is fast, allows the initiator to act more efficiently and results in polymers or copolymers exhibiting a low yellowing index.
Type:
Grant
Filed:
May 9, 1997
Date of Patent:
February 12, 2002
Assignee:
Elf Atochem S.A.
Inventors:
Denis Bertin, Bernard Boutevin, Pascal Nicol
Abstract: A frontage element including a support and a panel, the panel including at least two fixing parts fixed to the support and a generally plane wall extending between the two fixing parts. At least one of the fixing parts is set back from the plane of the wall and is deformable so that the wall is free to move parallel to itself relative to the support if the temperature of the panel is modified.
Type:
Grant
Filed:
June 10, 1999
Date of Patent:
January 22, 2002
Assignee:
Elf Atochem S.A.
Inventors:
Marc Ginet, Michel Le Feron De Longcamp
Abstract: Process for preparing antistatic acrylic polymers wherein the acrylic monomers are polymerized in suspension, said acrylic monomers contain dissolved the antistatic additives selected from the following ones:
CnH2n+1CO—N(CH2CH2OH)2 (1)
wherein n is an integer ranging from 9 to 13;
Cn′H2n′+1N(CH2CH2OH)2 (2)
wherein n′ is an integer ranging from 8 to 14;
CH2(OR1)CH(OR2)CH2(OR3) or C(CH2OR1)(CH2OR2)(CH2OR3)(CH2OR4) (3)
wherein R1, R2, R3, R4 equal to or different from each other, are H or R, wherein R is a saturated or unsaturated C12-C18 alkylcarboxylate, preferably saturated or monounsaturated C18.
Type:
Grant
Filed:
July 21, 1999
Date of Patent:
December 25, 2001
Assignee:
ELF Atochem S.A.
Inventors:
Cristiano De Marco, Fabio Giberti, Lorenzo Poggi
Abstract: The initiation system comprises (1) at least one silylated initiator and (2) at least one alkaline metal alcoholate as ligand. The silylated initiator may be monofunctional and selected in particular from among the compounds of Formula (I) or difunctional and selected in particular from among the compounds of Formula (II):
wherein R1, R2, R3 each independently represent a C1-C8alkyl radical, linear or branched; R4 is a linear or branched C1-C8alkylene radical; M is an alkaline metal or alkaline earth metal (valence q of 1 or 2); R5 and R6 each independently represent an alkyl radical, linear or branched, at C1-C8; R7, R8 each independently represent a C1-C8alkylene radical, linear or branched; M′ is an alkaline metal. Application is to the preparation of (meth)acrylic (co)polymers.
Type:
Grant
Filed:
April 10, 1998
Date of Patent:
November 20, 2001
Assignee:
Elf Atochem S.A.
Inventors:
Christophe Navarro, Axel H. E. Müller, Andreas R. Maurer, Robert Jerome, Thomas Zundel
Abstract: Esters of formula:
HS—X—COOR
in which X denotes a C1-C4 alkylene radical and R a C1-C18 alkyl radical, are prepared by reaction of a hydrosulphide with the corresponding halocarboxylic ester:
Y—X—COOR
where Y denotes a chlorine or bromine atom. The reaction is performed under a hydrogen sulphide pressure of at least 10 bars absolute, and preferably in an anhydrous or substantially anhydrous alcoholic medium.
Abstract: The invention concerns a diaphragm chlor-alkali electrolysis cell comprising a cover, a conductive base for supporting the anodes and a cathode in the form of a box provided with internal wall, external wall and tubular fingers made of a mesh or perforated sheet covered with a porous diaphragm. One or more copper sheets for electric current distribution are fixed to the cathode external walls. The connection between the copper sheets and the cathode external walls is made by means of bolts with the interposition of a conductive and deformable element provided with residual elasticity under compression. The weldings for the assembling of the cathode walls are free from internal stresses.
Abstract: The present invention relates to a pressure-sensitive hot-melt adhesive composition characterized in that it includes a) at least one ethylene-alkyl acrylate copolymer, b) a tackifying resin and c) optionally a diluent and/or a stabilizer and/or a wax. Such a composition may be employed advantageously in the field of hygiene, especially for the adhesive bonding of disposable nappies and of catamenial liners.
Abstract: Mixed fluorination catalyst comprising one or more nickel and chromium oxides, halides and/or oxyhalides deposited on a support composed of aluminium fluoride or of a mixture of aluminium fluoride and alumina, characterized in that the weight of nickel/weight of chromium ratio is between 0.08 and 0.25, preferably between 0.1 and 0.2.
Type:
Grant
Filed:
December 4, 2000
Date of Patent:
October 2, 2001
Assignee:
Elf Atochem S.A.
Inventors:
Philippe Bonnet, Eric Jorda, Eric Lacroix
Abstract: The present invention relates to a latex containing two populations of particles of polymers based on vinyl chloride. Other subjects of the present invention are processes for producing this latex and its use in the manufacture of fluid plastisols which are stable on storage.
Type:
Grant
Filed:
August 27, 1997
Date of Patent:
October 2, 2001
Assignee:
Elf Atochem S.A.
Inventors:
Philippe Espiard, Richard Peres, Benoit Ernst
Abstract: The invention relates to a coextrusion binder obtained by grafting a mixture of a copolymer of ethylene and of an elastomer of EPR type with an unsaturated carboxylic acid anhydride or its derivatives. The grafted mixture is optionally diluted in another copolymer of ethylene. The binder is useful in preparing polyolefin/binder/polyamide or EVOH structures.
Abstract: For the stripping of photoresists, the invention proposes to use a mixture of dimethyl sulphoxide DMSO) or N-methylpyrrolidone (NMP) and 3-methoxypropylamine (MOPA).
Advantageously, a little water and a corrosion inhibitor, such as sodium tolyltriazolate, are added to the mixture.
Abstract: The invention relates to a coated metal surface including, successive, at least one layer of polyurethane and at least one layer of thermoplastic polymer, it being possible for a binder to be placed between the polyurethane and the thermoplastic polymer. The invention is useful for covering pipers, electrical cables, telecommunication cables and stay wires.
Type:
Grant
Filed:
September 2, 1999
Date of Patent:
September 18, 2001
Assignee:
Elf Atochem S.A.
Inventors:
Maxime Deroch, Evelyne Bonnet, Jean-Jacques Flat
Abstract: The present invention relates to a process for obtaining a solid catalyst of general formula (I):
[(Mg2+)1−x(Al3+)x(OH−)2]x+[(OH−)x]x−(H2O)n (I)
with 0.20≦x≦0.33 and n<1.
Abstract: In a process for the continuous preparation of mono- and/or bis(mono- and/or di- and/or trichloromethyl) benzenes by gradual chlorination of the corresponding mono-or dimethylbenzenes in several reactors in cascade, the first reactor has a greater volume than each of the other reactors.
Abstract: A building frontage including first frontage elements fixed to the building each including a cellular core and second frontage elements. The first and second frontage elements are arranged in substantially the same plane. The second frontage elements are fixed only to the first frontage elements.
Type:
Grant
Filed:
June 18, 1999
Date of Patent:
July 3, 2001
Assignee:
Elf Atochem S.A.
Inventors:
Marc Ginet, Michel Le Feron De Longcamp
Abstract: The invention relates to a multilayer structure comprising a layer of a binder either containing a hydroxyl function or containing an epoxy function or alternatively consisting of an ethylene/alkyl (meth)acrylate copolymer and, directly attached thereto, a layer of polyketone.
The structure may also comprise, on the binder side and directly attached thereto, either a layer of thermoplastic polymer such as polyethylene or a layer of rubber or a metal layer.
The invention is useful for manufacturing packaging, bottles or pipes.
Abstract: For the preparation of lactams comprising 6 to 12 carbon atoms from the corresponding cycloalkanone oximes by rearrangement according to the Beckmann reaction in the presence of acid, the process is characterized in that use is made of methanesulphonic acid.