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 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: Fiber made of cellulose formate and fiber made of cellulose regenerated from cellulose formate. These fibers exhibit high tenacity and modulus properties, combined with improved values of elongation at break and of energy at break. Their elongation at break, in particular, is greater than 6%. Methods for producing these fibers. The fiber made of cellulose formate is obtained by spinning a liquid crystal solution of cellulose formate according to the so-called dry-jet-wet spinning method, the coagulation stage and the neutral washing stage which follow both being carried out in acetone. The fiber made of cellulose formate in a highly concentrated aqueous sodium hydroxide solution. The spinning and regeneration methods can be employed in line and continuously. Reinforcing assemblies based on such fibers. Articles reinforced by such fibers or assemblies, these reinforced articles being in particular tires.

Abstract: The present invention provides a fiber made of cellulose formate which exhibits high tenacity and modulus properties, combined with improved values of elongation at break and of energy at break. The elongation at break, in particular, is greater than 6%. The invention also provides a method of producing the fiber by spinning a liquid crystal solution of cellulose formate according to the so-called dry-jet-wet spinning method, the coagulation stage and the neutral washing stage which follow both being carried out in acetone.

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.