US20100297443A1 - Ultrafine composite fiber, ultrafine fiber, method for manufacturing same, and fiber structure - Google Patents

Ultrafine composite fiber, ultrafine fiber, method for manufacturing same, and fiber structure Download PDF

Info

Publication number
US20100297443A1
US20100297443A1 US12/745,389 US74538909A US2010297443A1 US 20100297443 A1 US20100297443 A1 US 20100297443A1 US 74538909 A US74538909 A US 74538909A US 2010297443 A1 US2010297443 A1 US 2010297443A1
Authority
US
United States
Prior art keywords
resin
composite
fiber
formed product
ultrafine
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/745,389
Other languages
English (en)
Inventor
Toshio Kamisasa
Nobuo Ogata
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daiwabo Holdings Co Ltd
Daiwabo Polytec Co Ltd
Original Assignee
Daiwabo Holdings Co Ltd
Daiwabo Polytec Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2007311425A external-priority patent/JP5004774B2/ja
Application filed by Daiwabo Holdings Co Ltd, Daiwabo Polytec Co Ltd filed Critical Daiwabo Holdings Co Ltd
Assigned to DAIWABO POLYTEC CO., LTD., DAIWABO HOLDINGS CO., LTD. reassignment DAIWABO POLYTEC CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: OGATA, NOBUO, KAMISASA, TOSHIO
Publication of US20100297443A1 publication Critical patent/US20100297443A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
    • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D1/00—Treatment of filament-forming or like material
    • D01D1/04—Melting filament-forming substances
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D10/00—Physical treatment of artificial filaments or the like during manufacture, i.e. during a continuous production process before the filaments have been collected
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D01D5/0007—Electro-spinning
    • D01D5/0015—Electro-spinning characterised by the initial state of the material
    • D01D5/0023—Electro-spinning characterised by the initial state of the material the material being a polymer melt
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
    • D01D5/00—Formation of filaments, threads, or the like
    • D01D5/28—Formation of filaments, threads, or the like while mixing different spinning solutions or melts during the spinning operation; Spinnerette packs therefor
    • D01D5/30—Conjugate filaments; Spinnerette packs therefor
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/70—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres
    • D04H1/72—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged
    • D04H1/728—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres characterised by the method of forming fleeces or layers, e.g. reorientation of fibres the fibres being randomly arranged by electro-spinning
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/005—Synthetic yarns or filaments
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/016—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the fineness
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
    • D04H3/14—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic yarns or filaments produced by welding
    • D04H3/147—Composite yarns or filaments
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2929—Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2929—Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]
    • Y10T428/2931—Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]

Definitions

  • the present invention relates to an ultrafine fiber formed using electrospinning, a method for manufacturing the same, and a fiber structure containing an ultrafine composite fiber obtained by the aforementioned method.
  • synthetic fibers such as polyethylene terephthalate (PET) fibers, nylon fibers, and polyolefin fibers have been manufactured by melt-spinning in general.
  • PET polyethylene terephthalate
  • nylon fibers nylon fibers
  • polyolefin fibers have been manufactured by melt-spinning in general.
  • melt-spinning it is difficult to obtain ultrafine fibers, and particularly it is difficult to obtain fibers having a diameter of not more than 8 ⁇ m (single fiber fineness: about 1 decitex) stably.
  • Patent Document 1 proposes electrospinning methods as methods for obtaining ultrafine fibers. Solid-melt-electrospinning is disclosed in Patent Document 1.
  • Patent Document 1 JP 2007-239114 A
  • Patent Document 2 JP 2007-197859 A
  • Patent Document 3 JP 2005-154927 A
  • the conventional electrospinning methods have problems as follows.
  • a polymer that cannot be electrified easily is not formed into fine fibers easily even if a voltage is applied thereto, and it is difficult to apply such a polymer to electrospinning.
  • a supply resin before spinning has to be dissolved or dispersed in a solvent, which could lead to a problem of components originating from the solvent remaining in an obtained fiber. If a solvent remains in an obtained fiber, components originating from the solvent bleed out therefrom later, which could cause various problems.
  • the present invention obtains an ultrafine composite synthetic fiber and an ultrafine synthetic fiber by electrospinning, and provides a method for manufacturing an ultrafine composite fiber, and a fiber structure containing an ultrafine composite fiber.
  • An ultrafine composite fiber of the present invention is obtained by heating and melting a product formed of a composite resin (hereinafter this product is referred to as “composite-resin-formed product”) in front of a supply-side electrode and/or in a space between the supply-side electrode and a collection-side electrode and extending the composite-resin-formed product by electrospinning,
  • the composite-resin-formed product is a solid-state composite-resin-formed product having two or more phases and including a resin that has a volume specific resistance of 10 15 ⁇ cm or less and that is exposed on 30% or more of a surface of the composite-resin-formed product, and
  • fiber components composing the ultrafine composite fiber are in a phase separation state.
  • An ultrafine fiber of the present invention is obtained by removing any of components composing the ultrafine composite fiber.
  • a method for manufacturing an ultrafine composite fiber according to the present invention includes the steps of
  • the composite-resin-formed product is a solid-state composite-resin-formed product having two or more phases and including a resin that has a volume specific resistance of 10 15 ⁇ cm or less and that is exposed on 30% or more of a surface of the composite-resin-formed product;
  • a fiber structure of the present invention is obtained by heating and melting a composite-resin-formed product in front of a supply-side electrode and/or in a space between the supply-side electrode and a collection-side electrode and extending the composite-resin-formed product by electrospinning,
  • the composite-resin-formed product is a solid-state composite-resin-formed product having two or more phases and including a resin that has a volume specific resistance of 10 15 ⁇ cm or less and that is exposed on 30% or more of a surface of the composite-resin-formed product, and
  • fiber components composing the ultrafine composite fiber are in a phase separation state.
  • FIG. 1 is a schematic explanatory view of an electrospinning device according to one example of the present invention.
  • FIG. 2 is a schematic explanatory view of an electrospinning device according to another example of the present invention.
  • FIG. 3 is a scanning electron photomicrograph (SEM, magnification: 20,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 3 of the present invention.
  • FIG. 4 is a schematic cross-sectional view of the fiber shown FIG. 3 .
  • FIG. 5 is a scanning electron photomicrograph (SEM, magnification: 10,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 5 of the present invention.
  • FIG. 6 is a schematic cross-sectional view of the fiber shown in FIG. 5 .
  • FIG. 7 is a scanning electron photomicrograph (SEM, magnification: 4,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 6 of the present invention.
  • FIG. 8 is a schematic cross-sectional view of the fiber shown in FIG. 7 .
  • FIG. 9 is a scanning electron photomicrograph (SEM, magnification: 10,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 10 of the present invention.
  • FIG. 10 is a schematic cross-sectional view of the fiber shown in FIG. 9 .
  • FIG. 11 is a schematic explanatory view of an electrospinning device according to another example of the present invention, to perform electrospinning with respect to a plurality of composite fibers as a raw material.
  • FIG. 12A shows an exemplary cross section of a composite fiber as a raw material, which is a composite-resin-formed product, used in Example 2 of the present invention.
  • FIG. 12B shows an exemplary cross section of an ultrafine composite fiber obtained in Example 2 of the present invention.
  • FIG. 13A shows an exemplary cross section of a composite fiber as a raw material, which is a composite-resin-formed product, used in Example 3 of the present invention.
  • FIG. 13B shows an exemplary cross section of an ultrafine composite fiber obtained in Example 3 of the present invention.
  • FIG. 14 is a scanning electron photomicrograph (SEM, magnification: 2,000 times) of an ultrafine fiber obtained in Example 2, Experiment No. 13 of the present invention, in a state before EVOH was removed.
  • FIG. 15 is a scanning electron photomicrograph (SEM, magnification: 2,000 times) of the ultrafine fiber obtained in Example 2, Experiment No. 13 of the present invention, in a state after EVOH was removed.
  • FIG. 16 is a scanning electron photomicrograph (SEM, magnification: 2,000 times) of an ultrafine fiber obtained in Example 2, Experiment No. 14 of the present invention, in a state after EVOH was removed.
  • FIG. 17 is a scanning electron photomicrograph (SEM, magnification: 1,000 times) of an ultrafine fiber obtained in Example 2, Experiment No. 15 of the present invention, in a state after EVOH was removed.
  • FIG. 18 is a scanning electron photomicrograph (SEM, magnification: 5,000 times) of an ultrafine fiber obtained in Example 3, Experiment No. 18 of the present invention, in a state before EVOH was removed.
  • FIG. 19 is a scanning electron photomicrograph (SEM, magnification: 5,000 times) of an ultrafine fiber obtained in Example 3, Experiment No. 18 of the present invention, in a state after EVOH was removed.
  • FIG. 20 is a scanning electron photomicrograph (SEM, magnification: 5,000 times) of an ultrafine fiber obtained in Example 3, Experiment No. 19 of the present invention, in a state after EVOH was removed.
  • FIG. 21 is a scanning electron photomicrograph (SEM, magnification: 5,000 times) of an ultrafine fiber obtained in Example 3, Experiment No. 20 of the present invention, in a state after EVOH was removed.
  • a composite-resin-formed product in a solid state having two or more phases is used as a raw material, one or more resins in the composite resin have a volume specific resistance of 10 15 ⁇ cm or less, and this resin component is exposed on 30% or more of a surface of the composite-resin-formed product.
  • This composite-resin-formed product is electrified when passed through a supply-side electrode in a space between electrodes, and is extended by electrospinning, whereby an ultrafine composite fiber and an ultrafine fiber, which were difficult to obtain by a conventional technique, can be obtained without use of an organic solvent.
  • an organic solvent is not mixed in a supply resin before spinning, and the resin alone can be subjected to spinning. Accordingly, the present invention has an advantage in that no solvent is contained in an obtained fiber.
  • the inventors of the present invention examined why specific resins cannot be extended or drawn efficiently in solid-melt-electrospinning. Consequently, they found that some of specific resins such as polypropylene (PP) have high volume specific resistances of 10 16 to 10 20 ⁇ cm, and such resins are not easily electrified even when a voltage is applied thereto, and it is difficult to form them into ultrafine fibers. Typical resins have volume specific resistance as shown below.
  • PP polypropylene
  • the inventors considered forming resin components having low volume specific resistance into a composite-resin-formed product without using a solvent.
  • Various complex methods for composite-resin-formed products are available, and exemplary types of fiber-like composite-resin-formed products include the splittable type, the side-by-side type, the sea-island type, the core-sheath type (this further is classified into various types depending on components selected for the core and the sheath) from the viewpoint of the cross-sectional shape.
  • the volume specific resistance is measured according to ASTM D-257.
  • a voltage is applied across the supply-side electrode and the collection-side electrode in a space between these electrodes.
  • the voltage preferably is 20 to 100 kV, and more preferably 30 to 50 kV.
  • the voltage is in the above-described range, the electrification of resins is easily achieved, whereas sparks or corona discharge hardly occur between electrodes, which does not lead to a problem such as inflammation. If the voltage is less than 20 kV, electrodes have resistance therebetween in a space in the atmosphere (in the space between the electrodes), which could impair flow of electrons, thereby causing resins to be not easily electrified. If the voltage exceeds 100 kV, sparks or corona discharge could occur between electrodes, which could cause burning of the resins.
  • a distance between the electrodes may be determined, in view of a fiber diameter of an obtained ultrafine composite fiber, fiber diameter variation, and a property of accumulation of an ultrafine fiber on the collection-side electrode.
  • the distance between the electrodes preferably is 2 to 25 cm, and more preferably 5 to 20 cm. In the case where the distance is in the above-described range, the electrification of a resin is caused easily, sparks or corona discharge hardly occur between the electrodes, and therefore there is no problem of burning or the like. If the distance between the electrodes is less than 2 cm, sparks or corona discharge tend to occur, possibly burning a resin. If the distance exceeds 25 cm, a resistance between the electrodes increases, interfering with the flow of electrons, so that a resin tends to be not easily electrified.
  • a composite-resin-formed product supplied to the supply-side electrode preferably is supplied in a solid state.
  • the composite-resin-formed product may be heated to be in a molten or semi-molten (soften) state.
  • the product preferably is supplied in a fiber state.
  • a shape of a cross section of the ultrafine composite fiber tends to be analogous to a shape of a cross section of the fiber-state composite-resin-formed product.
  • this makes it possible to control easily a cross-sectional shape of an ultrafine composite fiber obtained by electrospinning.
  • the composite-resin-formed product preferably is a monofilament, a multifilament composed of a plurality of monofilaments bundled, or a tow.
  • the “multifilament” refers to that composed of 2 to 100 filaments
  • the “tow” refers to that composed of more than 100 filaments.
  • the composite-resin-formed product preferably is a multifilament or a tow composed of 2 to 1,000 monofilaments bundled.
  • a composite-resin-formed product (e.g., a solid composite fiber) is irradiated with a laser beam immediately after the beam passes the supply-side electrode, whereby the composite-resin-formed product is heated and melted. Even in the case where the composite-resin-formed product is molten or semi-molten preliminarily, the composite-resin-formed product is made to have a low viscosity by additional heating and melting in the space between the electrodes, whereby extensibility can be improved.
  • the laser beam include a laser beam emitted from light sources such as a YAG laser, a carbon dioxide gas (CO 2 ) laser, an argon laser, an excimer laser, and a helium-cadmium laser.
  • the laser beam emitted from a carbon dioxide gas laser is preferred, from the viewpoint of a high heat absorptivity with respect to a polymer resin, a high power source efficiency, and a high composite fiber melting property.
  • the laser beam has a wavelength of, for example, 200 nm to 20 ⁇ m, preferably 500 nm to 18 ⁇ m, more preferably 1 to 16 ⁇ m (particularly 5 to 15 ⁇ m) approximately.
  • a known means such as a means of near infrared radiation in a wavelength range of 780 nm to 2.5 ⁇ m may be used.
  • a beam diameter of the laser beam irradiating a composite fiber can be selected according to the shape of the composite fiber.
  • a specific beam diameter may be, in the case of a linear-form resin for example (e.g., monofilament, multifilament, tow, etc), greater than an average diameter of the linear-form resin, and is in a range of, for example, 0.5 to 30 mm, preferably 1 to 20 mm, more preferably 2 to 15 mm (particularly 3 to 10 mm).
  • the beam diameter may be such that a ratio of the beam diameter to the average diameter of the linear-form resin is 1:1 to 100:1, preferably 1:2 to 1:50, and more preferably 1:3 to 1:30 (particularly 1:5 to 1:20).
  • a distance between an end on a side of the supply-side electrode from which the composite-resin-formed product comes out and a portion of the product irradiated with the laser beam is 1 to 6 mm preferably. More preferably the distance is 2 to 4 mm. If the distance is less than 1 mm, the laser-irradiated portion is very close to the electrode, thereby causing the temperature of the electrode to rise. As a result, the resin-formed product is heated longer in time, which could cause the resin to be decomposed.
  • the amount of electric charges in the resin-formed product electrified when the product passes through the supply-side electrode decreases, and even if such a portion of the product is heated and molten by the laser beam, the resin in the molten state is not easily extended uneasily toward the collection-side electrode.
  • An output power of the laser beam necessary for melting the composite-resin-formed product may be controlled so that the product can be heated to a temperature that is not lower than a melting point of a resin having the highest melting point among resins composing the composite-resin-formed product, and at which none of the resins composing the composite-resin-formed product is ignited or decomposed.
  • the composite-resin-formed product may assume a viscous state.
  • the temperature at which the composite-resin-formed product assumes a viscous state varies with the rate of supply of the composite-resin-formed product, the output power of the laser beam, the distance between the laser and the composite-resin-formed product, and the fineness of the composite-resin-formed product.
  • the heating temperature preferably is 160° C. to 1200° C., and more preferably 600° C. to 800° C. If the temperature is lower than 160° C., the amount of heat for heating the product is insufficient, whereby melting failures occur. This causes the product to fail to assume a viscous state, making it difficult to form the product into an ultrafine fiber. If the temperature is over 1,200° C., the resin might be burned or decomposed, which makes it impossible to form the resin into fibers.
  • the specific output power of the laser beam may be selected appropriately depending on the physical property (melting point), shape, fineness, and supply rate of the composite-resin-formed product used.
  • the output power thereof may be, for example, 3 to 100 mA, preferably 3 to 50 mA, and more preferably 6 to 40 mA If the output power of the laser beam is less than 3 mA, the power is not enough to melt the resin.
  • Irradiation conditions of the laser beam may be controlled by the melting point of the composite-resin-formed product. In the case where, however, the composite-resin-formed product is a filament having a small diameter and a high voltage is applied thereto, the control of the conditions is performed by the control of the output power of the laser beam from the viewpoint of conveniences. One or a plurality of points around the composite-resin-formed product is irradiated with the laser beam.
  • the composite-resin-formed product molten is extended toward the collection-side electrode in accordance with the electric attraction force.
  • the extension ratio is 100 to 1000 times, preferably 200 to 800 times, and more preferably 300 to 500 times.
  • the product is extended at such a ratio, thereby being formed into ultrafine fibers.
  • hyperextension possibly could occur.
  • the diameter of the ultrafine composite fiber containing a resin having a volume specific resistance exceeding 10 15 ⁇ cm can be decreased to 5 ⁇ m or less. Under preferable conditions, the diameter can be decreased to 3 ⁇ m or less, and under more preferable conditions, the diameter can be decreased to 1 ⁇ m or less.
  • the composite-resin-formed product preferably is of a sea-island type, a splittable type, or a core-sheath type as viewed in a cross section thereof.
  • a resin that easily is electrified upon passing through the supply-side electrode can be arranged selectively.
  • the fiber diameter is derived from a diameter of the fiber when the fiber has a round cross section.
  • the fiber diameter (diameter) is determined from a fiber cross section or a fiber side face.
  • the fiber has a cross section in an irregular shape (polygonal, elliptic, hollow, “C”-shaped, “Y”-shaped, “X”-shaped, or indefinite-shaped cross section, etc.)
  • a circular shape having the same area as that of the cross section of the fiber is given and the diameter of the round shape is determined, which is assumed to be the diameter of the fiber. Therefore, in the case of an oddly-shaped fiber, the fiber diameter cannot be derived from the side face of the fiber.
  • the resin exposed on 30% or more of the surface of the part of the composite-resin-formed product that is passed through the supply-side electrode preferably has a volume specific resistance of 10 6 to 10 14 ⁇ cm. More preferably, the resistivity is 10 7 to 10 14 ⁇ cm. With this configuration, the composite-resin-formed fiber is electrified easily when it is passed through the supply-side electrode.
  • a resin having a volume specific resistance of more than 10 15 ⁇ cm could possibly be made suitable for electrospinning, by decreasing an apparent volume specific resistance using one of the following techniques alone or a plurality of the same in combination by the time when it is electrospun: processing techniques for decreasing a resistivity of a resin, such as kneading a master batch that causes a volume specific resistance of a resin to decrease (e.g., a master batch containing a filler such as carbon or a metal salt), corona processing, fluorine processing, and electret processing; and processing techniques of coating the composite-resin-formed product with an oil agent that allows a volume specific resistance to decrease (e.g., an anionic surfactant, a cationic surfactant, or a nonionic surfactant) or immersing the composite-resin-formed product with such an oil agent.
  • processing techniques for decreasing a resistivity of a resin such as kneading a master batch that causes a volume specific
  • the “apparent volume specific resistance” refers to a value obtained by determining a volume specific resistance (ASTM D-257) of a sample obtained by subjecting a resin portion of the sample to the aforementioned processing technique, the volume specific resistance (ASTM D-257) being determined usually with respect to a resin.
  • the volume specific resistance is not a volume specific resistance of a resin itself, but a value indicative of a volume specific resin of a processed resin.
  • a configuration in which a resin having a volume specific resistance of 10 15 ⁇ cm or less is exposed on 30% or more of a surface of a composite-resin-formed product has the following advantage: even if a resin having a volume specific resistance of more than 10 15 ⁇ cm and therefore becoming electrified uneasily is included in the configuration, the resin having a volume specific resistance of 10 15 ⁇ cm or less is sufficiently electrified and electrospun, and the influences of the same cause even the resin having a volume specific resistance of more than 10 15 ⁇ cm to be electrospun and extended at the same time.
  • a proportion of a resin having a volume specific resistance of 10 15 ⁇ cm or less is 10 percent by mass (mass %) or more, preferably 30 mass % or more, and more preferably 50 mass % or more in a composite-resin-formed product.
  • an uneasily electrified resin having a volume specific resistance of 10 16 ⁇ cm or more such as olefin (e.g., polypropylene, or polyethylene)
  • excellent electrospinning can be performed if there is 10 mass % or more of a resin having a volume specific resistance of 10 15 ⁇ cm or less.
  • a resin having a volume specific resistance of 10 16 ⁇ cm or more, such as olefin, and a resin having a volume specific resistance of 10 15 ⁇ cm or less are used, a preferable proportion of the resin having a volume specific resistance of 10 15 ⁇ cm or less is 10 mass % to 70 mass %.
  • the proportion is 35 mass % to 60 mass %. If the resin having a volume specific resistance of 10 15 ⁇ cm or less accounts for less than 10 mass %, the ultrafineness is not easily achieved, and if the resin accounts for more than 70 mass %, there is no problem in electrospinning, but it is difficult to stably obtain a composite-resin-formed product as a raw material, since an olefin portion is extremely small when the composite-resin-formed product is produced.
  • the component exposed on 30% or more of the surface of the composite-resin-formed product is at least one selected from ethylene-vinyl alcohol copolymers, polyesters, nylons, and polyurethanes, and that a component of the other phase is at least one selected from polyolefins, polyesters, nylons, and polylactic acids.
  • the component exposed on 30% or more of the surface of the composite-resin-formed product particularly preferably is an ethylene-vinyl alcohol copolymer, from the viewpoint that an ethylene-vinyl alcohol copolymer can be highly electrified and has a great extensibility upon electrospinning and has excellent biocompatibility.
  • the ethylene-vinyl alcohol copolymer has a volume specific resistance of, preferably, 10 6 to 10 5 ⁇ cm, more preferably 10 7 to 10 9 ⁇ cm, and further more preferably 10 75 to 10 8.5 ⁇ cm.
  • the ethylene-vinyl alcohol copolymer is obtained by saponification of an ethylene-vinyl acetate copolymer.
  • the content of ethylene in the ethylene-vinyl alcohol copolymer is not limited particularly, but preferably is 25 to 70 percent by mole (mol %), and more preferably 30 to 65 mol %.
  • Commercially available examples of the same include “EVAL” (trade name) produced by Kuraray Co., Ltd., “Soarnol” (trade name) produced by Nippon Synthetic Chemical Industry Co., Ltd., and such commercially available products can be used in the present invention.
  • the melting point of an ethylene-vinyl alcohol copolymer varies with the content of ethylene and vinyl alcohol contained therein, and for example, an ethylene-vinyl alcohol copolymer containing 38% of ethylene has a melting point of 171° C., and an ethylene-vinyl alcohol copolymer containing 55% of ethylene has a melting point of 142° C.
  • the ethylene-vinyl alcohol copolymer used may be an ethylene-vinyl alcohol copolymer of a single type, or alternatively, a mixture of two or more types of ethylene-vinyl alcohol copolymers that are different in the content of ethylene.
  • the ethylene-vinyl alcohol copolymer preferably has a melting point of 100° C. to 190° C., more preferably 120° C. to 180° C., and further preferably 140° C. to 175° C.
  • the melting point of ethylene-vinyl alcohol copolymer is 100° C. or higher, the composite-resin-formed product is easily formed into fibers, and when the melting point of ethylene-vinyl alcohol copolymer is 190° C. or lower, the thermal bonding of intersection points of fibers can be performed at a relatively low temperature.
  • the component of the other phase is not limited particularly, and, for example, one of the following, or a mixture of two or more of the following, may be used as the component: polyolefins such as polyethylene, polypropylene, polybutene, polymethylpentene, polytrimethylene terephthalate, ethylene-propylene copolymer; polyesters such as polyethylene terephthalate, and polybutylene terephthalate; polyamides such as nylon 6, and nylon 66; and polystyrene.
  • the component of the other phase preferably has a melting point in a range of 150° C. to 300° C., from the viewpoint of obtaining a fiber strength.
  • examples of a polymer having a melting point in a range of 150° C. to 300° C. include polypropylene (160° C. to 175° C.), polymethyl pentene (230° C. to 240° C.), polyethylene terephthalate (212° C. to 265° C.), polybutylene terephthalate (220° C. to 267° C.), nylon 6 (210° C. to 220° C.), and nylon 66 (255° C. to 265° C.) (“Plastic Data Book”, edited by Asahi Kasei Amidas Corporation, Plastics Editorial Section, published on Dec. 1, 1999 by Kogyo Chosakai Publishing Inc., pages 7 to 11).
  • a composite fiber such as a core-sheath-type composite fiber, a sea-island-type composite fiber, or a splittable-type composite fiber in which a component that is exposed on 30% or more of a surface is an ethylene-vinyl alcohol copolymer and a composite of the other phase is a polylactic acid can be used in the following materials to be embedded in a living body, since both components are highly biocompatible and such a composite fiber does not contain a solvent in the fiber.
  • the exemplary materials in which the foregoing composite fiber can be used include materials to be embedded in a living body such as surgical sutures, stents, and artificial joints; medical materials such as hematostatic materials, cell culture substrates, masks, and body fluid absorbing pads; and cosmetics such as face masks, and interpersonal wipes.
  • the ultrafine composite fibers preferably do not contain solvents in the fiber itself. More preferably, the resin composing the ultrafine composite fiber does not contain an organic solvent or a component originating from an organic solvent. In the case where the ultrafine composite fiber does not contain a solvent in the fiber itself, it can be applied to a field of products brought into contact with humans and a medical field, since a solvent or a component originating from such a solvent, which are generally toxic with respect to humans and animals, never is eluted from such a fiber. It should be noted that the “component originating from an organic solvent” refers to a component such as a solvent chemically changed by heat or electric charges.
  • the composite-resin-formed product in a solid state may contain no solvent.
  • the composite-resin-formed product not containing a solvent is obtained by, for example, spinning a resin by a conventional melt-spinning method, in the case where the composite-resin-formed product is in a fiber form.
  • the “solvent” refers to that which can dissolve or disperse a resin therein and exhibits toxicity with respect to humans and animals.
  • the solvent include hexane, benzene, toluene, diethyl ether, chloroform, ethyl acetate, tetrahydrofuran, methylene chloride, acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, acetic acid, 1-butanol, 1-propanol, 2-propanol, methanol, ethanol, and formic acid.
  • the ultrafine composite fiber preferably does not contain a solvent in the fiber itself.
  • the ultrafine composite fiber preferably has a diameter of 20 ⁇ m or less, more preferably a diameter in a range of 0.2 to 17 ⁇ m, and particularly preferably a diameter in a range of 0.5 to 5 ⁇ m.
  • the ultrafine fiber having a diameter in such a range is difficult to obtain by a normal melt-spinning technique.
  • a composite fiber obtained by electrospinning preferably has phase separation of two components, that is, one component that is exposed on 30% of or more a surface of the fiber, and another component having the other phase.
  • the phase separation causes the components to easily separate from each other, whereby an ultrafine fiber can be obtained easily.
  • the ultrafine composite fiber preferably is of a sea-island type, a splittable type, or a core-sheath type as viewed in its cross-section.
  • an ultrafine fiber obtained has such a cross-sectional shape that the multifilament or the two becomes one fiber in some cases.
  • An exemplary case is as follows: in the case where a tow composed of 600 core-sheath-type composite fibers bundled is used as a composite-resin-formed product, an ultrafine composite fiber obtained by extension through electrospinning is of a sea-island type in which the number of segments of an island component is 1 to 600 apparently.
  • An ultrafine fiber having such a cross-sectional shape is also included in examples of the sea-island type and/or core-sheath type composite fiber in the present invention.
  • the composite fiber preferably contains 30 to 90% of the component exposed on 30% or more of the surface, and 70 to 10% of the component of the other phase. More preferably, the ratio of the former fiber to the latter fiber is 35:65 to 60:40. When the ratio is in the foregoing range, the product is easily electrified in the space between the electrodes, whereby excellent spinning properties are achieved.
  • the segment unit of each individual resin component is small (as viewed in a cross-section, the structure is a group of very small units). Therefore, it is considered that the structure is influenced easily by the electrification of the resins at the supply-side electrode, and by the heating and melting of the resins by a laser beam, and therefore, which allows the entire segments to be homogeneously influenced.
  • a finer fiber may be taken out from the obtained ultrafine composite fiber by further removing either one of the resin components.
  • the removing method is not limited particularly, and a known method using an acid, an alkali, an organic solvent, or the like may be used.
  • the removing method may be selected appropriately, according to a solubility product of a resin with respect to a solvent.
  • a core-sheath-type composite fiber in which the sheath and the core are formed with an ethylene-vinyl alcohol copolymer and a polylactic acid respectively, water at 80° C. to 100° C., or an alkaline aqueous solution obtained by dissolving potassium hydroxide, sodium hydroxide, or sodium hydrogencarbonate in water may be used, in order to remove the polylactic acid.
  • DMSO dimethyl sulfoxide
  • isopropyl alcohol heated to 60° C., 2-propanol or the like may be used.
  • the extended ultrafine composite fiber is allowed to have various shapes depending on the method for heating the composite-resin-formed product as a raw material. For example, homogeneous heating allows a fiber having a cross-section in a shape analogous to that of the composite-resin-formed product to be obtained. Heating the composite-resin-formed product from one side causes bias in a molten state as viewed in the cross-section, thereby allowing a fiber having an unsymmetrical cross-section shape to be obtained.
  • one resin side face is molten sufficiently thereby being extended, while an opposite side face has a greater melting viscosity as compared with the other side and is not extended sufficiently, which results in that an ultrafine composite fiber obtained has a shape different from that of the composite-resin-formed product.
  • the circular cross-section of the composite-resin-formed product is turned into a C-letter-shaped cross-section of the obtained ultrafine composite fiber, or the core component is split into two or more, whereby a further finer fiber could be obtained.
  • the ultrafine composite fibers are accumulated on the collection-side electrode, whereby a fiber structure can be obtained.
  • the fiber structure in its accumulated state may be collected directly from the collection electrode.
  • the collection-side electrode may be formed in a conveyer form, and the position at which fibers are accumulated may be shifted continuously so that a sheet-form fiber structure can be produced continuously.
  • another method of collecting a fiber structure is as follows: a metal mesh, a woven fabric, a nonwoven fabric, or a sheet of paper is arranged on the collection-side electrode, and ultrafine composite fibers are accumulated on such a sheet-form material, whereby a laminate-like fiber structure can be obtained.
  • fibers may be accumulated in a non-sheet shape, such as an article having a certain thickness such as a cartridge-type filter.
  • the “fiber structure” refers to a fiber accumulation such as an article having a certain thickness, for example, a fiber sheet, a filter, and the like.
  • a physical object to be accumulated preferably is grounded so as to have no potential difference from the collection-side electrode. If no problem arises in the production, however, they do not have to be grounded intentionally, and may be held slightly afloat on the collection-side electrode.
  • a combination of EVOH and PP also is a preferable example.
  • the ethylene-vinyl alcohol copolymer (EVOH) may be removed further, so that a polypropylene (PP) fiber alone can be obtained.
  • the removal of ethylene-vinyl alcohol copolymer (EVOH) is achieved by, for example, immersing the obtained fiber in an aqueous solution containing 2-propanol, or dimethyl sulfoxide (DMSO).
  • DMSO dimethyl sulfoxide
  • the polypropylene ultrafine fiber preferably has a fiber diameter of 13 ⁇ m or less, and more preferably, 5 ⁇ m or less.
  • an ultrafine composite fiber formed to have a diameter of about 1.2 ⁇ m and a core-sheath ratio of 50:50 under preferable conditions may be subjected to removal of ethylene-vinyl alcohol copolymer, whereby a further finer polypropylene ultrafine fiber having a diameter of 0.3 ⁇ m can be obtained.
  • the extended ultrafine composite fiber and/or polypropylene as a core component is allowed to have various shapes depending on the method for heating the composite-resin-formed product as a raw material.
  • homogeneous heating allows a fiber having a cross-section in a shape analogous to that of the composite-resin-formed product to be obtained.
  • Heating the composite-resin-formed product from one side causes bias in a molten state as viewed in the cross-section, thereby allowing a fiber having an unanalogous cross-section shape to be obtained.
  • one resin side face is sufficiently melted thereby being extended, while an opposite side face has a greater melting viscosity as compared with the other side, which results in that an ultrafine composite fiber has a shape different from that of the composite-resin-formed product.
  • the circular cross-section of the composite-resin-formed product is turned into a C-letter-shaped cross-section of the obtained ultrafine composite fiber, or the core component is split into two or more, whereby a further finer fiber could be obtained.
  • FIG. 1 specifically illustrates an electrospinning device according to an example of the present invention.
  • a voltage generator 3 applies a voltage across the supply-side electrode 1 and the collection-side electrode 2
  • a laser irradiation equipment 4 emits a laser beam in a direction indicated by an arrow X toward a position immediately under the supply-side electrode 1 .
  • a distance between the supply-side electrode and the collection-side electrode preferably is 2 to 25 cm. The distance is more preferably 5 to 20 cm. If the distance between the electrodes is smaller than 2 cm, sparks or corona discharge occur due to the application of a high voltage.
  • a composite fiber 7 as a raw material is taken out of housed fibers 6 contained in a container 5 , passes via guides 8 and 9 , and a supply roller 10 , and thereafter is supplied to the electrospinning device 11 .
  • the composite fiber as a raw material may be supplied from a bobbin around which the material is wound.
  • the composite fiber 7 is electrified when passing the supply-side electrode.
  • the composite fiber 7 in this electrified state, is irradiated with the laser beam emitted from the laser irradiation equipment 4 in the arrow X direction, so as to be heated and melted, immediately under the supply-side electrode 1 , and is extended toward the collection-side electrode by the electric attraction force.
  • the composite fiber is extended in a direction indicated by an arrow Y, becoming ultrafine.
  • “ 12 ” denotes a fiber structure (sheet) obtained from accumulation of the composite fibers that have been made ultrafine.
  • a position immediately under the supply-side electrode 1 may be irradiated by the laser irradiation equipment 4 via a reflection plate mirror 13 .
  • the laser beam is swung by an angle ⁇ between a direction indicated by an arrow X 1 and a direction indicated by an arrow X 2 .
  • This allows all of the composite fibers 7 a to 7 f as raw materials to be irradiated with a laser beam. This makes spinning possible even if a plurality of composite fibers or a nonwoven fabric is used as the composite-resin-formed product.
  • FIG. 2 schematically illustrates another electrospinning device according to another example of the present invention.
  • This electrospinning device 20 applies a voltage from a high-voltage terminal 22 to a supply-side electrode 21 attached to a polyimide resin plate 23 .
  • the supply-side electrode preferably is in a needle shape.
  • the needle length preferably is 5 to 30 mm, and more preferably 10 to 20 mm. If the needle length is less than 5 mm, the direction in which the composite fiber as a raw material is to be extruded is not set, which makes it difficult to guide the composite fiber to the laser beam irradiation position.
  • the needle preferably has an inner diameter of 10 to 2000 ⁇ m, and more preferably 20 to 1650 ⁇ m. If the inner diameter is less than 20 ⁇ m, the number of fibers to be processed decreases, and also it is difficult to pass the raw material fibers therethrough since it is narrow. If the inner diameter exceeds 2000 ⁇ m, there could be a difficulty in electrifying the fibers sufficiently, particularly inward parts thereof.
  • the needle electrode does not have to be one in number.
  • a bundle of a plurality of thin needles, rather than one thick needle is advantageous regarding the guiding property for guiding raw material fibers toward the laser beam irradiation position.
  • the number of needles preferably is 1 to 1,000, and more preferably 1 to 300.
  • the collection-side electrode 24 is earthed. A position immediately under the supply-side electrode 21 is irradiated with laser beams in directions indicated by arrows X 1 and X 2 from a plurality of laser irradiation equipment 25 . Composite fibers 7 as a raw material are electrified when passing the supply-side electrode 21 .
  • the composite fibers 7 in this electrified state are irradiated, at a position immediately under the supply-side electrode 21 , with laser beams emitted by the laser irradiation equipment 25 in the directions indicated by arrows X 1 and X 2 , the composite fibers 7 are heated and molten, and extended toward the collection-side electrode 24 by an electric attraction force.
  • the composite fibers 7 are extended several hundred times in length, for example, in a direction indicated by the arrow Y, thereby being made ultrafine.
  • “ 29 ” denotes an accumulation of composite fibers that have been made ultrafine.
  • the heating-extending region 28 preferably is heated by transmitting heat from a heating means such as a heater or an oil tank, so that the fibers are not cooled rapidly.
  • the temperature of the heating-extending region depends on the type of the fiber, but the region may be heated to a temperature in a range from a glass-transition point to a melting point of a synthetic fiber.
  • the temperature in the heating-extending region preferably is 50 to 300° C., and more preferably 100 to 200° C.
  • the heating preferably is performed by a method using electricity, since minute temperature adjustment is performed easily by such a method
  • FIG. 12A is a cross-sectional view of a composite fiber as a composite-resin-formed product as a raw material used in one example of the present invention.
  • This composite fiber 70 is a monofilament that has a core-sheath structure having a core 71 made of polypropylene (PP) and a sheath 72 made of an ethylene-vinyl alcohol polymer (EVOH).
  • FIG. 12B is a cross-sectional view of an ultrafine composite fiber obtained in one example of the present invention.
  • This composite fiber 73 has a core-sheath structure having a polypropylene (PP)-made core 74 that is made ultrafine, and an ethylene-vinyl alcohol copolymer (EVOH)-made sheath 75 that is made ultrafine.
  • PP polypropylene
  • EVOH ethylene-vinyl alcohol copolymer
  • FIG. 13A is a cross-sectional view of a composite fiber that is a composite-resin-formed product as a raw material used in another example of the present invention.
  • a composite fiber 76 is a multifilament obtained by temporarily fixing a plurality of core-sheath-type filaments into a bundle, each filament having a core 77 made of polypropylene (PP) and a sheath 78 made of an ethylene-vinyl alcohol copolymer (EVOH).
  • the filaments can be fixed temporarily to be bundled, for example, by pouring boiled water over a plurality of composite fibers.
  • FIG. 13B is a cross-sectional view of an ultrafine composite fiber obtained in another example of the present invention.
  • the composite fiber 80 has a core-sheath structure having polypropylene (PP)-made cores 81 that are made ultrafine and ethylene-vinyl alcohol copolymer (EVOH)-made sheaths 82 that are made ultrafine.
  • PET Polyethylene terephthalate
  • T200E trade name
  • IV intrinsic viscosity
  • Nylon 6 (NO: “1015B” (trade name) produced by Ube Industries, Ltd., having a molecular weight of 15000
  • High-density polyethylene “HE481” (grade name) produced by Japan Polyethylene Corporation, having a melting point of 130° C., and a melt flow rate of 12 determined according to JIS-K-7210 (MFR; temperature upon determination: 190° C., load: 21.18 N (2.16 kgf))
  • Polylactic acid (PLA) used in Experiments Nos. 11 and 12 “U'z S-32” produced by Toyota Motor Corp., having a melting point of 179° C. and a volume specific resistance of 9 ⁇ 10 16 ( ⁇ cm).
  • a raw-material composite-resin-formed product was obtained as follows: an unextended fiber was obtained by conventional melt-spinning, and was used as a composite-resin-formed product (composite fiber) as a raw material.
  • the device shown in FIG. 2 was used under the conditions as shown in Table 2.
  • Laser device PIN-30R manufactured by Onizca Glass Co., Ltd. (rated output: 30 W, wavelength: 10.6 ⁇ m, beam diameter: 6 mm)
  • Supply-side electrode UN series, 20Gx 15 (as one unit), manufactured by Unicontrols Co., Ltd.
  • a first component, a second component, a cross-sectional structure, a resin ratio, and a fiber diameter of a raw-material composite-resin-formed product of each of Experiments Nos. 1 to 12 are as shown in Table 2.
  • Ultrafine fibers were produced by the electrospinning method shown in FIG. 2 , with use of these raw-material composite-resin-formed products.
  • the electrospinning conditions and the fiber diameters of the obtained ultrafine fibers are shown collectively in Table 2.
  • the sheath component of the composite fiber was polyolefin, and therefore, the resin having a volume specific resistance of 10 15 ⁇ cm or more and not easily electrified was present on 100% of the surface of the composite fiber. As a result, it was impossible to perform spinning.
  • FIG. 3 A scanning electron photomicrograph (SEM, magnification: 20,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 3 is shown in FIG. 3 , and a specific cross-sectional view of the fiber is shown in FIG. 4 .
  • “ 30 ” denotes an ultrafine composite fiber of a core-sheath structure
  • “ 31 ” denotes Ny
  • “ 32 ” denotes PET. Since it was a core-sheath type composite fiber in which PET having a volume specific resistance of 10 15 ⁇ cm or less was the sheath component and hence was exposed on 100% of a surface of the fiber, excellent spinning properties were obtained, and the extended fiber was in a phase separation state. In the present case under these conditions, since the composite-resin-formed product having a core-sheath structure was used as a raw material, an ultrafine composite fiber having an analogous shape was obtained.
  • FIG. 5 A scanning electron photomicrograph (SEM, magnification: 10,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 5 was shown in FIG. 5 , and a schematic cross-sectional view of the fiber is shown in FIG. 6 .
  • “ 40 ” denotes an ultrafine composite fiber having a 16-part-split structure
  • “ 41 ” denotes PET
  • “ 42 ” denotes PE. Since the fiber was a splittable-type composite fiber in which Ny having a volume specific resistance of 10 15 ⁇ cm or less was used and the resin having a low volume specific resistance was exposed on 50% of the surface, excellent spinning properties were exhibited, and the extended fiber was in a phase separation state. In the present case, since the splittable-type composite-resin-formed product was used as a raw material, a splittable-type ultrafine composite fiber having an analogous shape was obtained.
  • FIG. 7 A scanning electron photomicrograph (SEM, magnification: 4,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 6 of the present invention was shown in FIG. 7 , and a cross-sectional view of the fiber is shown in FIG. 8 .
  • “ 50 ” denotes an ultrafine composite fiber having a 16-part-split structure
  • “ 51 ” denotes PET
  • “ 52 ” denotes PE. Since the fiber was a splittable-type composite fiber in which Ny having a volume specific resistance of 10 15 ⁇ cm or less was used and the resin having a low volume specific resistance was exposed on 50% of the surface, excellent spinning properties were exhibited, and the extended fiber was in a phase separation state.
  • FIG. 10 A scanning electron photomicrograph (SEM, magnification: 10,000 times) of a cross section of an ultrafine fiber obtained in Experiment No. 10 was shown in FIG. 9 , and a schematic cross-sectional view of the fiber is shown in FIG. 10 .
  • “ 60 ” denotes an ultrafine composite fiber having a sea-island structure
  • “ 61 ” denotes PP
  • “ 62 ” denotes EVOH.
  • a sea-island-type composite-resin-formed product was used as a raw material, a sea-island-type ultrafine composite fiber having an analogous shape was obtained.
  • the ultrafine fiber obtained in Experiment No. 11 was substantially identical to those of FIGS. 5 and 6 .
  • “ 40 ” denotes an ultrafine composite fiber having a 16-part-split structure
  • “ 41 ” denotes PLA
  • “ 42 ” denotes EVOH. Since the fiber was a splittable-type composite fiber in which EVOH having a volume specific resistance of 10 15 ⁇ cm or less was used and the resin having a low volume specific resistance was exposed on 50% of the surface, excellent spinning properties were exhibited, and the extended fiber was in a phase separation state.
  • the ultrafine fiber obtained in Experiment No. 12 had a cross section substantially identical to those of FIGS. 3 and 4 .
  • “ 30 ” denotes an ultrafine composite fiber having a core-sheath structure
  • “ 31 ” denotes PLA
  • “ 32 ” denotes EVOH. Since the fiber was a core-sheath-type composite fiber in which the sheath component was EVOH having a volume specific resistance of 10 15 ⁇ cm or less and was exposed on 100% of the surface, excellent spinning properties were exhibited, and the extended fiber was in a phase separation state.
  • Ultrafine fibers were produced by the above-described electrospinning method, with the use of these raw-material fibers.
  • a scanning electron photomicrograph (SEM, magnification: 2,000 times) of an ultrafine fiber obtained in Experiment No. 13 is shown in FIG. 14 .
  • the fibers obtained in Experiments Nos. 14 and 15 also had similar appearances.
  • the ultrafine fibers obtained were immersed sufficiently in a mixed solution at 90° C. composed of 70 g of 2-propanol and 30 g of distilled water until ethylene-vinyl alcohol copolymer (EVOH) was dissolved completely therein, so that the ethylene-vinyl alcohol copolymer (EVOH) was removed from the fibers.
  • the scanning electron photomicrographs (SEM, magnification: 2,000 times) of the ultrafine fibers of Experiments Nos. 1 to 3 after EVOH was removed are shown in FIGS. 15 to 17 .
  • the obtained results are shown in Table 3.
  • fibers having a cross-sectional structure shown in FIG. 13A were used as raw-material fibers that are composite-resin-formed products. Core and sheath components, resin ratios, and fiber diameters in these experiments are shown in Table 4. 60 of these fibers were bundled. The bundling was performed by fixing ends on one side of these 60 fibers with use of a dip, aligning the fibers by slightly pulling the other ends so as to make them tense, temporarily fixing them by pouring boiled water, and drying the same. For example, in Experiment No. 18, 60 filament fibers having a fiber diameter of 120 ⁇ m were bundled, as shown in FIG. 13A
  • ultrafine fibers were produced by the above-described electrospinning method.
  • a scanning electron photomicrograph (SEM, magnification: 5,000 times) of an ultrafine fiber obtained in Experiment No. 18 is shown in FIG. 18 .
  • the fibers obtained in Experiments Nos. 19 and 20 also had similar appearances.
  • the ultrafine fibers obtained were immersed sufficiently in a mixed solution at 90° C. composed of 70 g of 2-propanol and 30 g of distilled water until ethylene-vinyl alcohol copolymer (EVOH) was dissolved completely therein, so that the ethylene-vinyl alcohol copolymer (EVOH) was removed from the fibers.
  • the scanning electron photomicrographs (SEM, magnification: 5,000 times) of the ultrafine fibers of Experiments Nos. 18 to 20 after EVOH was removed are shown in FIGS. 19 to 21 .
  • the obtained results are shown in Table 4.
  • polypropylene (PP) fibers obtained after removal of ethylene-vinyl alcohol copolymer (EVOH) had fiber diameters of 0.43 to 1.28 ⁇ m.
  • Ultrafine composite fibers and fiber structures obtained in the present invention are useful in filters, battery separators (separators for lithium ion batteries in particular), paper, nonwoven fabrics, skin layers for synthetic leather substitute, and the like. Further, such fibers also are useful in materials to be embedded in a living body such as surgical sutures, stents, and artificial joints; medical materials such as hematostatic materials, cell culture substrates, masks, and bodily fluid absorbing pads; and cosmetics such as face masks, and interpersonal wipes.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Multicomponent Fibers (AREA)
  • Nonwoven Fabrics (AREA)
  • Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
  • Artificial Filaments (AREA)
US12/745,389 2007-11-30 2009-11-28 Ultrafine composite fiber, ultrafine fiber, method for manufacturing same, and fiber structure Abandoned US20100297443A1 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2007-311535 2007-11-30
JP2007-311425 2007-11-30
JP2007311425A JP5004774B2 (ja) 2007-11-30 2007-11-30 極細複合繊維及びその製造方法、並びに繊維構造物
JP2007311535 2007-11-30
PCT/JP2008/071677 WO2009069759A1 (fr) 2007-11-30 2008-11-28 Fibre composite ultrafine, fibre ultrafine, son procédé de fabrication et structure de fibre

Publications (1)

Publication Number Publication Date
US20100297443A1 true US20100297443A1 (en) 2010-11-25

Family

ID=40678648

Family Applications (1)

Application Number Title Priority Date Filing Date
US12/745,389 Abandoned US20100297443A1 (en) 2007-11-30 2009-11-28 Ultrafine composite fiber, ultrafine fiber, method for manufacturing same, and fiber structure

Country Status (4)

Country Link
US (1) US20100297443A1 (fr)
EP (1) EP2221402A4 (fr)
CN (1) CN101878331B (fr)
WO (1) WO2009069759A1 (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110003144A1 (en) * 2006-11-14 2011-01-06 Philip John Brown Capillary-channeled polymer fibers modified for defense against chemical and biological contaminants
US20110177395A1 (en) * 2008-09-04 2011-07-21 Daiwabo Holdings Co., Ltd. Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof
JP2012112067A (ja) * 2010-11-24 2012-06-14 Univ Of Fukui 繊維マットの製造方法、及び、繊維マット
US20130017748A1 (en) * 2011-07-15 2013-01-17 Samsung Electro-Mechanics Co., Ltd. Porous sheet and method for manufacturing the same
US20130085212A1 (en) * 2010-05-04 2013-04-04 Consejo Superior De Investigaciones Cientificas (Csic) Procedure for the obtainment of nanocomposite materials
WO2013157969A1 (fr) 2012-04-17 2013-10-24 Politechnika Łodzka Matériel médical pour reconstruction de vaisseaux sanguins, son procédé de fabrication et utilisation du matériel médical pour la reconstruction de vaisseaux sanguins
US20140357144A1 (en) * 2011-12-19 2014-12-04 Virginia Tech Intellectual Properties, Inc. Melt Electrospun Fibers Containing Micro and Nanolayers and Method of Manufacturing
US9142815B2 (en) 2010-06-21 2015-09-22 Kolon Industries, Inc. Method for manufacturing a porous nanoweb
US20150287967A1 (en) * 2012-10-23 2015-10-08 Cornell University Ceramic nanofiber separators
JP2016089317A (ja) * 2014-11-11 2016-05-23 日本ポリプロ株式会社 溶融紡糸型エレクトロスピニング用プロピレン系樹脂組成物、およびそれを用いたプロピレン系極細繊維の製造方法、並びにその方法により製造されたプロピレン系極細繊維
JP2016125182A (ja) * 2015-01-08 2016-07-11 パナソニックＩｐマネジメント株式会社 不織布およびそれを用いた空気清浄機、ならびに不織布の製造方法
EP3444387A4 (fr) * 2016-04-11 2019-11-13 Kao Corporation Procédé de production de fibre ultrafine

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101845676B (zh) * 2010-05-18 2012-05-23 北京航空航天大学 一种复合纤维及其制备方法
WO2011149836A1 (fr) 2010-05-24 2011-12-01 Drexel University Échafaudages anisotropes électrofilés à matrice textile pour l'ingénierie tissulaire et la médecine régénérative
CN103320876B (zh) * 2013-06-24 2015-09-23 江南大学 一种静电纺丝线型喷头
CN104088022B (zh) * 2014-07-02 2016-06-01 北京化工大学 一种制备多级超细纤维的组合静电纺丝装置及方法
WO2016199082A1 (fr) * 2015-06-12 2016-12-15 Reliance Industries Limited Dispositif d'entremêlement électrostatique et procédé d'entremêlement de filaments
WO2017148460A2 (fr) 2016-03-01 2017-09-08 Bisping Medizintechnik Gmbh Dispositif et procédé pour filage électrostatique commandé par structure
CN108884595B (zh) * 2016-04-11 2022-04-08 花王株式会社 极细纤维的制造方法
JP2019007113A (ja) * 2017-06-28 2019-01-17 Ｊｘｔｇエネルギー株式会社 極細繊維の製造装置及び極細繊維の製造方法
JP6810663B2 (ja) * 2017-06-28 2021-01-06 Ｅｎｅｏｓ株式会社 極細繊維の製造装置
CN112481825B (zh) * 2020-11-24 2021-11-09 苏州康嘉医疗用品有限公司 一种熔喷布加工系统

Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5814404A (en) * 1994-06-03 1998-09-29 Minnesota Mining And Manufacturing Company Degradable multilayer melt blown microfibers
US20020100725A1 (en) * 2001-01-26 2002-08-01 Lee Wha Seop Method for preparing thin fiber-structured polymer web
US6552123B1 (en) * 1998-12-16 2003-04-22 Kuraray Co., Ltd. Thermoplastic polyvinyl alcohol fibers and method for producing them
US20050032450A1 (en) * 2003-06-04 2005-02-10 Jeff Haggard Methods and apparatus for forming ultra-fine fibers and non-woven webs of ultra-fine spunbond fibers
US20050079781A1 (en) * 2003-10-09 2005-04-14 Kuraray Co., Ltd. Nonwoven fabric composed of ultra-fine continuous fibers, and production process and application thereof
US20060057350A1 (en) * 2002-10-23 2006-03-16 Takashi Ochi Nanofiber aggregate, polymer alloy fiber, hybrid fiber, fibrous structures, and processes for production of them
US20060213829A1 (en) * 2005-03-25 2006-09-28 Rutledge Gregory C Production of submicron diameter fibers by two-fluid electrospinning process
US20060292369A1 (en) * 2005-03-10 2006-12-28 Rutledge Gregory C Superhydrophobic fibers and methods of preparation and use thereof
WO2008047542A1 (fr) * 2006-09-28 2008-04-24 Japan Vilene Company, Ltd. Séparateur de batterie alcaline, procédé de production de celui-ci et batteries alcalines
US7438777B2 (en) * 2005-04-01 2008-10-21 North Carolina State University Lightweight high-tensile, high-tear strength bicomponent nonwoven fabrics
US20100080993A1 (en) * 2008-09-29 2010-04-01 Marc Privitera Electrospun Functional Fibers
US7767297B2 (en) * 2007-07-30 2010-08-03 Idemitsu Technofine Co., Ltd. Fiber, fiber assembly, and fiber producing method
US8889573B2 (en) * 2008-09-04 2014-11-18 Daiwabo Holdings Co., Ltd. Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5895710A (en) * 1996-07-10 1999-04-20 Kimberly-Clark Worldwide, Inc. Process for producing fine fibers and fabrics thereof
US20020127939A1 (en) * 2000-11-06 2002-09-12 Hwo Charles Chiu-Hsiung Poly (trimethylene terephthalate) based meltblown nonwovens
JP4238119B2 (ja) 2003-11-25 2009-03-11 日本バイリーン株式会社 繊維集合体の製造方法及びその製造装置
JP2006069142A (ja) * 2004-09-06 2006-03-16 Teijin Techno Products Ltd 複合繊維構造体およびその製造方法
JP4777760B2 (ja) * 2005-12-01 2011-09-21 株式会社Ｓｎｔ 網目状構造体を含む複合構造体
JP4778797B2 (ja) 2006-01-25 2011-09-21 株式会社Ｅｓｐｉｎｅｘ ナノ繊維
JP2007239114A (ja) * 2006-03-06 2007-09-20 Univ Of Fukui 溶融型静電紡糸方法及び極細繊維
JP5069431B2 (ja) * 2006-06-30 2012-11-07 帝人ファイバー株式会社 複合繊維及び多スリット繊維
JP5140886B2 (ja) * 2007-05-07 2013-02-13 帝人株式会社 複合繊維構造体
JP2009024295A (ja) * 2007-07-20 2009-02-05 Tomoegawa Paper Co Ltd エレクトロデポジション装置、構造体の製造方法及びそれから製造される構造体

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5814404A (en) * 1994-06-03 1998-09-29 Minnesota Mining And Manufacturing Company Degradable multilayer melt blown microfibers
US6552123B1 (en) * 1998-12-16 2003-04-22 Kuraray Co., Ltd. Thermoplastic polyvinyl alcohol fibers and method for producing them
US20020100725A1 (en) * 2001-01-26 2002-08-01 Lee Wha Seop Method for preparing thin fiber-structured polymer web
US20060057350A1 (en) * 2002-10-23 2006-03-16 Takashi Ochi Nanofiber aggregate, polymer alloy fiber, hybrid fiber, fibrous structures, and processes for production of them
US20050032450A1 (en) * 2003-06-04 2005-02-10 Jeff Haggard Methods and apparatus for forming ultra-fine fibers and non-woven webs of ultra-fine spunbond fibers
US20050079781A1 (en) * 2003-10-09 2005-04-14 Kuraray Co., Ltd. Nonwoven fabric composed of ultra-fine continuous fibers, and production process and application thereof
US20060292369A1 (en) * 2005-03-10 2006-12-28 Rutledge Gregory C Superhydrophobic fibers and methods of preparation and use thereof
US20060213829A1 (en) * 2005-03-25 2006-09-28 Rutledge Gregory C Production of submicron diameter fibers by two-fluid electrospinning process
US7438777B2 (en) * 2005-04-01 2008-10-21 North Carolina State University Lightweight high-tensile, high-tear strength bicomponent nonwoven fabrics
WO2008047542A1 (fr) * 2006-09-28 2008-04-24 Japan Vilene Company, Ltd. Séparateur de batterie alcaline, procédé de production de celui-ci et batteries alcalines
US8486554B2 (en) * 2006-09-28 2013-07-16 Japan Vilene Company, Ltd. Alkaline battery separator, process for production thereof and alkaline batteries
US7767297B2 (en) * 2007-07-30 2010-08-03 Idemitsu Technofine Co., Ltd. Fiber, fiber assembly, and fiber producing method
US8889573B2 (en) * 2008-09-04 2014-11-18 Daiwabo Holdings Co., Ltd. Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof
US20100080993A1 (en) * 2008-09-29 2010-04-01 Marc Privitera Electrospun Functional Fibers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Physical Testing of Plastics, pp 185-189, T.R. Crompton, copyright 2012 *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110003144A1 (en) * 2006-11-14 2011-01-06 Philip John Brown Capillary-channeled polymer fibers modified for defense against chemical and biological contaminants
US20110177395A1 (en) * 2008-09-04 2011-07-21 Daiwabo Holdings Co., Ltd. Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof
US8889573B2 (en) 2008-09-04 2014-11-18 Daiwabo Holdings Co., Ltd. Fiber assembly, composite of electro conductive substrate and fiber assembly, and production methods thereof
US20130085212A1 (en) * 2010-05-04 2013-04-04 Consejo Superior De Investigaciones Cientificas (Csic) Procedure for the obtainment of nanocomposite materials
US9142815B2 (en) 2010-06-21 2015-09-22 Kolon Industries, Inc. Method for manufacturing a porous nanoweb
JP2012112067A (ja) * 2010-11-24 2012-06-14 Univ Of Fukui 繊維マットの製造方法、及び、繊維マット
US20130017748A1 (en) * 2011-07-15 2013-01-17 Samsung Electro-Mechanics Co., Ltd. Porous sheet and method for manufacturing the same
US20140357144A1 (en) * 2011-12-19 2014-12-04 Virginia Tech Intellectual Properties, Inc. Melt Electrospun Fibers Containing Micro and Nanolayers and Method of Manufacturing
WO2013157969A1 (fr) 2012-04-17 2013-10-24 Politechnika Łodzka Matériel médical pour reconstruction de vaisseaux sanguins, son procédé de fabrication et utilisation du matériel médical pour la reconstruction de vaisseaux sanguins
US11038240B2 (en) * 2012-10-23 2021-06-15 Cornell University Ceramic nanofiber separators
US20190123321A1 (en) * 2012-10-23 2019-04-25 Cornell University Ceramic nanofiber separators
US20150287967A1 (en) * 2012-10-23 2015-10-08 Cornell University Ceramic nanofiber separators
US20210273294A1 (en) * 2012-10-23 2021-09-02 Cornell University Ceramic nanofiber separators
US11769928B2 (en) * 2012-10-23 2023-09-26 Cornell University Ceramic nanofiber separators
JP2016089317A (ja) * 2014-11-11 2016-05-23 日本ポリプロ株式会社 溶融紡糸型エレクトロスピニング用プロピレン系樹脂組成物、およびそれを用いたプロピレン系極細繊維の製造方法、並びにその方法により製造されたプロピレン系極細繊維
JP2016125182A (ja) * 2015-01-08 2016-07-11 パナソニックＩｐマネジメント株式会社 不織布およびそれを用いた空気清浄機、ならびに不織布の製造方法
EP3444387A4 (fr) * 2016-04-11 2019-11-13 Kao Corporation Procédé de production de fibre ultrafine
US11174569B2 (en) 2016-04-11 2021-11-16 Kao Corporation Ultrafine fiber production method

Also Published As

Publication number Publication date
EP2221402A1 (fr) 2010-08-25
WO2009069759A1 (fr) 2009-06-04
CN101878331B (zh) 2012-06-20
CN101878331A (zh) 2010-11-03
EP2221402A4 (fr) 2011-01-12

Similar Documents

Publication Publication Date Title
US20100297443A1 (en) Ultrafine composite fiber, ultrafine fiber, method for manufacturing same, and fiber structure
JP4749511B2 (ja) 繊維集合物、導電性基材と繊維集合物との複合体及びそれらの製造方法
JP4558826B2 (ja) 極細複合繊維と極細繊維及びその製造方法、並びに繊維構造物
WO2007105479A1 (fr) Procede de filage electrostatique a l'etat fondu et fibre extra fine
EP2599908B1 (fr) Tissu non tissé, procédé et dispositif pour sa production
CN106661773B (zh) 高熔点树脂纤维及无纺布
JP2010275663A (ja) 繊維集合物及び熱接着不織布の製造方法
JP5593038B2 (ja) 極細複合繊維及びその製造方法、並びに繊維構造物
KR101948365B1 (ko) 극세 섬유 시트
JP5004774B2 (ja) 極細複合繊維及びその製造方法、並びに繊維構造物
JP5846621B2 (ja) 濾過材及びその製造方法
JP5540293B2 (ja) 紡糸方法、繊維マットの製造方法、紡糸装置、繊維、及び、繊維マット
JP6411900B2 (ja) Ｐｅｅｋファイバーの製造方法、ｐｅｅｋファイバー及び不織布
JP4185748B2 (ja) 不織布及びリチウムイオン二次電池用セパレータ
JP2013064203A (ja) ナノファイバーよりなる連続シートの製造方法
JP5804344B2 (ja) 繊維マットの製造方法、及び、繊維マット
JP2016030879A (ja) 海島複合繊維
JP5467895B2 (ja) 繊維集合物及びその製造方法
US11419970B2 (en) Blood filter
JP5671203B2 (ja) 耐熱性布帛
JP4476724B2 (ja) 延伸抽出繊維の製造方法、延伸抽出繊維、及び不織布
JP2004285509A (ja) 極細繊維及びこれを用いた不織布
JP2006028689A (ja) ポリオレフィン系極細高強度繊維及び不織布

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAIWABO POLYTEC CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAMISASA, TOSHIO;OGATA, NOBUO;SIGNING DATES FROM 20100527 TO 20100603;REEL/FRAME:024729/0019

Owner name: DAIWABO HOLDINGS CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KAMISASA, TOSHIO;OGATA, NOBUO;SIGNING DATES FROM 20100527 TO 20100603;REEL/FRAME:024729/0019

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION