Abstract: In the present invention, a water-based wetting dispersant having an acid value of 5 mg KOH/g or more and an amine value of 10 mg KOH/g or less is used to dilute and disperse black carbon and a hydrophobic fluorine resin in an organic solvent to manufacture a slurry for microporous layer formation. In this regard, the added amount of the water-based wetting dispersant is adjusted to 5 to 30 parts by weight on the basis of 100 parts by weight of black carbon. In the present invention, the slurry is applied to at least one surface of carbon fiber paper and dried to form a microporous layer in which two independent peaks appear as analyzed on a particle size graph, followed by compression and deposition thereof to fabricate a gas diffusion layer including the microporous layer in which two independent peaks appear as analyzed on a particle size graph.

Abstract: A method for producing a roll-type gas diffusion layer is disclosed. The method includes preparing a carbon paper from carbon fiber chops having a low modulus of 10 to 100 Gpa; impregnating the prepared carbon paper with a phenol resin, and then carbonizing the resin-impregnated carbon paper at 1,800 to 2,400° C.; forming a microporous polytetrafluoroethylene resin layer on one side of the carbonized carbon paper, to prepare a gas diffusion layer sheet; and winding the prepared gas diffusion layer sheet on a roll. Since the roll of gas diffusion layer is formed using the carbon fiber chops having a low modulus, the gas diffusion layer exhibits excellent and uniform spreading properties. Therefore, sealing between the gas diffusion layer and the fuel cell separation plate is reliably secured without using a separate binder.

Abstract: An intermediate material of a thermoplastic prepreg for a fuel cell separation plate comprises a hydrophobic thermoplastic resin film and a fiber base. The hydrophobic thermoplastic resin film has a degree of crystallization of 1 to 20%, a thickness of 3 to 50 ?m, and (iii) a content of an electroconductive material of 1 to 20 wt. %. The film is laminated on at least one surface of the fiber base. The thermoplastic prepreg for a fuel cell separation plate is manufactured by pressurizing the thermoplastic prepreg intermediate material at a temperature higher than the melting point of the hydrophobic thermoplastic resin film. A fuel cell separation membrane manufactured using the thermoplastic prepreg intermediate material and thermoplastic prepreg is thin and light-weight, and have a good durability.

Abstract: A filament web type precursor fabric for an activated carbon fiber fabric is produced by (i) spreading precursor filaments for preparing activated carbon fiber in a web state; and (ii) punching the precursor filaments for preparing activated carbon fiber spread in a web state to entangle the precursor filaments for preparing activated carbon fiber with each other. The filament web type precursor fabric has a structure in which the precursor filaments for preparing activated carbon fiber are spread in a web form and entangled with each other, and has a weight per unit area ranging from 50 to 500 g/m2. An activated carbon fiber fabric manufactured by activating the filament web type precursor fabric contains yarns with improved and uniform durability and crystallinity, and an shows improved performance of forming microfine pores having a diameter of 1 to 2 nm.

Abstract: Disclosed is a method for producing roll-type gas diffusion layer. The method includes steps of preparing a carbon paper by using carbon fiber chops having a low modulus of 10 to 100 Gpa; impregnating the prepared carbon paper with a phenol resin or the like, and then carbonizing the same at 1,800 to 2,400° C.; forming a microporous polytetrafluoroethylene resin layer on one of both sides of the carbonized carbon paper, thus to prepare a sheet-like gas diffusion layer; and then, winding the prepared sheet-like gas diffusion layer on a roll.

Abstract: A method for preparing a high quality thermoplastic prepreg, includes: laminating a thermoplastic resin film having a crystallization degree in a range of 1 to 20% on at least one surface of a matrix fiber; and heating the laminate to a higher temperature than a melting point of the film, then, pressing the same. The method uniformly impregnates a matrix fiber with a thermoplastic resin, has a short curing cycle in the formation, and involves no random modification in alignment of fibers in the matrix fiber due to a low crystallization degree of the impregnated thermoplastic resin, thereby increasing rigidity of a formed product and enabling reduction of thickness. Thus produced prepreg has a low weight variation per unit area.

Abstract: A 0° unidirectional yarn prepreg and a preparation method are disclosed. The 0° unidirectional yarn prepreg has high-strength filaments which are arranged in parallel to each other in an axial direction X of a winding roller around which unidirectional yarn prepregs are wound and a resin is impregnated. The method includes steps of: (i) weaving a fabric using a thermoplastic film tape as a warp and using high-strength filaments as wefts; and (ii) performing thermal compression on the woven fabric at a temperature in which the warp is melted. Also, a multiaxial prepreg composite material is prepared by simultaneously and continuously supplying the 0° unidirectional yarn prepreg A prepared as described above method and a 90° unidirectional yarn prepreg B prepared by a conventional warping method to a thermal compression roller, and performing thermal compression thereon.

Abstract: A laminate for forming a composite material is provided. The laminate has a structure in that unidirectional yarn sheets S in which yarns are arranged in parallel to each other in one direction without bending and thermoplastic resin films F are alternately stacked so that the film F is located between the unidirectional yarn sheets S. The yarn sheets S and the films F having a degree of crystallinity XC of 30% or less are integrally coupled by stitching yarn Y, and adjacent unidirectional yarn sheets S are obliquely stacked at an angle of ±1° to ±90° to a direction in which yarns included in the respective unidirectional yarn sheets S are arranged. The use of unidirectional yarn sheets S, instead of fabrics or multi-axial fabrics, achieves excellent smoothness. Composite material manufactured using the laminate has uniform physical properties such as strength.

Abstract: An intermediate material of a thermoplastic prepreg for a fuel cell separation plate comprises a hydrophobic thermoplastic resin film and a fiber base. The hydrophobic thermoplastic resin film has a degree of crystallization of 1 to 20%, a thickness of 3 to 50 ?m, and (iii) a content of an electroconductive material of 1 to 20 wt. %. The film is laminated on at least one surface of the fiber base. The thermoplastic prepreg for a fuel cell separation plate is manufactured by pressurizing the thermoplastic prepreg intermediate material at a temperature higher than the melting point of the hydrophobic thermoplastic resin film. A fuel cell separation membrane manufactured using the thermoplastic prepreg intermediate material and thermoplastic prepreg is thin and light-weight, and have a good durability.

Abstract: A filament web type precursor fabric for an activated carbon fiber fabric is produced by (i) spreading precursor filaments for preparing activated carbon fiber in a web state; and (ii) punching the precursor filaments for preparing activated carbon fiber spread in a web state to entangle the precursor filaments for preparing activated carbon fiber with each other. The filament web type precursor fabric has a structure in which the precursor filaments for preparing activated carbon fiber are spread in a web form and entangled with each other, and has a weight per unit area ranging from 50 to 500 g/m2. An activated carbon fiber fabric manufactured by activating the filament web type precursor fabric contains yarns with improved and uniform durability and crystallinity, and an shows improved performance of forming microfine pores having a diameter of 1 to 2 nm.

Abstract: A method for preparing a high quality thermoplastic prepreg, includes: laminating a thermoplastic resin film having a crystallization degree in a range of 1 to 20% on at least one surface of a matrix fiber; and heating the laminate to a higher temperature than a melting point of the film, then, pressing the same. The method uniformly impregnates a matrix fiber with a thermoplastic resin, has a short curing cycle in the formation, and involves no random modification in alignment of fibers in the matrix fiber due to a low crystallization degree of the impregnated thermoplastic resin, thereby increasing rigidity of a formed product and enabling reduction of thickness. Thus produced prepreg has a low weight variation per unit area.

Abstract: Disclosed is an activated carbon fiber, more specifically, a filament-type activated carbon fiber that is manufactured by activating a filament-type precursor fiber for the activated carbon fiber and has a strength of 0.01 to 1.0 g/denier so as to have improved durability.

Abstract: A polyacrylonitrile-based precursor fiber for a carbon fiber and a method of producing the polyacrylonitrile-based precursor fiber, wherein the polyacrylonitrile-based precursor fiber includes a conductive carbon material are provided. The conductive carbon material may include at least one selected from the group consisting of carbon black, carbon nanotubes, graphene, and graphene oxide and may be used in an amount of 0.03 to 3.0 wt % based on the total amount of the polyacrylonitrile-based precursor fiber.

Abstract: Disclosed is a method for manufacturing carbon fiber which comprises the use of un-reacted raw material monomers in solution to prepare the precursor fiber for making the carbon fiber, and a relatively short passage period through hydrogen, which reduce production costs and increase returns. The present invention further comprises the carbon fiber precursors made thereby.

Abstract: The method for preparing a carbon fiber of the present invention includes the steps of: preparing a polyacrylonitrile-based polymer solution; spinning the polyacrylonitrile-based polymer solution to prepare a precursor fiber for a carbon fiber, the precursor fiber having a water content of 20-50%; converting the precursor fiber for a carbon fiber into a preliminary flame-retarded fiber while stretching the precursor fiber for a carbon fiber at an elongation rate of ?10˜?0.1% or 0.1˜5% at 180˜220° C. in air; converting the preliminary flame-retarded fiber into a flame-retardant fiber while stretching the preliminary flame-retarded fiber at an elongation rate of ?5˜5% at 200˜300° C. in air; and heating the flame-retardant fiber under an inert atmosphere to carbonize the flame-retardant fiber.

Abstract: The method for preparing a carbon fiber of the present invention includes the steps of: preparing a polyacrylonitrile-based polymer solution; spinning the polyacrylonitrile-based polymer solution to prepare a precursor fiber for a carbon fiber, the precursor fiber having a water content of 20-50%; converting the precursor fiber for a carbon fiber into a preliminary flame-retarded fiber while stretching the precursor fiber for a carbon fiber at an elongation rate of ?10˜?0.1% or 0.1˜5% at 180˜220° C. in air; converting the preliminary flame-retarded fiber into a flame-retardant fiber while stretching the preliminary flame-retarded fiber at an elongation rate of ?5˜5% at 200˜300° C. in air; and heating the flame-retardant fiber under an inert atmosphere to carbonize the flame-retardant fiber.

Abstract: Disclosed is a method for manufacturing carbon fiber which comprises the use of un-reacted raw material monomers in solution to prepare the precursor fiber for making the carbon fiber, and a relatively short passage period through hydrogen, which reduce production costs and increase returns. The present invention further comprises the carbon fiber precursors made thereby.

Abstract: Disclosed are a thermoplastic fiber with excellent durability and a fabric comprising the same. More particularly, the thermoplastic fiber contains fluoropolymer particles with average particle diameter ranging from 0.01 to 5.0/?II in thermoplastic resin to form the fiber. The inventive thermoplastic fiber is prepared by adding the fluoropolymer particles to the thermoplastic resin while spinning the thermoplastic resin. The inventive thermoplastic fiber exhibits superior durability, that is, resistance to friction and/or modification and is preferably adopted as yarns for footwear, furniture, (mountain-climbing) backpacks, abrasives, sportswear and so on.

Abstract: The present invention relates to a high shrinkage side-by-side type composite filament, wherein two kinds of thermoplastic polymers are arranged side by side type and a boiling water shrinkage (Sr2) measured by the method (initial load=notified denier×1/10 g, static load=notified denier×20/10 g) of clause 5.10 of JIS L 1090 is 20 to 75% of a boiling water shrinkage (Sr1) measured by the method (initial load=notified denier×1/30 g, static load=notified denier×40/30 g) of clause 7.15 of JIS L 1013. The side-by-side type composite filament is made of two kinds of thermoplastic polymers having a number average molecular weight difference (ïMn) of 5,000 to 15,000 upon spinning and the composite filament is drawn and heat-treated so as to satisfy the following physical properties: Temperature area exhibiting 95% of maximum thermal stress (Tmax, 95%): 120 to 230° C. Range of maximum thermal stress per denier: 0.1 to 0.

Abstract: The present invention relates to a dope dyed sea-island type conjugate multifilament. In the dope dyed sea-island type conjugate multifilament, which comprises easy soluble polymer as a sea component and polyester as an island component, the island component contains a dope dyed component selected from the group consisting of carbon black, pigments and dyestuffs and the temperature range (T?-T?) showing more than 95% of the maximum thermal stress of yarns is from 120° C. to 210° C. The dope dyed sea-island type conjugate multifilament of the present invention has an excellent thermal shrinkage property and excellent wash fastness and light fastness, and the dyeing process thereof can be omitted after producing a woven or knitted fabric because a dope dyed component is contained in the island component (ultra fine yarn). The dope dyed sea-island type conjugate multifilament of the present invention is useful as yarns for warp knit fabrics used in production of women's apparel.