Abstract: The present invention relates to a process for obtaining PAI fibers by spinning PAI in solution and to the fibers thus obtained. They are obtained by dry or wet spinning into dimethylalkyleneurea followed by removal of the solvent and overdrawing at high temperature. The yarns and fibers obtained are produced from PAI based on tolylene or meta-phenylene diisocyanate, and on an aromatic acid anhydride and/or an aromatic dianhydride, and optionally on one or a number of diacid compounds. They exhibit an outstanding thermomechanical behavior and make it possible to gain access to very low linear densities.

Abstract: The present invention relates to an enzyme with amidase activity, particularly towards substrates of the oligomer type derived from PA 6.

Abstract: The present invention relates to a process for the enzymatic hydrolysis of polyamides 6.6 to give adipic acid monomers and hexamethylenediamine monomers. The present invention further relates to an enzyme with amidase activity particularly towards substrates of the oligomer type derived from PA 6.6 and/or PA 6, said enzyme being characterized in that it consists of a peptide sequence corresponding to SEQ ID NO: 1 in the attached sequence listing and/or at least one polypeptide homologous to this sequence. The invention further relates to the DNA coding for said enzyme and to the biological precursors thereof The invention further relates to the microorganisms capable of producing this enzyme and to the hydrolysis process in which this enzyme and/or these microorganisms are applied.

Abstract: The invention concerns polyester filaments and method for manufacturing same. More particularly it concerns a filament made of glycol ethylene polyterephtalate or polynaphtalate having high mechanical properties, and a method for stretching polyester filaments. It is obtained by a stretching process comprising two steps including a first step in which a low stretching ratio is applied, to cause minimal crystallization of the polymer and, a second step with a high stretching ratio. The global stretching ratio can reach values higher than 12. The filament has in particular an expanded elastic range that enables the improvement of its useful properties, for instance for manufacturing screen printing grids.

Abstract: The present invention relates to a process for obtaining PAI fibres by spinning PAI in solution and to the fibres thus obtained. They are obtained by dry or wet spinning into dimethylalkyleneurea followed by removal of the solvent and overdrawing at high temperature. The yarns and fibres obtained are produced from PAI based on tolylene or meta-phenylene diisocyanate, and on an aromatic acid anhydride and/or an aromatic dianhydride, and optionally on one or a number of diacid compounds. They exhibit an outstanding thermomechanical behavior and make it possible to gain access to very low linear densities.

Abstract: Directly shapeable clear solutions of polyamide imides and a method for preparing same are provided. The solutions are obtained by polycondensation in .gamma.-butyrolactone (.gamma.BL) in substantially stoichiometric proportions between toluylene diisocyanate and an aromatic acid anhydride, and by dilution in (.gamma.BL) to give a solution allowing them to be processed at a later stage. Yarns and fibers made from said solutions are also described.

Abstract: The present invention relates to a process for obtaining continuously polyethylene terephthalate modified by --SiO-- groups in a proportion of 30014 700 ppm of Si during the direct esterification reaction between terephthalic acid and ethylene glycol, followed by polycondensation in a known manner by introducing methoxyethyl silicate or propyl silicate at a time when the prepolymer has a weight-average molecular mass of between 9,000 and 16,000, a polydispersity index of between 1.5 and 2, and when it is at a temperature of between 260.degree. and 290.degree. C., and at a pressure of between 1.5 and 2.5 bars, the silicate/prepolymer reaction time being at least 5 minutes.The present invention also relates to pilling-free fibers originating from the modified polyethylene terephthalate and to a process for obtaining them.

Abstract: Monofilament twist for applications, such as, for example, use as a reinforcement in tires, for paper-machine junction felts, as a canopy support and for knitting, braiding or other textile operations, consisting of at least two monofilaments of synthetic material of a grist at least equal to 20 tex, assembled, twisted and thermoset and virtually free of untwisting stress. The synthetic material is preferably based on polyamide or polyester. Process for the production of twists.

Abstract: The present invention relates to a reactivable paper and to a process for obtaining it.The paper consists of fibres with a heat resistance .gtoreq.180.degree. C., bonded together by means of a fibrous binder composed of polyamide or aromatic polyester pulp and of a chemical binder consisting of a polyether-imide of an aromatic polyester or of a resin of polyimide type, with a particle size smaller than 100 .mu.m, a softening point of between 50.degree. and 200.degree. C., and a degree of crosslinking of between 0.025 and 0.25. The weight proportion of fibres in the finished paper is generally preferably between 45 and 85%, that of the fibrous binder between 5 and 20%, that of the chemical binder between 10 and 50%.The papers are obtained by a wet route and find wide applications as a function of the degree of conversion of the resin, for example as a dielectric.

Abstract: An improved output efficient polyamide-based preoriented yarn spun at a speed of at least 4000 m/min and obtained by introducing, before the spinning, of a quantity of 0.05 to 1% by weight of pyrogenic silica of particle size of between 5 and 15 nm into the molten polymer in the form of dispersion in a master mix of the same polyamide as that intended to be processed, the filaments after spinning being then cooled by means of a gas stream at room temperature and then sized and wound at a speed of between 4200 and 5800 m/min. The preoriented yarns thus prepared exhibit a delay in the orientation and are obtained with a gain in output efficiency of at least 10%, generally at least 15%.

Abstract: A yarn with the appearance of a spun yarn, made from polyamide-based filaments. The yarn has crimped bulked parts, and parts which are both tight and interlaced, has a cohesion factor lying between 90 and 140 knots/meter, a Young's modulus lying between 100 and 150 cN/tex, and a difference in orientation between the two populations of filaments, evaluated by measurement of the sonic modulus, lying between 25 and 50 cN/tex. The textile articles obtained from this yarn simultaneously have a soft feel, bulk and strength.

Abstract: Undrawn preoriented polyester yarns containing 0.03 to 0.01% of fumed silica with a particle size of between 5 and 15 nm, exhibit a delay in crystallization.

Abstract: The present invention relates to a process for obtaining continuously polyethylene terephthalate modified by --SiO-- groups in a proportion of 300-700 ppm of Si during the direct esterification reaction between terephthalic acid and ethylene glycol, followed by polycondensation in a known manner by introducing methoxyethyl silicate or propyl silicate at a time when the prepolymer has a weight-average molecular mass of between 9,000 and 16,000, a polydispersity index of between 1.5 and 2, and when it is at a temperature of between 260.degree. and 290.degree. C. and at a pressure of between 1.5 and 2.5 bars, the silicate/prepolymer reaction time being at least 5 minutes.The present invention also relates to pilling-free fibres originating from the modified polyethylene terephthalate and to a process for obtaining them.

Abstract: Process for improving the output efficiency during the spinning of a polyamide-based preoriented yarn at a speed of at least 4000 m/min by introduction, before the spinning, of a quantity of 0.05 to 1% by weight of pyrogenic silica of particle size of between 5 and 15 nm into the molten polymer in the form of dispersion in a master mix of the same polyamide as than intended to be processed, the filaments after spinning being then cooled by means of a gas stream at room temperature and then sized and wound at a speed of between 4200 and 5800 m/min.The preoriented yarns thus prepared exhibit a delay in the orientation and are obtained with a gain in output efficiency of at least 10%, generally at least 15%.

Abstract: Process for improving the production efficiency of the spinning of an undrawn, preoriented yarn based on polyethylene terephthalate (PET) by the introduction, before the spinning, of 0.03 to 0.1% by weight of fumed silica with a particle size of between 5 and 15 nm into the molten polymer in the form of dispersion in a masterbatch of the same polymer as that to be processed, then spinning the PET containing the silica in the finely dispersed state, the filaments being next cooled by means of a gas stream at temperature between 17.degree. to 22.degree. C. and then sized and wound at a velocity of between 3500 and 5000 m/min.The gain in production efficiency, evaluated in relation to the shrinkage of the filaments in dry air at 180.degree. C., is at least 7%, generally at least 10-15%.

Abstract: The present invention relates to heat-resistant threads, filaments and fibres based on polyamide-imide. They have a polydispersion index I.ltoreq.2.2, a breaking tenacity.gtoreq.45 cN/tex, a Young's modulus.gtoreq.3.8 GPa, an elongation.ltoreq.25% and a color defined by the luminance Y>25%, the degree of whiteness DW<30 and the yellow index YI>170. In addition they have a very good stability to light, quantified by the retention of the mechanical characteristics. They have wide application in working and protective garments.

Abstract: The present invention relates to a substrate based on nonwoven sheet for a flat article.The substrate 11, with good dimensional stability in all the conditions of production, of subsequent treatments and of use, comprising at least one nonwoven sheet 8 based on chemical textile material in the form of continuous fibres or filaments is characterized in that the said sheet comprises high-modulus reinforcing threads 3 arranged parallel to each other in its lengthwise direction.Glass threads are preferably employed as reinforcing threads. The reinforcing threads are combined with the nonwoven sheet by chemical bonding or heat-bonding and/or needling.Use of the support as a sealing membrane reinforcement, primary or secondary substrate for tuft carpeting, reinforcement for floor covering tiling, substrate for laying, substrate for flock, and the like.

Abstract: The present invention relates to a process for obtaining semiordered polyamides-imides.More particularly it consists in performing the polycondensation in two separate stages:1) reaction between a part of an aromatic diisocyanate and all of the trimellitic anhydride in the presence of dimethylalkyleneurea of pH.ltoreq.7 until the intermediate compound has dissolved,2) successive addition of one or more aromatic diacids and of the remainder of the diisocyanate in the dimethylalkyleneurea of pH.ltoreq.7 until the polyamide-imide obtained has dissolved completely.The semiordered polymers thus obtained have a Tg lower than the random polymers, and this makes them easier to convert.

Abstract: The present invention relates to spinnable and mouldable polyamide-imide solutions as well as the process for their preparation.They contain 4 to 35% of a polyamide-imide having a polydispersity index.ltoreq.2.1 in a solvent mixture containing 45-100% by weight of DMEU and 0-55% of an aprotic polar solvent. They are obtained by the reaction, in dimethylethyleneurea of pH.ltoreq.7 as polycondensation solvent, of a diisocyanate, an aromatic acid anhydride, optionally an alkali or alkaline earth dicarboxybenzene sulphonate and optionally another aromatic dicarboxylic acid, the polyamide-imide concentration therefore being from 4 to 35%, then by dilution in a polar solvent at a temperature of between 120.degree. and 200.degree. C.The solutions thus obtained are limpid at ambient temperature, capable of being stored and have an improved color.

Abstract: A flavored synthetic monofilament useful for fishing is prepared by incorporating a flavoring agent throughout the mass of the monofilament. The monofilament can be either a homopolyamide or copolyamide having a breaking strength of at least 50 kg/mm.sup.2 for diameters less than or equal to 70/100 mm, of at least 30 kg/mm.sup.2 for diameters greater than 70/100 mm and less than or equal to 200/100 mm, and of at least 20 kg/mm.sup.2 for diameters greater than 200/100 mm and less than or equal to 300/100 mm and having a capacity to shrink in boiling water of greater than 1%.