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
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
  • D04H1/4282—Addition polymers
  • D04H1/4291—Olefin series
• • 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
  • D01D5/08—Melt spinning methods
• • 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
  • D04H3/007—Addition polymers
• • 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
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2501/00—Wearing apparel
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2509/00—Medical; Hygiene
  • D10B2509/02—Bandages, dressings or absorbent pads
  • D10B2509/026—Absorbent pads; Tampons; Laundry; Towels
• • 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
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/608—Including strand or fiber material which is of specific structural definition
• • 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
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/681—Spun-bonded nonwoven fabric

Definitions

• the present invention relates to a fibrous nonwoven fabric using a polyolefin material.
• polyolefin-based fibers and nonwoven fabrics are used for various applications, such as a disposable diaper, a sanitary product, a hygienic product, a clothing material, a bandage, a packaging material, etc.
• the fibers and nonwoven fabrics are often used for applications in which they come into direct contact with the body, and thus, in recent years, a required performance regarding good wear feeling to the body and hand touch feeling are being more increased. For this reason, with respect to the nonwoven fabrics, technological development related to an improvement of texture for good wear feeling, reduction in basis weight for weight reduction of products, and the like is demanded.
• PTL 1 discloses a spunbonded nonwoven fabric using a resin composition containing a low-crystalline polypropylene and a high-crystalline polypropylene; however, from the viewpoint of providing a nonwoven fabric having more excellent flexibility and higher strength, fibers constituting the nonwoven fabric are required to more reduce fiber diameter.
• the present invention has been made, and its object is to reduce fiber diameter of fibers constituting a fibrous nonwoven fabric using a polyolefin resin composition while preserving spinning stability.
• the present inventors made extensive and intensive investigations. As a result, it has been found that the above-described problem is solved by using a polyolefin resin composition having a specified crystallization rate.
• the present invention provides the following.
• a fibrous nonwoven fabric including a resin composition (C) containing a high-crystalline polyolefin (A) and a low-crystalline polyolefin (B), the fibrous nonwoven fabric satisfying the following conditions (1) and (2):
• a half-crystallization time (t a ) of the high-crystalline polyolefin (A) and a half-crystallization time (t b ) of the low-crystalline polyolefin (B) satisfy a relation of t a ⁇ t b ;
• a half-crystallization time (t c ) of the resin composition (C) is 1.2 to 2.0 times the half-crystallization time (t a ) of the high-crystalline polyolefin (A).
• the fibrous nonwoven fabric according to any one of the above items 1 to 4, wherein when molding the fibrous nonwoven fabric, molding is performed in a discharge amount per hole of 0.1 to 0.5 g/min. 6.
• a spunbonded nonwoven fabric constituted of fibers having a fineness of 0.2 to 1.0 denier.
• the reduction of diameter of fibers constituting the nonwoven fabric can be achieved while preserving spinning stability.
• a fibrous nonwoven fabric of a first invention is composed of a resin composition containing a high-crystalline polyolefin (A) and a low-crystalline polyolefin (B).
• the low-crystalline polyolefin (B) as referred to in the present invention means a crystalline polyolefin having a longer half-crystallization time than the high-crystalline polyolefin (A). That is, a half-crystallization time (t a ) of the high-crystalline polyolefin (A) and a half-crystallization time (t b ) of the low-crystalline polyolefin (B) satisfy a relation Of t a ⁇ t b .
• the high-crystalline polyolefin (A) which is used in the first invention is not particularly limited in terms of a kind thereof so long as it satisfies a condition (2) regarding a resin composition (C) as described later.
• Examples thereof include polyethylene, a propylene homopolymer, an ethylene-propylene copolymer, an ethylene- ⁇ -olefin copolymer, a propylene- ⁇ -olefin copolymer, an ⁇ -olefin homopolymer, a copolymer of plural ⁇ -olefins, and the like.
• This ⁇ -olefin is preferably one having 4 to 24 carbon atoms, more preferably one having 4 to 12 carbon atoms, and especially preferably one having 4 to 8 carbon atoms.
• its initial elastic modulus is preferably 500 to 2,000 MPa, more preferably 600 to 2,000 MPa, and still more preferably 700 to 1,800 MPa.
• the initial elastic modulus as referred to in this description is one measured by the following measuring method.
• a press sheet having a thickness of 1 mm was fabricated.
• a test piece was sampled from the resulting press sheet in conformity with JIS K7113 (2002) No. 2-1/2.
• a tensile tester (AUTOGRAPH AG-1, manufactured by Shimadzu Corporation)
• the test piece was set at an initial length L 0 of 40 mm, stretched at a tensile speed of 100 mm/min, and measured for a strain and a load in the stretching process, and the initial elastic modulus was calculated according to the following expression.
• the half-crystallization time (t a , t b , and t c ) as referred to in this description means one measured by the following measuring method.
• the measurement is made using FLASH DSC (manufactured by Mettler-Toledo International Inc.) in the following method.
• a sample is melted by heating at 230° C. for 2 minutes and then cooled to 25° C. at a rate of 2,000° C./sec, and a time change of heating value in an isothermal crystallization process at 25° C. is measured.
• the above-described low-crystalline polyolefin (B) is not particularly limited in terms of a kind thereof so long as it has a longer half-crystallization time than the high-crystalline polyolefin (A) as described above.
• Examples thereof include polyethylene, a propylene homopolymer, an ethylene-propylene copolymer, a propylene- ⁇ -olefin copolymer, an ⁇ -olefin homopolymer, a copolymer of plural ⁇ -olefins, and the like.
• This ⁇ -olefin is preferably one having 4 to 24 carbon atoms, more preferably one having 4 to 12 carbon atoms, and especially preferably one having 4 to 8 carbon atoms.
• its initial elastic modulus is preferably 5 MPa or more and less than 500 MPa, more preferably 10 to 400 MPa, and still more preferably 20 to 300 MPa.
• the initial elastic modulus of the low-crystalline polyolefin (B) can be measured in the same manner as that in the above-described high-crystalline polyolefin (A).
• the low-crystalline polyolefin (B) is preferably a low-crystalline polypropylene satisfying the following condition (a), and more preferably a low-crystalline polypropylene satisfying all of the following conditions (a) to (f).
• the above-described low-crystalline polypropylene its [mmmm] (mesopentad fraction) is 20 to 60 mol %.
• the [mmmm] is 20 mol % or more, solidification after melting is fast, stickiness of the fibers is suppressed, and attachment onto a wind-up roll is hardly caused, and therefore, continuous molding becomes easy.
• the [mmmm] is 60 mol % or less, a degree of crystallization is lowered, and therefore, end breakage is hardly caused, and furthermore, a nonwoven fabric having a soft touch feeling is obtained.
• the [mmmm] of the above-described low-crystalline polypropylene is more preferably 30 to 50 mol %, and still more preferably 40 to 50 mol %.
• the above-described low-crystalline polypropylene its [rrrr]/(1 ⁇ [mmmm]) is preferably 0.1 or less.
• the [rrrr]/(1 ⁇ [mmmm]) is an index indicating the uniformity of regularity distribution of the low-crystalline polypropylene.
• the resultant does not become a mixture of a high-stereoregular polypropylene and an atactic polypropylene, as in the conventional polypropylene which is produced using an existent catalyst system, and stickiness is hardly caused.
• the [rrrr]/(1 ⁇ [mmmm]) of the above-described low-crystalline polypropylene is more preferably 0.05 or less, and still more preferably 0.04 or less.
• the above-described low-crystalline polypropylene its [rmrm] (racemic-meso-racemic-meso pentad fraction) is preferably more than 2.5 mol %. If the [rmrm] is 2.5 mol % or less, random properties of the low-crystalline polypropylene are reduced, the degree of crystallization is increased due to crystallization by an isotactic polypropylene block chain, end breakage is caused, and furthermore, a soft touch feeling is not obtained in the resulting nonwoven fabric.
• the [rmrm] of the above-described low-crystalline polypropylene is more preferably 2.6 mol % or more, and still more preferably 2.7 mol % or more. An upper limit thereof is usually about 10 mol %.
• the above-described low-crystalline polypropylene its [mm] (mesotriad fraction) ⁇ [rr] (racemic triad fraction)/[mr] (meso-racemic triad fraction) 2 is preferably 2.0 or less.
• the [mm] ⁇ [rr]/[mr] 2 indicates an index of random properties of the polymer, and when the [mm] ⁇ [rr]/[mr] 2 is smaller, the random properties become higher, the frequency of end breakage is reduced, and a nonwoven fabric having a soft touch feeling is obtained. When this value is 2.0 or less, end breakage is not caused in fibers obtained by spinning, and a nonwoven fabric having a good soft touch feeling is obtained.
• the [mm] ⁇ [rr]/[mr] 2 of the above-described low-crystalline polypropylene is more preferably more than 0.25 and 1.8 or less, and still more preferably 0.5 to 1.5.
• the weight average molecular weight of the above-described low-crystalline polypropylene is preferably 10,000 to 200,000.
• the weight average molecular weight is 10,000 or more, the viscosity of the low-crystalline polypropylene is not excessively low but is appropriate, and therefore, end breakage on the occasion of spinning is suppressed.
• the weight average molecular weight is 200,000 or less, the viscosity of the low-crystalline polypropylene is not excessively high, and spinnability is improved.
• the weight average molecular weight of the above-described low-crystalline polypropylene is more preferably 30,000 to 100,000, and still more preferably 40,000 to 80,000.
• the low-crystalline polypropylene which is used in the first invention its molecular weight distribution (Mw/Mn) is preferably less than 4.0.
• Mw/Mn molecular weight distribution
• the molecular weight distribution (Mw/Mn) of the above-described low-crystalline polypropylene is more preferably 3.0 or less, and still more preferably 2.5 or less.
• the low-crystalline polypropylene satisfying the above-described condition (a) may also be a copolymer using other comonomer than propylene so long as it satisfies the condition (2) regarding the resin composition (C) as described later.
• the amount of the comonomer is usually 2% by mass or less.
• the comonomer include ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, and the like. In the present invention, one or two or more kinds of these monomers can be used.
• the resin composition (C) which is a raw material of the fibrous nonwoven fabric of the first invention, contains the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B) as described above, and a half-crystallization time (t a ) of the resin composition (C) is 1.2 to 2.0 times the half-crystallization time (t a ) of the high-crystalline polyolefin (A).
• the half-crystallization time (t c ) is less than 1.2 times the half-crystallization time (t a )
• the crystallization rate of the resin composition (C) is fast, and on the occasion of melt molding of fibers, and the molten resin discharged from a nozzle is immediately crystallized, and therefore, end breakage is liable to occur, reducing the fiber diameter is difficulty achieved, and the fiber diameter is limited to 1.7 deniers or more.
• the half-crystallization time (t c ) is more than 2.0 times the half-crystallization time (t a )
• the fiber surface is sticky, roping (phenomenon in which the fibers stick to each other) is generated, and stable spinning cannot be achieved.
• the fibers become thick due to shrinkage, so that reducing the fiber diameter cannot be achieved, too.
• the half-crystallization time (t c ) is preferably 1.2 to 1.9 times, and more preferably 1.3 to 1.9 times the half-crystallization time (t a ).
• Examples of a method of controlling the half-crystallization time (t c ) of the resin composition (C) to 1.2 times or more the half-crystallization time (t a ) of the high-crystalline polyolefin (A) include a method of increasing a ratio of the low-crystalline polyolefin (B) in the combination of the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B); a method of changing the low-crystalline polyolefin (B) to one having a longer half-crystalline time (t b ); and the like.
• examples of a method of controlling the half-crystallization time (t c ) of the resin composition (C) to 2.0 times or less the half-crystalline time (t a ) of the high-crystalline polyolefin (A) include a method of decreasing a ratio of the low-crystalline polyolefin (B) in the combination of the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B); a method of changing the low-crystalline polyolefin (B) to one having a shorter half-crystalline time (t b ); and the like.
• the content of the high-crystalline polyolefin (A) in the above-described resin composition (C) is not particularly limited so long as it falls within the range where the condition (2) regarding the resin composition (C) can be satisfied.
• the contents of the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B) in order to satisfy the condition (2) regarding the resin composition (C) vary depending upon what kinds of polyolefins are selected with respect to the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B).
• the content of the high-crystalline polyolefin (A) in the above-described resin composition (C) is preferably 50 to 98% by mass, and more preferably 60 to 95% by mass.
• the content of the low-crystalline polyolefin (B) in the above-described resin composition (C) is preferably 2 to 50% by mass, and more preferably 5 to 40% by mass.
• the content of the low-crystalline polypropylene satisfying the above-described initial elastic modulus is preferably 2 to 35% by mass, and more preferably 5 to 30% by mass on the basis of a total sum of the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B).
• the above-described resin composition (C) may contain other thermoplastic resin and various additives, such as a release agent, etc. so long as it satisfies the above-described physical properties.
• thermoplastic resin examples include olefin-based polymers. Specifically, examples thereof include a polypropylene, a propylene-ethylene copolymer, a propylene-ethylene-diene copolymer, a polyethylene, an ethylene/ ⁇ -olefin copolymer, an ethylene-vinyl acetate copolymer, a hydrogenated styrene-based elastomer, and the like. These may be used solely or may be used in combination of two or more kinds thereof.
• the above-described release agent refers to an additive for improving release properties such that the molded nonwoven fabric does not attach to a roll or a conveyor of a molding machine.
• the release agent which is contained in the resin composition (C) is called an internal release agent, and the internal release agent refers to an additive for improving release properties of the nonwoven fabric upon being added to the resin raw material.
• An external release agent as described later refers to an additive for improving release properties of the nonwoven fabric upon being coated directly on a roll or a conveyor of a molding machine.
• Examples of the internal release agent include organic carboxylic acids or metal salts thereof, aromatic sulfonic acid salts or metal salts thereof, organic phosphoric acid compounds or metal salts thereof, dibenzylidene sorbitol or derivatives thereof, rhodinic acid partial metal salts, inorganic fine particles, imidic acids, amide acids, quinacridones, quinones, and mixtures thereof.
• Examples of the metal in the above-described metal salt of an organic carboxylic acid include Li, Ca, Ba, Zu, Mg, Al, Pb, and the like.
• examples of the carboxylic acid include fatty acids, such as octylic acid, palmitic acid, lauric acid, stearic acid, behenic acid, montanic acid, 12-hydroxystearic acid, oleic acid, isostearic acid, ricinoleic acid, etc.; and aromatic acids, such as benzoic acid, p-t-b-benzoic acid, etc.
• Specific examples thereof include aluminum benzoate, aluminum p-t-butylbenzoate, sodium adipate, sodium thiophenecarboxylate, sodium pyrrolecarboxylate, and the like.
• dibenzylidene sorbitol or derivative thereof include dibenzylidene sorbitol, 1,3:2,4-bis(o-3,4-dimethylbenzylidene)sorbitol, 1,3:2,4-bis(o-2,4-dimethylbenzylidene)sorbitol, 1,3:2,4-bis(o-4-ethylbenzylidene)sorbitol, 1,3:2,4-bis(o-4-chlorobenzylidene)sorbitol, 1,3:2,4-dibenzylidene sorbitol, and the like. More specifically, GELOL MD and GELOL MD-R, all of which are manufactured by New Japan Chemical Co., Ltd., and the like are exemplified.
• Examples of the above-described rhodinic acid partial metal salt include PINECRYSTAL KM1600, PINECRYSTAL KM1500, and PINECRYSTAL KM1300, all of which are manufactured by Arakawa Chemical Industries, Ltd., and the like.
• Examples of the above-described inorganic fine particle include talc, clay, mica, asbestos, glass fiber, glass flake, glass bead, calcium silicate, montmorillonite, bentonite, graphite, aluminum powder, alumina, silica, diatomaceous earth, titanium oxide, magnesium oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate, barium sulfate, calcium sulfite, molybdenum sulfide, and the like.
• synthetic silica may be used as the silica, and examples thereof include SYLYSIA, manufactured by Fuji Silysia Chemical Ltd., MIZUKASIL, manufactured by Mizusawa Industrial Chemicals, Ltd., and the like.
• amide compound examples include erucic acid amide, oleic acid amide, stearic acid amide, behenic acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, stearyl erucamide, oleyl palmitamide, adipic acid dianilide, suberic acid dianilide, and the like.
• organic phosphoric metal salt examples include ADEKASTAB NA-11 and ADEKASTAB NA-21, all of which are manufactured by Adeka Corporation, and the like.
• These internal release agents can be used solely or in combination of two or more kinds thereof.
• the content of the internal release agent is preferably 10 to 10,000 ppm by mass, and more preferably 100 to 5,000 ppm by mass on the basis of the resin mixture from which the additives are eliminated.
• the content of the internal release agent is 10 ppm by mass or more, the function as the release agent is revealed, whereas when it is 10,000 ppm by mass or less, a balance between the function as the release agent and the economy becomes good.
• any conventionally known additives may be blended.
• the additive include a foaming agent, a crystal nucleating agent, a weatherability stabilizer, a UV absorber, a light stabilizer, a heat resistance stabilizer, an antistatic agent, a flame retardant, a synthetic oil, a wax, an electric property-improving agent, a slip inhibitor, an anti-blocking agent, a viscosity-controlling agent, a coloring inhibitor, a defogging agent, a lubricant, a pigment, a dye, a plasticizer, a softening agent, an age resistor, a hydrochloric acid-absorbing agent, a chlorine scavenger, an antioxidant, and an antitack agent, and the like.
• the nonwoven fabric of the first invention is one obtained by using the above-described resin composition (C) as the raw material, and preferably one produced by a spunbond method.
• the nonwoven fabric is produced in such a manner that a melt-kneaded resin composition is spun, stretched, and opened to form continuous long fibers, and subsequently, in a continued step, the continuous long fibers are accumulated on a moving collecting surface and entangled.
• a nonwoven fabric can be produced continuously, and the resulting nonwoven fabric has large strength because fibers constituting the nonwoven fabric are stretched continuous long fibers.
• Fibers can be produced by extruding a molten polymer, for example, from a large nozzle with several thousands of holes or a group of small nozzles having, for example, about 40 holes. After discharged from the nozzle, molten fibers are cooled by a cross-flow cooling air system, drawn away from the nozzle, and stretched by high-speed airflow. Generally, there are two kinds of air-damping methods, and the both use a venturi effect. In the first air-damping method, filaments are stretched by using a suction slot (slot stretching). This method is conducted by using the width of a nozzle or the width of a machine.
• filaments are stretched through a nozzle or a suction gun.
• the filaments formed through the above methods are collected to form a web on a screen (wire) or a hole forming belt.
• the web passes through a compression roll and then passes between heating calendar rolls, and the web is bounded in a portion where an embossment portion on one roll includes about 10% to 40% of the area of the web, thereby forming a nonwoven fabric.
• the fibers of the resulting fibrous nonwoven fabric are likely to become a fine fiber with 1.3 deniers or less; when it is 0.2 or less, the above-described fibers are likely to become a fine fiber with 1.0 denier or less; when it is 0.13 or less, the above-described fibers are likely to become a fine fiber with 0.8 deniers or less; and when it is 0.1 or less, the above-described fibers are likely to become a fine fiber with 0.6 deniers or less.
• the fibrous nonwoven fabric of the present invention by a spunbonded nonwoven fabric molding machine using a cabin system
• reducing the fiber diameter can be achieved to an extent that the fiber diameter is 1.0 denier or less.
• Resin temperature 200° C. to 270° C.
• Discharge amount per hole 0.3 g/min to 0.6 g/min
• Cabin pressure 4,500 Pa to 8,000 Pa
• Calendar temperature 100° C. to 150° C.
• Nip pressure 100 N/mm
• the fibers of the resulting fibrous nonwoven fabric are likely to become a fine fiber with 1.3 deniers or less; when it is 0.06 or less, the above-described fibers are likely to become a fine fiber with 1.0 denier or less; and when it is 0.05 or less, the above-described fibers are likely to become a fine fiber with 0.9 deniers or less.
• the external release agent is sprayed onto the above-described moving collecting surface.
• the resin composition (C) contains the internal release agent, though the external release agent may not be sprayed onto the above-described moving collecting surface, it may also be used in combination with the internal release agent from the standpoint of obtaining good release properties.
• the above-described external release agent include fluorine-based release agents and silicone-based release agents.
• fluorine-based release agent examples include DAIFREE, manufactured by Daikin Industries, Ltd. and FRELEASE, manufactured by Neos Company Limited.
• silicone-based release agent examples include SPRAY 200, manufactured by Dow Corning Toray Silicone Co., Ltd.; KF96SP, manufactured by Shin-Etsu Chemical Co., Ltd.; EPOLEASE 96, manufactured by Pelnox, Ltd.; KURE-1046, manufactured by Kure Engineering Ltd.; and the like. These can be used solely or in combination of two or more kinds thereof.
• silicone-based release agents are preferred.
• Examples of a method of spraying the external release agent onto the above-described moving collecting surface include a method by spraying and the like.
• the following fiber products can be given as examples of a fiber product using the fibrous non-woven fabric of the first invention. That is, a member for a disposable diaper, a stretchable member for a diaper cover, a stretchable member for a sanitary product, a stretchable member for a hygienic product, a stretchable tape, an adhesive bandage, a stretchable member for clothing, an insulating material for clothing, a heat insulating material for clothing, a protective suit, a hat, a mask, a glove, a supporter, a stretchable bandage, a base fabric for a fomentation, a non-slip base fabric, a vibration absorber, a finger cot, an air filter for a clean room, an electret filter subjected to electret processing, a separator, a heat insulator, a coffee bag, a food packaging material, a ceiling skin material for an automobile, an acoustic insulating material, a cushioning material, a speaker dust-proof
• a spunbonded nonwoven fabric according to a second invention is constituted of fibers having a fineness of 0.2 to 1.0 denier (preferably 0.2 to 0.8 deniers, more preferably 0.2 to 0.6 deniers, and still more preferably 0.3 to 0.6 deniers).
• spunbond woven fabric according to the second invention Details of the spunbond woven fabric according to the second invention are the same as those in the fibrous nonwoven fabric according to the first invention, except that the spunbond woven fabric is not limited to one composed of the resin composition (C) containing the high-crystalline polyolefin (A) and the low-crystalline polyolefin (B) as described above.
• the spunbond woven fabric according to the second invention can be suitably produced by the spunbond method (production condition 1) using the above-described ejector system.
• L-MODU low-crystalline polypropylene
• S901 low-crystalline polypropylene
• NOVATEC SA-03 manufactured by Japan Polypropylene Corporation
• the polypropylene was subjected to press molding to fabricate a test piece, the initial elastic modulus of which was then measured by a tensile test in conformity with JIS K-7113.
• a half-crystallization time measured by the following method using FLASH DSC (manufactured by Mettler-Toledo International Inc.) was used.
• the sample is melted by heating at 230° C. for 2 minutes and then cooled to 25° C. at a rate of 2,000° C./sec, and a time change of heating value in an isothermal crystallization process at 25° C. is measured.
• a time from start of the isothermal crystallization until the integrated value of heating value reaches 50% was defined as the half-crystallization time.
• the melt flow rate was measured under conditions at a temperature of 230° C. and at a load of 21.18 N in conformity with JIS K7210.
• the melting point (Tm ⁇ D) was determined from a peak top of a peak observed on the highest temperature side of a melt endothermic curve obtained by maintaining 10 mg of the sample at ⁇ 10° C. for 5 minutes and then increasing the temperature at a rate of 10° C./min by using a differential scanning calorimeter (DSC-7, manufactured PerkinElmer Inc.) under a nitrogen atmosphere.
• DSC-7 differential scanning calorimeter
• the weight average molecular weight (Mw) and the molecular weight distribution (Mw/Mn) were determined by a gel permeation chromatography (GPC) method. The following device and conditions were used in the measurement to obtain a weight average molecular weight as converted into polystyrene.
• RI detector for liquid chromatography WATERS 150C
• Solvent Mixed solvent of 1,2,4-trichlorobenzene and deuterated benzene in a ratio of 90/10 (volume ratio)
• Pulse repetition time 4 seconds
• the mesopentad fraction [mmmm], the racemic pentad fraction [rrrr], and the racemic-meso-racemic-meso pentad fraction [rmrm] are measured in conformity with the method proposed by A. Zambelli, et al., “Macromolecules, 6, 925 (1973)” and are a meso fraction, a racemic fraction, and a racemic-meso-racemic-meso fraction, respectively in the pentad units of the polypropylene molecular chain that are measured based on a signal of the methyl group in the 13 C-NMR spectrum.
• the mesopentad fraction [mmmm] increases, the stereoregularity increases.
• the triad fractions [mm], [rr], and [mr] were also calculated by the above-described method.
• the half-crystallization time was also measured by the above-described measuring method. Furthermore, a value obtained by dividing the half-crystallization time of the resin composition by the half-crystallization time of the high-crystalline polypropylene was defined as a relative crystallization time ratio. Results are shown in Table 2.
• the above-described resin composition was melt extruded at a resin temperature of 250° C. by using a single-screw extruder with a gear pump, and the molten resin was spun by discharging from a nozzle having a nozzle diameter of 0.3 mm (hole number: 841 holes) at a rate of 0.1 g/min in terms of a discharge amount per hole. Fibers obtained by spinning were sucked under the nozzle by an ejector at a pressure of 1.0 kg/cm 2 while cooling with air and laminated on a net surface moving at a line speed of 11 m/min. A fiber bundle laminated on the net surface was embossed at a nip pressure of 40 N/mm by using calendar rolls heated at 140° C. and then wound up by a wind-up roll.
• [T]/[E] obtained from a relation between the discharge amount per hole and the ejector pressure was 0.1.
• the resulting fibrous nonwoven fabric was measured for basis weight, fineness, breaking strength, breaking strain and static friction coefficient of the nonwoven fabric, and also subjected to cantilever measurement in the following measuring methods. Measurement results are shown in Table 2.
• the weight of the resulting nonwoven fabric of 5 cm ⁇ 5 cm was measured, thereby measuring the basis weight (g/m 2 ).
• Fineness(denier) p ⁇ n ⁇ ( d/ 2) 2 ⁇ 9,000 [1]
• test piece 200 mm in length ⁇ 50 mm in width of the resulting nonwoven fabric
• sampling was conducted in the machine direction (MD) and the cross-machine direction (CD) vertical to the machine direction.
• MD machine direction
• CD cross-machine direction
• the test piece was set at an initial length L 0 of 100 mm, stretched at a tensile speed of 300 mm/min, and measured for a stain and a load in the stretching process, and values of the load and the strain at the moment when the nonwoven fabric was broken were defined as breaking strength and breaking strain, respectively.
• test piece of 100 mm in length ⁇ 100 mm in width was fabricated from the resulting nonwoven fabric, and the cantilever test was conducted by using a cantilever tester having a slope having an incline angle of 45° in one end of a seating thereof.
• the test piece was slipped on the seating at a fixed speed in the slope direction, and a movement distance of the nonwoven fabric at the moment when the test piece was bent and one end thereof came into contact with the slope was measured.
• the measurement was conducted in both of the machine direction (MD) and the cross-machine direction (CD) vertical to the machine direction.
• Example 2 A nonwoven fabric was molded and evaluated in the same manners as those in Example 1, except that in Example 1, the discharge amount per hole was changed to 0.2 g/min, the ejector pressure was changed to 4.0 kg/cm 2 , and the line speed was changed to 24 m/min. Results are shown in Table 2. At that time, [T]/[E] obtained from a relation between the discharge amount per hole and the ejector pressure was 0.05.
• Example 2 A nonwoven fabric was molded and evaluated in the same manners as those in Example 1, except that in Example 1, the discharge amount per hole was changed to 0.3 g/min, the ejector pressure was changed to 2.0 kg/cm 2 , and the line speed was changed to 35 m/min. Results are shown in Table 2. At that time, [T]/[E] obtained from a relation between the discharge amount per hole and the ejector pressure was 0.15.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 1, except that in Example 1, the addition amount of the low-crystalline polypropylene was changed to 1% by mass, the discharge amount per hole was changed to 0.5 g/min, the ejector pressure was changed to 2.0 kg/cm 2 , and the line speed was changed to 54 m/min. Results are shown in Table 2. At that time, [T]/[E] obtained from a relation between the discharge amount per hole and the ejector pressure was 0.25.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 1, except that in Example 1, the low-crystalline polypropylene was not added, the discharge amount per hole was changed to 0.5 g/min, the ejector pressure was changed to 2.0 kg/cm 2 , and the line speed was changed to 54 m/min. Results are shown in Table 2. At that time, [T]/[E] obtained from a relation between the discharge amount per hole and the ejector pressure was 0.25.
• L-MODU low-crystalline polypropylene
• PP3155 manufactured by ExxonMobil
• the above-described resin composition was melt extruded at a resin temperature of 250° C. by using a single-screw extruder with a gear pump, and the molten resin was spun by discharging from a nozzle having a nozzle diameter of 0.6 mm (hole number: 5,800 holes/m) at a rate of 0.47 g/min in terms of a discharge amount per hole. Fibers obtained by spinning were sucked under the nozzle by a cooling air duct at a cabin pressure of 8,000 Pa while cooling with air and laminated on a net surface moving at a line speed of 180 m/min. A fiber bundle laminated on the net surface was embossed at a nip pressure of 100 N/mm by using calendar rolls heated at 140° C. and then wound up by a wind-up roll.
• “[T]/[C] ⁇ 1,000” obtained from a relation between the discharge amount per hole and the cabin pressure was 0.06.
• the resulting nonwoven fabric was measured for basis weight, fineness, breaking strength, breaking strain and static friction coefficient of the nonwoven fabric, and also subjected to cantilever measurement in the above-described measuring methods. Measurement results are shown in Table 3.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 4, except that in Example 4, the cabin pressure was changed to 6,500 Pa. Results are shown in Table 3. At that time, [T]/[C] ⁇ 1,000 obtained from a relation between the discharge amount per hole and the cabin pressure was 0.07.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 4, except that in Example 4, 15 parts by mass of the low-crystalline polypropylene and 85 parts by mass of the high-crystalline polypropylene B were mixed, and the erucic acid amide was not added, thereby preparing a resin composition; the cabin pressure was changed to 7,500 Pa; and the line speed was changed to 150 m/min. Results are shown in Table 3. At that time, [T]/[C] ⁇ 1,000 obtained from a relation between the discharge amount per hole and the cabin pressure was 0.05.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 6, except that in Example 6, the cabin pressure was changed to 6,000 Pa. Results are shown in Table 3. At that time, [T]/[C] ⁇ 1,000 obtained from a relation between the discharge amount per hole and the cabin pressure was 0.06.
• L-MODU low-crystalline polypropylene
• PP3155 manufactured by Exxon Mobil Corporation
• the above-described resin composition was melt extruded at a resin temperature of 245° C. by using a single-screw extruder with a gear pump, and the molten resin was spun by discharging from a nozzle having a nozzle diameter of 0.6 mm (hole number: 5,800 holes/m) at a rate of 0.40 g/min in terms of a discharge amount per hole. Fibers obtained by spinning were sucked under the nozzle by a cooling air duct at a cabin pressure of 5,500 Pa while cooling with air and laminated on a net surface moving at a line speed of 530 m/min.
• a fiber bundle laminated on the net surface was embossed at a nip pressure of 100 N/mm by using calendar rolls heated at 146° C. and then wound up by a wind-up roll.
• “[T]/[C] ⁇ 1,000” obtained from a relation between the discharge amount per hole and the cabin pressure was 0.07.
• the resulting nonwoven fabric was measured for basis weight, fineness, breaking strength, breaking strain and static friction coefficient of the nonwoven fabric, and also subjected to cantilever measurement in the above-described measuring methods. Measurement results are shown in Table 3.
• L-MODU low-crystalline polypropylene
• MOPLEN HP561S manufactured by LyondellBasell, MFR: 33 g/10 min, melting point: 163° C.
• the above-described resin composition was melt extruded at a resin temperature of 240° C. by using a single-screw extruder with a gear pump, and the molten resin was spun by discharging from a nozzle having a nozzle diameter of 0.6 mm (hole number: 5,800 holes/m) at a rate of 0.57 g/min in terms of a discharge amount per hole. Fibers obtained by spinning were sucked under the nozzle by a cooling air duct at a cabin pressure of 6,000 Pa while cooling with air and laminated on a net surface moving at a line speed of 214 m/min.
• a fiber bundle laminated on the net surface was embossed at a nip pressure of 70 N/mm by using calendar rolls heated at 136° C. and then wound up by a wind-up roll.
• “[T]/[C] ⁇ 1,000” obtained from a relation between the discharge amount per hole and the cabin pressure was 0.10.
• the resulting nonwoven fabric was measured for basis weight, fineness, breaking strength, breaking strain and static friction coefficient of the nonwoven fabric, and also subjected to cantilever measurement in the above-described measuring methods. Measurement results are shown in Table 3.
• a nonwoven fabric was molded and evaluated in the same manners as those in Example 4, except that in Example 4, 1 part by mass of the low-crystalline polypropylene and 99 parts by mass of the high-crystalline polypropylene B were mixed, and the erucic acid amide was not added, thereby preparing a resin composition; the cabin pressure was changed to 4,500 Pa; and the line speed was changed to 220 m/min. Results are shown in Table 3. At that time, [T]/[C] ⁇ 1,000 obtained from a relation between the discharge amount per hole and the cabin pressure was 0.13.
• Example 4 A nonwoven fabric was molded and evaluated in the same manners as those in Example 4, except that in Example 4, only the high-crystalline polypropylene B was added as the raw material resin without adding the low-crystalline polypropylene and the erucic acid amide; the cabin pressure was changed to 4,500 Pa; and the line speed was changed to 220 m/min. Results are shown in Table 3. At that time, [T]/[C] ⁇ 1,000 obtained from a relation between the discharge amount per hole and the cabin pressure was 0.14.
• a resin composition was prepared by mixing 25 parts by mass of a low-crystalline polypropylene (“L-MODU (a registered trademark) S901”, manufactured by Idemitsu Kosan Co., Ltd., MFR: 50 g/10 min, melting point: 70° C.) and 75 parts by mass of the high-crystalline polypropylene C (“MOPLEN HP561S”, manufactured by LyondellBasell, MFR: 33 g/10 min, melting point: 163° C.) without adding erucic acid amide.
• L-MODU low-crystalline polypropylene
• S901 low-crystalline polypropylene
• MFR 50 g/10 min, melting point: 70° C.
• MOPLEN HP561S manufactured by LyondellBasell, MFR: 33 g/10 min, melting point: 163° C.
• the above-described resin composition was melt extruded at a resin temperature of 236° C. by using a single-screw extruder with a gear pump, and the molten resin was spun by discharging from a nozzle having a nozzle diameter of 0.6 mm (hole number: 5,800 holes/m) at a rate of 0.57 g/min in terms of a discharge amount per hole. Fibers obtained by spinning were sucked under the nozzle by a cooling air duct at a cabin pressure of 5,500 Pa while cooling with air and laminated on a net surface moving at a line speed of 215 m/min.
• a fiber bundle laminated on the net surface was embossed at a nip pressure of 90 N/mm by using calendar rolls heated at 134° C. and then wound up by a wind-up roll.
• [T]/[C] ⁇ 1,000” obtained from a relation between the discharge amount per hole and the cabin pressure was 0.10.
• the resulting nonwoven fabric was measured for basis weight, fineness, breaking strength, breaking strain and static friction coefficient of the nonwoven fabric, and also subjected to cantilever measurement in the above-described measuring methods. Measurement results are shown in Table 3.
• the fibrous nonwoven fabric of the present invention is extremely small in fiber diameter and good in hand touch feeling and is especially preferably used for hygienic materials, such as a paper diaper, etc.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=51262392

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (8)

Citations (3)

Family Cites Families (6)

• 2014
  • 2014-01-30 JP JP2014559756A patent/JP6507442B2/ja active Active
  • 2014-01-30 WO PCT/JP2014/052164 patent/WO2014119687A1/fr active Application Filing
  • 2014-01-30 EP EP14745725.3A patent/EP2952617B1/fr active Active
  • 2014-01-30 US US14/763,994 patent/US20150368836A1/en not_active Abandoned
  • 2014-01-30 CN CN201480006510.8A patent/CN104937155B/zh active Active

Patent Citations (3)

Also Published As

Similar Documents

Legal Events