The present invention provides a carbon fiber, which has excellent tensile strength by having fewer internal defects while being a thick fiber having a single-fiber diameter of 6.0 μm or greater, and can provide the effects of reducing costs while increasing production amount to enhance the yieldability of the carbon fiber.

The present invention relates to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber with enhanced spinnability, and more specifically, to a method for manufacturing a wholly aromatic liquid-crystalline polyester fiber including: pelletizing a resin manufactured by adding 1.08 equivalents to 1.12 equivalents of acetic anhydride to raw material monomers including hydroxy benzoic acid, hydroxy naphthoic acid, biphenol, terephthalic acid, and isophthalic acid, followed by solid-phase polycondensation, and melt-spinning under oil conditions in which winding-up improving oil is diluted to 0.5% to 2% and silicone spinning oil for high temperature is diluted to 0.5% to 2%, respectively, with water as a solvent.

Provided are staple fibers for air laid capable of improving dispersibility, and a method for producing the same. The staple fibers for air laid are characterized by including stable fibers to which a fiber treatment agent containing a hydrophilic oil agent and a silicone-containing oil agent is adhered in an amount of 0.7 to 2 wt % of a weight of the staple fibers, wherein a weight ratio of the hydrophilic oil agent and the silicone-containing oil agent contained in the fiber treatment agent (a weight of the hydrophilic oil agent/a weight of the silicone-containing oil agent) is within a range of 60/40 to 90/10, and a moisture content is 2 to 13%.

An elastic fiber of the present invention having an elastic fiber treatment agent attached to the fiber surface, comprises: a hydrocarbon resin (A) having a structure in which a polymer including a structural unit whose monomer is at least one selected from aromatic olefins and aliphatic diolefins as the main structural unit is partially or fully hydrogenated; and a hydrocarbon oil (B). In this way, an elastic fiber and a fiber structure comprising the same are provided that are suitable for obtaining an elastic sheet that has excellent elastic fiber unraveling properties and adhesiveness to hot melt adhesives, and that exhibits good adhesiveness even when processed at a high draft, and for obtaining a sanitary product that is soft to the touch.

A plurality of colored filament bundles are initially extruded separately, cooled and each combined into a partial thread. The partial threads are then separately pre-swirled and stretched individually or as a partial composite thread formed from a plurality of partial threads. Crimping then occurs. After the crimping, the partial threads and the partial composite thread are combined into a composite thread and wound into a coil. In accordance with certain techniques, a melt spinning apparatus has a pre-swirling apparatus having a plurality of swirling nozzles, a post-swirling device having a plurality of post-swirling nozzles and a crimping device having a plurality of texturing nozzles, wherein the nozzles are designed such that an individual partial thread or a partial composite thread formed from a plurality of partial threads can optionally be processed.

Provided is an elastic fiber treatment agent, containing; a hydrocarbon resin (A); and a hydrocarbon oil (B). The hydrocarbon resin (A) contains a polymer having a structural unit, as a main structural unit, derived from at least one monomer selected from aromatic olefin and aliphatic diolefin, the polymer being partially hydrogenated or fully hydrogenated. It is preferred that the hydrocarbon resin (A) contains a polymer having a structural unit derived from aromatic olefin as a monomer, the polymer being partially hydrogenated or fully hydrogenated, and the aromatic olefin is at least one selected from indene and methylstyrene. Thus, the elastic fiber treatment agent of the present invention imparts excellent unraveling properties to elastic fibers and has excellent adhesiveness to hot melt adhesives, enables the production of stretchable sheets exhibiting good adhesiveness even when processed at a high draft ratio, and is suitable for obtaining soft feel sanitary products.

Staple fibers and filament yarns formed from cellulose esters, such as cellulose acetate, are described herein, along with methods of making the fibers and their use in nonwoven fabrics and articles. The filament yarns and fibers described herein may be coated with at least one finish and, in some cases, may be coated with two or more finishes selected to enhance the properties of the fibers. Staple fibers as described herein may be used to produce nonwoven webs that are strong, soft, absorbent, and biodegradable, and may be used in wet or dry nonwoven articles for a variety personal care, medical, industrial, and commercial applications.

Staple fibers and filament yarns formed from cellulose esters, such as cellulose acetate, are described herein, along with methods of making the fibers and their use in nonwoven fabrics and articles. The filament yarns and fibers described herein may be coated with at least one finish and, in some cases, may be coated with two or more finishes selected to enhance the properties of the fibers. Staple fibers as described herein may be used to produce nonwoven webs that are strong, soft, absorbent, and biodegradable, and may be used in wet or dry nonwoven articles for a variety personal care, medical, industrial, and commercial applications.

Provided is an elastic fiber treatment agent, containing; a hydrocarbon resin (A); and a hydrocarbon oil (B). The hydrocarbon resin (A) contains a polymer having a structural unit, as a main structural unit, derived from at least one monomer selected from aromatic olefin and aliphatic diolefin, the polymer being partially hydrogenated or fully hydrogenated. It is preferred that the hydrocarbon resin (A) contains a polymer having a structural unit derived from aromatic olefin as a monomer, the polymer being partially hydrogenated or fully hydrogenated, and the aromatic olefin is at least one selected from indene and methylstyrene. Thus, the elastic fiber treatment agent of the present invention imparts excellent unraveling properties to elastic fibers and has excellent adhesiveness to hot melt adhesives, enables the production of stretchable sheets exhibiting good adhesiveness even when processed at a high draft ratio, and is suitable for obtaining soft feel sanitary products.

The present invention addresses the problem of suitably improving a treatment agent for a carbon fiber precursor in terms of the heat resistance and the effect of suppressing fusion between fibers during the step of flame-resisting treatment. This treatment agent for a carbon fiber precursor is characterized by containing a lubricant, the lubricant comprising a specific sulfur-containing diester compound and a specific sulfur-containing monoester compound.