A method of producing a hollow fiber membrane is provided. The method includes: extruding from a molding nozzle a membrane-forming stock solution, the membrane-forming stock solution containing a vinylidene fluoride-based resin, polyethylene glycol, and a common solvent, and having a slope (B) of 1.15 or more and less than 3.00 where the slope (B) is calculated by I=A×q.sup.−B from a scattering intensity of a small-angle X-ray; and solidifying the extruded membrane-forming stock solution in a solution containing water as a main component.

The disclosed technology relates to hollow fiber membranes prepared from a dope solution containing a polymer of vinyl chloride, such as chlorinated polyvinyl chloride, and a thermoplastic polyurethane.

The invention provides an enhanced electrospun film made from polyvinylidene fluoride (PVDF) and at least one low-melting-point polymer in a ratio of 99.9:0.1-90:10 by weight, and the low-melting-point polymer having a melting point lower than the polyvinylidene fluoride and a softening point in the range of 110-140 C°. The enhanced electrospun film exhibits excellent mechanical properties, higher moisture permeability and hydrostatic pressure resistance. The invention further provides a method for manufacturing the enhanced PVDF electrospun film, and use of the enhanced PVDF electrospun film in preparing a waterproof and moisture permeable product.

The invention provides an enhanced electrospun film made from polyvinylidene fluoride (PVDF) and at least one low-melting-point polymer in a ratio of 99.9:0.1-90:10 by weight, and the low-melting-point polymer having a melting point lower than the polyvinylidene fluoride and a softening point in the range of 110-140 C°. The enhanced electrospun film exhibits excellent mechanical properties, higher moisture permeability and hydrostatic pressure resistance. The invention further provides a method for manufacturing the enhanced PVDF electrospun film, and use of the enhanced PVDF electrospun film in preparing a waterproof and moisture permeable product.

A fiber for artificial hair formed of a polyvinyl chloride-based resin composition. The fiber for artificial hair has a value X1 of a loss tangent tans at 70° C. of 0.06 or more and 0.12 or less, when dynamic viscoelasticity is measured under the following conditions, and has a peak in a temperature range of 90° C. or higher and 110° C. or lower. (Dynamic viscoelasticity measurement conditions)The measurement is performed by sandwiching a bundle of 40 fibers for artificial hair that are arranged at a heating rate of 4° C./min and a frequency of 1 Hz.

A fiber for artificial hair formed of a polyvinyl chloride-based resin composition. The fiber for artificial hair has a value X1 of a loss tangent tans at 70° C. of 0.06 or more and 0.12 or less, when dynamic viscoelasticity is measured under the following conditions, and has a peak in a temperature range of 90° C. or higher and 110° C. or lower. (Dynamic viscoelasticity measurement conditions)The measurement is performed by sandwiching a bundle of 40 fibers for artificial hair that are arranged at a heating rate of 4° C./min and a frequency of 1 Hz.

The present invention provides a fiber for artificial hair and a hair decorating product having superior combing property. A fiber for artificial hair includes vinyl chloride based resin, vinyl based copolymer, and vinyl chloride based acrylic graft copolymer.

A polyvinyl chloride-based fiber for artificial hair that has excellent low glossiness and grip performance when woven and can be stably spun. Configuring a fiber for artificial hair using a polyvinyl chloride-based resin composition, wherein the polyvinyl chloride-based resin includes, at predetermined blending amounts, a polyvinyl chloride-based resin (A) having a viscosity-average polymerization degree of 450-1,700 and a crosslinked vinyl chloride-based resin (B) in which the viscosity-average polymerization degree of a component that dissolves in tetrahydrofuran is 1,800-2,300, the difference between the viscosity-average polymerization degree of the polyvinyl chloride-based resin (A) and the viscosity-average polymerization degree of the THF-soluble component of the crosslinked vinyl chloride-based resin (B) is in a predetermined range, and the cross-sectional shape of the fiber for artificial hair has a first projection, a second projection, and a third projection and the lengths and widths thereof satisfy predetermined conditions.

A polyvinyl chloride-based fiber for artificial hair that has excellent low glossiness and grip performance when woven and can be stably spun. Configuring a fiber for artificial hair using a polyvinyl chloride-based resin composition, wherein the polyvinyl chloride-based resin includes, at predetermined blending amounts, a polyvinyl chloride-based resin (A) having a viscosity-average polymerization degree of 450-1,700 and a crosslinked vinyl chloride-based resin (B) in which the viscosity-average polymerization degree of a component that dissolves in tetrahydrofuran is 1,800-2,300, the difference between the viscosity-average polymerization degree of the polyvinyl chloride-based resin (A) and the viscosity-average polymerization degree of the THF-soluble component of the crosslinked vinyl chloride-based resin (B) is in a predetermined range, and the cross-sectional shape of the fiber for artificial hair has a first projection, a second projection, and a third projection and the lengths and widths thereof satisfy predetermined conditions.

A fiber for artificial hair, the fiber containing 50 parts by mass or more and 95 parts by mass or less of a vinyl chloride-based resin and 5 parts by mass or more and 50 parts by mass or less of a vinyl-based copolymer resin, in which the vinyl-based copolymer resin contains 60% by mass or more and less than 70% by mass of a styrene-based monomer unit and more than 30% by mass and 40% by mass or less of an acrylonitrile-based monomer unit on the basis of the entire vinyl-based copolymer resin.