Fibers and methods of producing fibers comprising fluorinated polymers having comonomers of tetrafluoropropene are provided. Methods may include providing a solution having a fluorinated polymer dissolved in a solvent, wherein at least one monomer of the polymer comprises a tetrafluoropropene, exposing the solution to an electrostatic field between the solution and a collection electrode, and forming fibers from the solution fluorinated polymer. Fibers may include a fluorinated polymer, wherein at least one of the monomers of the fluorinated polymer comprises tetrafluoropropene.

Provided is a hydrophilic fluororesin sheet having significantly improved properties such as filtering performance which includes primary fibers and secondary fibers having a smaller fiber diameter than a fiber diameter of the primary fibers, the secondary fibers crosslinking in each of the primary fibers and/or crosslinking between different primary fibers in such a manner that no knots are formed at crosslinking points, the primary fibers and the secondary fibers including fluororesin fibers including polytetrafluoroethylene [PTFE], wherein a surface of the sheet to which hydrophilization treatment has been applied.

Disclosed is a nonwoven fabric formed from (i) a nonwoven fabric substrate and (ii) a fluorine-containing polymer adhering to the nonwoven fabric substrate, wherein the fluorine-containing polymer contains:

(a) repeating units formed from a fluorine-containing monomer which is alpha-chloro acrylate or alpha-chloro acrylamide containing a fluoroalkyl group, and
(b) repeating units formed from a halogenated olefin monomer, and
the fluorine-containing polymer is free from repeating units formed from a (meth)acrylate containing a linear or branched hydrocarbon group having at least 18 carbon atoms.

Disclosed is a nonwoven fabric formed from (i) a nonwoven fabric substrate and (ii) a fluorine-containing polymer adhering to the nonwoven fabric substrate, wherein the fluorine-containing polymer contains:

(a) repeating units formed from a fluorine-containing monomer which is alpha-chloro acrylate or alpha-chloro acrylamide containing a fluoroalkyl group, and
(b) repeating units formed from a halogenated olefin monomer, and
the fluorine-containing polymer is free from repeating units formed from a (meth)acrylate containing a linear or branched hydrocarbon group having at least 18 carbon atoms.

A method for making a device with a fibrous sheet includes a step of combining a fiber-forming resin with a carrier resin to form a resinous mixture. The fiber forming resin has a fluorinated backbone with a pendent CF.sub.2CF.sub.2X group where X is a SO.sub.3H or SO.sub.2F. The carrier resin is a soluble polyamide. The resinous mixture is extruded to form an extruded resinous mixture. The extruded resinous mixture has fiber strands of the fiber-forming resin within the carrier resin. The extruded resinous mixture is contacted with water to separate the fiber strands of the fiber-forming resin from the carrier resin. Fiber forming strands are optionally cross-linked with ammonia and then are hydrolyzed to form ionomers.

A method for making a device with a fibrous sheet includes a step of combining a fiber-forming resin with a carrier resin to form a resinous mixture. The fiber forming resin has a fluorinated backbone with a pendent CF.sub.2CF.sub.2X group where X is a SO.sub.3H or SO.sub.2F. The carrier resin is a soluble polyamide. The resinous mixture is extruded to form an extruded resinous mixture. The extruded resinous mixture has fiber strands of the fiber-forming resin within the carrier resin. The extruded resinous mixture is contacted with water to separate the fiber strands of the fiber-forming resin from the carrier resin. Fiber forming strands are optionally cross-linked with ammonia and then are hydrolyzed to form ionomers.

A method for making a device with a fibrous sheet includes a step of combining a fiber-forming resin with a carrier resin to form a resinous mixture. The fiber forming resin has a fluorinated backbone with a pendent CF.sub.2CF.sub.2X group where X is a SO.sub.3H or SO.sub.2F. The carrier resin is a soluble polyamide. The resinous mixture is extruded to form an extruded resinous mixture. The extruded resinous mixture has fiber strands of the fiber-forming resin within the carrier resin. The extruded resinous mixture is contacted with water to separate the fiber strands of the fiber-forming resin from the carrier resin. Fiber forming strands are optionally cross-linked with ammonia and then are hydrolyzed to form ionomers.

A method for making a device with a fibrous sheet includes a step of combining a fiber-forming resin with a carrier resin to form a resinous mixture. The fiber forming resin has a fluorinated backbone with a pendent CF.sub.2CF.sub.2X group where X is a SO.sub.3H or SO.sub.2F. The carrier resin is a soluble polyamide. The resinous mixture is extruded to form an extruded resinous mixture. The extruded resinous mixture has fiber strands of the fiber-forming resin within the carrier resin. The extruded resinous mixture is contacted with water to separate the fiber strands of the fiber-forming resin from the carrier resin. Fiber forming strands are optionally cross-linked with ammonia and then are hydrolyzed to form ionomers.

The present invention relates to an acrylic fiber for artificial hair containing an acrylic copolymer. The fiber cross-section of the acrylic fiber has one or more shapes selected from the group consisting of a C-shape, a figure-6-shape, and a broad bean-shape with a hollow portion. Two ends of the C-shape, the figure-6-shape, or the broad bean-shape are apart from each other or are in contact with each other. A circumcircle of the fiber cross section has a diameter of 70 m or more and 100 m or less, an inscribed circle of the fiber cross section has a diameter of 15 m or more and 50 m or less, the thickness of the fiber cross section is 13 m or more and 40 m or less, and the canal width between the ends of the fiber cross section is 0 m or more and 15 m or less.

The present invention relates to an acrylic fiber for artificial hair containing an acrylic copolymer. The fiber cross-section of the acrylic fiber has one or more shapes selected from the group consisting of a C-shape, a figure-6-shape, and a broad bean-shape with a hollow portion. Two ends of the C-shape, the figure-6-shape, or the broad bean-shape are apart from each other or are in contact with each other. A circumcircle of the fiber cross section has a diameter of 70 m or more and 100 m or less, an inscribed circle of the fiber cross section has a diameter of 15 m or more and 50 m or less, the thickness of the fiber cross section is 13 m or more and 40 m or less, and the canal width between the ends of the fiber cross section is 0 m or more and 15 m or less.