Abstract: The invention concerns a coagulating agent for liquid crystal solutions with a base of cellulose substances, characterised in that it contains at least one water soluble additive selected from the group consisting of ammonia, amines of salt of these compounds, the additive being such that the pH of the said coagulating agent is greater than 6. A preferable additive is a salt elected from the group consisting of ammonium formates, acetates and phosphates, mixed salts of these compounds, or mixtures of these constituents, in particular diammonium orthophosphates (NH4)2HPO4. The invention also concerns a method for spinning a liquid crystal solution with a base of cellulose substances, using a coagulating agent as per the invention, in particular the method called the “dry-jet-wet-spinning” as well as spun articles, fibers or films, obtained by these methods.

Abstract: The invention concerns a coagulating agent for liquid crystal solutions with a base of cellulose substances, characterised in that it contains at least one water soluble additive selected from the group consisting of ammonia, amines of salt of these compounds, the additive being such that the pH of the said coagulating agent is greater than 6. A preferable additive is a salt elected from the group consisting of ammnonium formates, acetates and phosphates, mixed salts of these compounds, or mixtures of these constituents, in particular diammonium orthophosphates (NH4)2HPO4. The invention also concerns a method for spinning a liquid crystal solution with a base of cellulose substances, using a coagulating agent as per the invention, in particular the method called the “dry-jet-wet-spinning” as well as spun articles, fibers or films, obtained by these methods.

Abstract: The invention concerns a coagulating agent for liquid crystal solutions with a base of cellulose substances, characterised in that it contains at least one water soluble additive selected from the group consisting of ammonia, amines of salt of these compounds, the additive being such that the pH of the said coagulating agent is greater than 6. A preferable additive is a salt elected from the group consisting of ammonium formates, acetates and phosphates, mixed salts of these compounds, or mixtures of these constituents, in particular diammonium orthophosphates (NH4)2 HPO4. The invention also concerns a method for spinning a liquid crystal solution with a base of cellulose substances, using a coagulating agent as per the invention, in particular the method called the “dry-jet-wet-spinning” as well as spun articles, fibers or films, obtained by these methods.

Abstract: The invention concerns a coagulating agent for liquid crystal solutions with a base of cellulose substances, characterized in that it contains at least one water soluble additive selected from the group consisting of ammonia, amines of salt of these compounds, the additive being such that the pH of the said coagulating agent is greater than 6. A preferable additive is a salt selected from the group consisting of ammonium formates, acetates and phosphates, mixed salts of these compounds, or mixtures of these constituents, in particular diammonium orthophosphates (NH4) 2 HPO4. The invention also concerns a method for spinning a liquid crystal solution with a base of cellulose substances, using a coagulating agent as per the invention, in particular the method called “dry-jet-wet-spinning” as well as spun articles, fibers or films, obtained by these methods.

Abstract: The invention concerns an aqueous coagulating agent for a liquid crystal solution with a base of cellulose substances, characterized by the following: it contains water and at least one additive; when it is contacted with said solution, the diffusion kinetics (diffusion front D) of the coagulating agent and that of the precipitation (precipitation front P) of the cellulose substances by the action of said agent, measured under the microscope for the so-called “coagulation test” for an additive proportion of 20 wt. %, comply with the following relationship: 0.55 is <Kp/Kd≦1, Kp and Kd being respectively the factors of diffusion and precipitation (respective “Fick” straight line gradients), expressed in &mgr;ms½.

Abstract: The present invention describes a composition containing cellulose formate and a solvent system. The composition is a solution at a temperature of at least equal to a value Tf, while the composition is an elastic, thermoreversible gel at a temperature appreciably less than Tf. The present invention further describes a process for preparing a regenerated cellulose article by the transformation of this composition. The composition is then formed into a fiber or a film by gelation. The resulting regenerated cellulose fibers have excellent resistance to fibrillation, in particular wherein the fiber may be a monofilament fiber. These fibers or films may be used in textile applications or in technical applications, for example to reinforce other articles, such as tires.

Abstract: A composition containing cellulose formate and a solvent system. At a temperature at least equal to a value T.sub.f the composition is a solution, and at a temperature appreciably less than T.sub.f the composition is an elastic, thermoreversible gel.A process for preparing a regenerated cellulose article by the transformation of this composition. Gel spinning in order to obtain a fibre or a film. A regenerated cellulose fibre having an excellent resistance to fibrillation in particular, wherein the said fibre may be a monofilament fibre.These fibres or these films may be used in textile applications or in technical applications, for example for reinforcing other articles, particularly tires.

Abstract: Liquid-crystal solutions comprising cellulose dissolved in a solvent agent. They contain more than 10% by weight of cellulose, and are optically anisotropic at rest and at room temperature. The solvent agent contains more than 85% by weight of at least one phosphoric acid, this phosphoric acid or all of these phosphoric acids having the following average formula :?n(P.sub.2 O.sub.5), p(H.sub.2 O)!,with 0.33<(n/p)<1.0.A method of obtaining such solutions. Production of fibers or films from these solutions. Assemblages of such fibers of films. Articles reinforced by such fibers or films or assemblages, said articles being in particular tire casings.

Abstract: A composition containing cellulose formate and a solvent system. At a temperature at least equal to a value T.sub.f the composition is a solution, and at a temperature appreciably less than T.sub.f the composition is an elastic, thermoreversible gel.A process for preparing a regenerated cellulose article by the transformation of this composition. Gel spinning in order to obtain a fiber or a film. A regenerated cellulose fiber having an excellent resistance to fibrillation in particular, wherein the said fiber may be a monofilament fiber.These fibers or these films may be used in textile applications or in technical applications, for example for reinforcing other articles, particularly tires.

Abstract: A composition having a base of cellulose formate capable of producing fibers or films, containing as solvent one or more compounds selected from the group consisting of alkylsulfoxides, lactams, acyclic amides and cyclic derivatives of urea. A process for obtaining these fibers and films. A regenerated cellulose fiber the degree of substitution of which by formate groups is less than 3%. This fiber can be used for textile applications or in order to reinforce tires.

Abstract: A composition having a base of cellulose formate capable of producing fibers or films, containing as solvent one or more compounds selected from the group consisting of alkylsulfoxides, lactams, acyclic amides and cyclic derivatives of urea.A process for obtaining these fibers and films. A regenerated cellulose fiber the degree of substitution of which by formate groups is less than 3%.This fiber can be used for textile applications or in order to reinforce tires.

Abstract: The present invention provides a composition having a base of cellulose formate capable of producing fibers or films, containing as a solvent one or more compounds selected from the group consisting of alkylsulfoxides, lactams, acyclic amides and cyclic derivatives of urea. The invention further provides a process for obtaining these fibers and films, and a regenerated cellulose fiber having a degree of substitution by formate groups of less than 3%. The fiber is useful for textile applications or in order to reinforce tires.

Abstract: A process for producing a fiber or film of regenerated cellulose from a composition having a base of cellulose formate is provided. The composition is characterized by the following: (1) the composition is a solution; (2) the concentration of cellulose formate in the composition is at least 8% by weight; (3) the degree of substitution of the cellulose by formate groups is greater than 20% and (4) the composition contains one or more compounds selected from among alkylsulfoxides, lactams, acrylic amides and cyclic derivatives of urea as a solvent. The process for producing the fiber or film involves (i) transforming the composition into a liquid extrudate having the form of a fiber or film at a temperature at which the solution is isotropic at rest; (ii) coagulating the liquid extrudate; (iii) regenerating the cellulose of the fiber or film obtained and (iv) washing and drying the regenerated cellulose fiber or film.