Abstract: Containers, which are impervious to hydrocarbon vapors, in particular to fuel vapors, and comprise an outer shell of plastic material, which is coated with a polyamide layer at least on the surface in contact with the fuel.Said containers are used in the sector of the fuel industry, in particular in the automotive industry, as tanks for automobiles and motor vehicles.

Abstract: Containers, which are impervious to hydrocarbon vapors, in particular to fuel vapors, and comprise an outer shell of plastic material, which is coated with a polyamide layer at least on the surface in contact with the fuel.Said containers are used in the sector of the fuel industry, in particular in the automotive industry, as tanks for automobiles and motor vehicles.

Abstract: Block copolyetheramide suitable for injection molding, consisting of polyamide blocks and polyalkylene ether blocks and having a melting point ranging from 215.degree. to 223.degree. C., an apparent viscosity, at 230.degree. C., ranging from 50 to 150 Pa, a number average molecular weight ranging from 10,000 to 50,000 and a yellow degree, measured by means of an Elrepho.RTM. apparatus, lower than or equal to 20. They are prepared by polymerizing the polyamide monomers in the presence of hypophosphorous acid or meta-hypophosphorous acid and then by polycondensing the polyamide with polyalkylene ether having hydroxyl end groups.

Abstract: Molding compositions having high rates of crystallization and suitable for being molded at a temperature of the mold not higher than 100.degree. C. to produce molded articles having an optimal combination of mechanical, physical, thermal properties and of surface appearance, comprising: a linear saturated polyester (A); a salt of a mono- or poly-carboxylic acid (B); an ionomer copolymer containing side carboxylic groups at least partially salified (C), and a solid inert inorganic substance (D) having a particle size not higher than 5 micrometers. Said compositions may be reinforced by reinforcing materials, preferably by glass fibers.

Abstract: A linear block copolymer of regular structure, comprising polyamide and polyethylene glycol blocks. Two polyamide blocks (A) are bound through an intermediate polyethylene glycol block (B) according to a structural scheme (A-B-A). Fibers exhibiting a high moisture absorption strong mechanical properties and a high dyeability. Textile manufactured goods comprising said fibers. A process to obtain said block copolymer, through the preparation of a polyamide (A) and a polyethylene glycol (B), and condensation of polyamide (A) and polyethylene glycol (B) so as to obtain a (A-B-A) structure.

Abstract: The invention is concerned with a combination of molecular weight controllers to be used in the production of a stabilized polyamide having a low content of monomers and oligomers and a high dye-taking capability by polymerization of caprolactam. The combination comprises: (a) a primary monofunctional amine having its boiling point at 180.degree. C. above, and a basic dissociation constant K.sub.b .gtoreq.1.7.times.10.sup.-5 ; (b) a monofunctional organic acid having a K.sub.a >1.5.times.10.sup.-5 ; and (c) an aminoacid containing at least ten carbon atoms having the --NH.sub.2 group salified by a monofunctional organic or inorganic acid which has K.sub.a >1.0.times.10.sup.-2. With this combination, a polyamide is obtained which, following residence in the molten state, has a monomer content of 0.25% or less and a dimer content of 0.15% or less.

Abstract: A new composition is described comprising a synthetic, artificial or natu polymer and a flameproofing additive imparting self-extinguishing properties to the composition and to the articles, such as moulded, spun or woven articles, made therefrom, said additive being the product of the reaction of melamine with acidic compounds, such as organic acids or anhydrides and inorganic acids. The process for making said additive by said reaction, preferably in the presence of water, is also described. The said composition may be made by introducing said additive in any manufacturing stage, viz. to the monomers (if the polymer is a synthetic one), to the molten polymer, to polymer solutions such as viscose dope, to polymer chips during extrusion, or to finished products e.g. by applying a finish to fabrics.

Abstract: A flame resistant and self-extinguishing copolyester composition is made by opolycondensing a dicarboxylic aromatic acid or its diester, a saturated aliphatic diol, a tetrabrominated diol and a sulphonated aromatic compound, preferably in the presence of a phosphor derivative as a complexing and stabilizing agent. Preferably the acid is terephthalic acid and the saturated diol is ethylene or butylene glycol. The viscosity of the copolyester is from 0.3 to 0.6 dl/g and preferably not less than 0.4 or more preferably 0.45 dl/g and its bromine and sulphur contents are 0.1-12% and 0.05-1% by weight respectively, the phosphor, if any, not exceeding 1%. A marked synergic effect of the concurrent presence of bromine and sulphur is evidenced by combustion tests.

Abstract: There is described a family of copolyester compositions for producing heat nd flame resistant fibers, said compositions being prepared by polycondensating (A) an aromatic diacid, (B) a diol, (C) a tetrabrominated diol, (D) a derivative of a polyvalent metal, all said components being hereinbelow defined, the polycondensation process being carried out in several successive stages of copolycondensation of components (A), (B) and (C) until reaching a stable viscosity, then adding component (D), and stopping the reaction before the intrinsic viscosity of the composition decreases below a value proper for subsequent spinning.

Abstract: A thermostable flameproofing agent for copolyesters is prepared by reacting ne mol of a diester of an alkali dicarboxyaryl sulphonate with 1-2 mols of at least one tetrabrominated diol in the presence of a transesterification catalyst chosen in the group consisting of compounds of Zn, Co, Ca, Sn, Ti and Mn. Copolyester compositions adapted for the preparation of formed bodies are prepared by the polycondensation of a dicarboxylic arylic acid or its diesters and a saturated aliphatic diol with said flameproofing agent and up to 1% by weight of a derivative of phosphorus in the presence of a catalyst consisting of Sb.sub.2 O.sub.3 or GeO.sub.2. Said compositions preferably have an intrinsic viscosity not less than 0.40 dl/g before their transformation into formed bodies and not less than 0.35 dl/g after said transformation.

Abstract: Pyrrolidone is anionically polymerized in the presence of alkali pyrrolidonate as catalyst and of carbamates of metals of Groups I and II of the Mendelyeev Periodic System, or of ammonium carbamates, as activators.