Provided is a composition containing fine fibers for forming a coating film. The composition has excellent spreadability and provides a coating film with excellent uniformity by application to a skin.

A composition for forming a coating film comprising the following components (a) and (b): (a) a fiber at 0.5 mass % or more and 10 mass % or less based on the total composition for forming a coating film. The fiber has an average fiber diameter of 0.1 μm or more and 7 μm or less and an aspect ratio [(average fiber length)/(average fiber diameter)] of 8 or more and 300 or less; and (b) a volatile component at 15 mass % or more and 90 mass % or less based on the total composition for forming a coating film.

The [(average fiber diameter).sup.2/(fiber content)] (μm.sup.2/mass %) of the composition is 0.005 or more and 7 or less, and the total content of the component (a) and the component (b) is 97 mass % or less.

The present disclosure relates to the production of polyacrylonitrile-based polymers with high conversion by a process comprising reacting acrylonitrile with at least one comonomer in the presence of a radical initiator in a liquid medium, wherein the radical initiator is present in an amount of from about 0.6 wt % to about 1.8 wt %, relative to the amount of acrylonitrile, and wherein no chain transfer agent is present. The polyacrylonitrile-based polymers produced may be used for producing carbon fiber, typically carbon fiber used in manufacturing composite materials.

The invention relates to a novel synthesis process in order to produce meltable PAN copolymers with increased thermal stability. The PAN copolymers produced using the method according to the invention surprisingly exhibit improved thermal and mechanical properties compared to PAN copolymers produced using methods known from the prior art. The invention additionally relates to corresponding PAN copolymers and to molded bodies produced therefrom or to a method for producing such molded bodies, in particular melt-spun mono- or mufti-filaments.

The invention relates to a novel synthesis process in order to produce meltable PAN copolymers with increased thermal stability. The PAN copolymers produced using the method according to the invention surprisingly exhibit improved thermal and mechanical properties compared to PAN copolymers produced using methods known from the prior art. The invention additionally relates to corresponding PAN copolymers and to molded bodies produced therefrom or to a method for producing such molded bodies, in particular melt-spun mono- or mufti-filaments.

A method for manufacturing a precursor fiber bundle provides precursor fiber bundles used in manufacturing carbon fiber bundles allowing high productivity and having high tensile strength with less yarn bundle divides in the fiber bundles. The method for manufacturing a precursor fiber bundle includes spinning by extruding a spinning solution through a spinneret to produce a coagulated fiber bundle, and interlacing the coagulated fiber bundle by applying a fluid onto the coagulated fiber bundle. The interlacing includes applying the fluid (18) under a pressure in a range of 0.01 to 0.05 MPa onto the coagulated fiber bundle (14) with a moisture content in a range of 25 to 50% under a tension of 0.02 g/dtex or less.

A method for manufacturing a precursor fiber bundle provides precursor fiber bundles used in manufacturing carbon fiber bundles allowing high productivity and having high tensile strength with less yarn bundle divides in the fiber bundles. The method for manufacturing a precursor fiber bundle includes spinning by extruding a spinning solution through a spinneret to produce a coagulated fiber bundle, and interlacing the coagulated fiber bundle by applying a fluid onto the coagulated fiber bundle. The interlacing includes applying the fluid (18) under a pressure in a range of 0.01 to 0.05 MPa onto the coagulated fiber bundle (14) with a moisture content in a range of 25 to 50% under a tension of 0.02 g/dtex or less.

The present disclosure relates to a process for producing one or more carbon fiber precursor fibers, particularly by spinning a polymer solution, wherein the polymer has a polydispersity (PDI) of less than or equal to 2, in a coagulation bath with a jet stretch of about 5 to about 60. The one or more carbon fiber precursor fibers produced may be used for producing carbon fiber, typically carbon fiber used in manufacturing composite materials.

The present disclosure relates to a process for producing homogeneous solutions comprising dissolved polyacrylonitrile-based polymer, and a system suitable therefor. The homogeneous polymer solutions produced by the process described herein may be used for producing carbon fiber, typically carbon fiber used in manufacturing composite materials.

The present disclosure relates to a method that includes polymerizing a nitrile with an acrylate ester to form a copolymer, in a mixture that includes water and an alcohol (R.sub.2—OH), according to the following reaction ##STR00001##
where R.sub.1 includes at least one of a first aliphatic group or hydrogen, R.sub.2 comprises at least one of a second aliphatic group or hydrogen, 100≤m≤4000, and 1≤n≤4000. In some embodiments of the present disclosure, the mixture may be an emulsion.

An optimized process for the preparation of a spinning solution for the production of acrylic fiber precursors (PAN) of carbon fibers and an optimized process for the production of carbon fibers from said acrylic precursor (PAN), are described.