Abstract: The relationship between the average degree of roughness of the faces of rough appearance, expressed in microns, and the percentage by weight of units derived from vinyl acetate in the copolymer of which the film consists is greater than 0.019.The film is extruded in the form of an extruded sleeve which is cooled in the die by a circulation of a coolant fluid whose temperature T satisfies the relationship: ##EQU1## in which Tc is the temperature at which the Napierian logarithm of the relationship between the length at break and the initial length of a test specimen of the copolymer has a value of 87% of its value at 180.degree.Tm is the mean temperature of the copolymer as it leaves the diea is equal to 0.24G is given by the relationship .rho..times.Cp.times.V.times.H.sup.2 /.lambda..times.Lin which.rho. is the density of the copolymerCp is the specific heat of the copolymerV is the mean flow velocity of the copolymer through the extrusion dieH is the height of the gap between the core and the extrusion die.

Abstract: The valve, mounted on a vent pipe, allows the passage of gas in both directions, but prevents any escape of liquid fuel. The valve comprises a closed containment 7 equipped with a lower inlet port 8 and with an upper outlet port 9 which are connected to the vent pipe, a stationary circular inner cup 10 kept spaced from the inner wall of the containment and from the inlet port, a vertically displaceable assembly surmounting the cup and comprising a float 13 and a needle 16 which is equipped with a gasket 17 and is fixed to the float and which, in the high position of the assembly, can close off the outlet port 9, and means 11, 14, 15 for causing an upward displacement of the assembly as a result of an inclination of the containment 7. Furthermore, the annular space between the cup 10 and the inner wall of the containment 7 is profiled so as to form a Venturi tube 18 which is kept in relationship via at least one passage 20 with the volume 19 located between the cup 10 and the base of the float 13.

Abstract: A process for the preparation of a polymer which is electrically conductive and which is based on polythiophene, the process including polymerizing thiophene in a reaction medium including thiophene, from 2.5 to 20 moles of an anhydrous ferric salt per mole of thiophene, from 0.04 to 1 liter of an alkyl halide per gram of thiophene, and from 0.1 to 5% by weight of water introduced into the reaction medium based on the amount of alkyl halide.

Abstract: This invention relates to operator DNA specific for the repressor of .phi.105 and to the use thereof. The sequence of the operator DNA is 5'-GACGGAAATACAAG-3', 5', GTCGGAAATACAAT-3', 5'-GACGAAATTCAAG-3' or 5'-GTCGTGAATACCAT-3.

Abstract: Moulding compositions comprising a polyolefin, cellulose fibres and an unsaturated organosilane exhibiting a tensile elasticity modulus (E), measured at 100.degree. C., higher than 1250 MPa and a ratio G'/G" of their modulus G', representing their elastic response, to their loss modulus G", measured at 200.degree. C. and at a frequency of 0.1 rad/s (0.1 s.sup.-1), with a value of at least 0.80.

Abstract: Compatibilized compositions comprising at least one polyamide and at least propylene polymer which is at least partially modified by a polar monomer, in which compositions the propylene polymer has a melt flow index (MFI) measured according to ASTM standard D 1238-86 (230/2.16 conditions) higher than 50 g/10 min.

Abstract: Baths for the chemical polishing of stainless steel surfaces containing, in aqueous solution, a mixture of hydrochloric acid, phosphoric acid, nitric acid and of sulphosal cylic acid and at least one abietic compound.

Abstract: Structures with multiple polymeric layers comprising a vinylidene fluoride polymer layer bonded to a polar polymer layer by the use of a polymeric adhesive comprising a vinyl acetate polymer. These structures are characterized in that the product of the weight content of vinyl acetate of the polymeric adhesive, expressed in percent, and its dynamic viscosity at 100.degree. C. and 1 s.sup.-1, expressed in kPa s, is greater than 1.4.times.10.sup.3. The structures with multiple polymeric layers can take the form of films, sheets, panels, tubes or hollow bodies which can be employed particularly in the field of protection against corrosion or ultraviolet rays.

Abstract: Process for the manufacture of vinylidene fluoride polymers by noncontinuous polymerization of vinylidene fluoride in an aqueous medium with the use of peroxydisulphates as initiators and in the absence of emulsifying agent, in which an alkyl acetate, employed as a chain-control agent, is introduced into the initial aqueous charge intended for the polymerization.Use of the resulting vinylidene fluoride polymers for the manufacture of paints and, more particularly, of paints intended for prelacquering metal sheets with improved gloss.

Abstract: Process for the removal from vinyl chloride of compounds of ester type by an operation of treatment comprising an alkaline washing and a treatment with a hydride.

Abstract: An amorphous powder of titanium oxide and of barium and/or strontium oxide is precipitated by the hydrolysis of titanium alcoholate in the presence of barium oxide, hydroxide or alcoholate or strontium oxide, hydroxide or alcoholate and an acid organic compound containing more than 6 carbon atoms, and the amorphous powder is heated while being treated with a stream of gas containing water vapour, ammonia or CO.sub.2, to crystallize the barium or strontium titanate and distill off the acid organic compound. The barium or strontium titanate crystals are less than one micron in size and have an irregular, angular morphology.

Abstract: 1-Chloro-1,1-difluoroethane is prepared by reacting hydrogen fluoride with vinylidene chloride, in a liquid medium containing preferably at least 40 mol % 1,1-dichloro-1-fluoroethane.

Abstract: The extruded sleeve is cooled at the end of the die by a circulation of a refrigerant fluid whose temperature To satisfies the relationship: ##EQU1## G being equal to: ##EQU2## Tm and V being the mean temperature of the resin at the exit of the die and its mean extrusion velocity,Tc is a temperature characteristic of the extruded resin,.rho., Cp and .lambda. are the density, the specific heat and the thermal conductivity of the resin,H is the height of the die gap in the refrigerated zone,L is the length of the refrigerated zone.

Abstract: Compositions based on vinylidene fluoride polymers which have a reduced smoke-generating capacity, comprising an effective amount of a molybdenum derivative, such as the molybdate of calcium, zinc or aluminium, as a smoke reducer.The compositions are very particularly suitable for the manufacture of shaped articles used in building and in aeronautics.

Abstract: Process for the neutralization of a layer of acidic water over a sediment comprising a humic substance, according to which blocks of a sodium compound are made to fall through the water layer and to enter the sediment at least partially.

Abstract: The compositions contain, as vinyl chloride polymers, copolymers of vinyl chloride and of alkyl acrylates in which the alkyl radicals, consisting of linear or branched chains, contain from 1 to 10 carbon atoms and have an initial Shore A hardness not exceeding 85. They are suitable for the production of very diverse flexible articles, especially in the medical field (pouches for blood and for physiological fluids), the motor vehicle field (various profiles and seals) and the building industry (sealing sheets).

Abstract: The vinyl chloride polymers forming part of the composition of the plastisols result from the polymerization of vinyl chloride in aqueous medium with the aid of sulphosuccinamate(s). After gelling at 120.degree.-140.degree. C., the plastisols based on such polymers have an excellent adhesiveness to metal. They are more particularly suitable for coating sheet metal processed by electrostatic spraying.

Abstract: Storage-stabilized compositions based on vinylidene fluoride polymers containing a metal molybdate and, as stabilizer, an effective quantity of alkali metal or alkaline-earth metal carbonate.The compositions are most particularly suitable for the manufacture of shaped objects employed in building and in aeronautics.

Abstract: The flexible thermoplastic structures comprise a vinylidene chloride copolymer layer bonded to a plasticized vinyl chloride polymer layer through the intermediacy of a mixture of polymeric adhesives consisting of 10 to 90 parts by weight of a copolymer of vinyl acetate and ethylene and of 90 to 10 parts by weight of a copolymer of vinyl chloride and vinyl acetate and whose shear elastic modulus G' at 121.degree. C. and 10.sup.-4 cycles/second is greater than 0.5 10.sup.3 Pa.The flexible thermoplastic structures with coextruded polymeric layers may be in the form of films, sheets, tetra-packs or flexible pouches capable of being employed in the packaging field.

Abstract: A sheet of artificial leather made of polyvinyl chloride the back of which is coated with a dry adhesive capable of being activated by heat. The dry adhesive consisting of the product of the reaction between a substantially linear hydroxypolyurethane derived from a polyester and a partially blocked aromatic triisocyanate in a proportion such that the dry adhesive has an isocyanate value of at least 100. The adhesive may additionally contain polychloroprene. The sheet of artificial leather can be used for thermocovering of rigid articles which are not previously coated with glue, especially dash boards and door panels for motor vehicles made of ABS resin.