TW201245519A - Fine polypropylene fibers and a method for their production - Google Patents

Abstract

The present application relates to fine polypropylene fibers as well as to a method for the production of such fine polypropylene fibers. Further, the present application relates to nonwovens comprising such fine polypropylene fibers.

Description

201245519 VI. Description of the Invention: [Technical Field of the Invention] Fine Polypropylene Fiber The present invention relates to a fine polypropylene fiber and a method of producing such an olefin fiber. Further, the present invention relates to a nonwoven comprising such fine aggregates. [Prior Art] The unique combination of mechanical and chemical properties of polypropylene and good processability has made polypropylene a useful application for a wide range of applications (eg, in the construction and agricultural industries, for cleaning and medical articles, carpets). Preferred for fibers and nonwovens of fibers and fabrics. 'This success is largely due to the discovery that it allows the production of solid poly(tetra) polymerization catalysts at industrially interesting costs. 'Stomach polymerization catalysts are: Ziegler' Natta catalysts, ie transition metal coordination elements Catalyst:: A catalyst containing a titanium compound. Polypropylene made with Ziegler-Natta catalysts in the fiber and the benefits of the group from the ..., everything in terms of acceptable properties, although for some applications such as spunbond or meltblown 'they need Further modification, for example by reducing #cracking to deuterate the molecular weight distribution and increase the solution flow index. Recently, polypropylene-based (manually referred to as metallocene polypropylene) manufactured by metallocene-based polymerization catalysts has become commercially available and is increasingly used to make fibers, especially those produced by the (IV) process. In addition to a good combination of mechanical and physical properties, polypropylene produced by metallocene/propylene's using a backuller's nanocatalyst catalyst allows for the production of finer fibers (ie, with lower denier than 201245519). Polypropylene), polypropylene is of interest. In order to take full advantage of the possibility of making finer fibers and nonwovens including metallocene polyfibers, processors have had to invest in: ^1 New and high-cost equipment for juice. It is interesting to take measures such as the use of new equipment from the beginning of the door to make such finer fibers. Obviously, this has led processors to It is difficult to carry out trial runs and manufacturing test quantities, for example to explore market potential. Therefore, 'there is a need for such a method for producing fine polypropylene fibers: this side The process does not require a large investment and allows the manufacture of such polypropylene fibers and nonwovens having mechanical properties comparable to conventional polypropylene fibers and nonwovens. Thus, it is an object of the present invention to provide for the production of fine polypropylene fibers. The above method is applicable to existing equipment. It is a further object of the present invention to provide a method for producing fine polypropylene fibers which has a final fineness of 2 denier or less. A further object of the present invention is to provide A method for producing a nonwoven comprising such fine polypropylene fibers. It is a further object of the present invention to provide a method of producing a nonwoven characterized by improved softness. Further, it is an object of the present invention to provide A method for producing a nonwoven having improved mechanical properties. Further, it is an object of the present invention to provide a nonwoven having improved softness or improved mechanical properties or both. 201245519 Further, one of the present invention The aim is to provide a nonwoven for improved web coverage (web C0Ver_a£J, more ge) for a given helmet textile weight. SUMMARY OF THE INVENTION We have now found that any of these objectives (single or in any combination) can be achieved by providing the following methods for making fine polypropylene fibers. Accordingly, the present invention provides for the manufacture of finely divided two fibers and including the above The method of nonwoven fabric of polypropylene fibers, the fine polypropylene fibers on μ, +, ζ β are characterized by a fineness of at most 1.2 denier, and the above method comprises the following steps: (4) supplying the polypropylene composition to an extruder, the above polypropylene The lean renter comprises (iv) at least 5 〇 by weight of the total weight of the above polypropylene composition; metallocene polypropylene; () subsequently (5) extruding the above polypropylene composition to obtain a swellable polypropylene stream; (c) extruding the molten polypropylene stream of step (b) from a plurality of fine tongs of the die into a circular capillary, thereby obtaining a filiform polymerization fis (fi1 ament); and (d) subsequently 'Cooling the filament obtained in step (c) and reducing its fineness to the final fiber denier, and t in step (c), the temperature of the above molten polypropylene stream is at least t«** + iioc , which makes τ (four) based on IS0 314 6 determines the melting temperature of the above-mentioned gold-plated polypropylene. Furthermore, the present invention provides the use of the above process in the manufacture of a fine polypropylene fiber composed of a metallocene I propylene polypropylene composition comprising at least 5 Å by weight, 同, (1) characterized by the fiber produced therefrom The final titer is up to 95% of the final fineness of the fiber produced under phase conditions but at a maximum of τ "side melt polymer stream temperature, or (U) characterized by: in the step (〇, the die pressure is in Up to 80% of the die pressure at the same temperature but at a maximum of T "side melt polymer stream temperature, or (iii) characterized by: the elongation of the nonwoven as determined according to IS 〇 9 〇 73_3: 1989 is A nonwoven having substantially the same weight per unit surface (at least 1.5% of the elongation of the above nonwoven under the same conditions but at a maximum of T_ + i (manufactured at a molten polymer stream temperature of rc), or (iv It is characterized in that the tensile strength of the above-mentioned nonwovens determined according to ls 〇 9 〇 73_3:1 989 is a nonwoven having substantially the same basis weight (the above-mentioned nonwoven under the same conditions but at most T^) +1〇〇t molten polymer material At least 1% by weight of the tensile strength produced at a temperature is preferably at least 106%, or (v) characterized by: a bonding temperature is higher than that under the same conditions but at most Teas + 100t: The polypropylene fibers obtained at the stream temperature have a low bonding temperature of at least 2. (: wherein is the above-mentioned metallocene polypropylene densification temperature determined according to ISO 3146. The invention also provides polypropylene composed of a polypropylene composition The fiber, the above polypropylene composition comprises at least 50% by weight, based on the total weight of the above-mentioned polypropylene composition, of a metallocene propylene polymer which is round on the basic 6 201245519 and has a fineness of at most 1·2 denier. [Embodiment] For the purposes of the present invention, it can be used synonymously. For the purposes of the present invention, the terms "polypropylene," and "propylene polymer" are used in the terms 0. "Fiber," and "filament" are synonymous with In the context of the invention, the term "a metallocene-based polymerization catalyst produced by a metallocene is used to indicate that the term 'fine fiber' is used for the invention to mean the fineness of the most common. Fiber "Tedan", even more preferably at most i 05, the degree of denier is the most hl r. For the purposes of the present invention, the term "tetrahydrogenation," wherein ... 1 is converted to 4, 5, 6, 7-tetrahydroindenyl茚基. Number of clothing (M 2: full moon in the ' & propylene or polypropylene composition of the bluff flow root please (10), material in the 峨 * 216 疋〇 疋〇 fiber The polypropylene fiber of the invention includes (1) by A polypropylene component composed of a defined polypropylene composition, and (ii) an optional thermoplastic polymer component composed of a thermoplastic polymer composition as defined below. ^ Fibers composed only of the polypropylene component may also be used. Called "single component fiber 7 201245519 =. Fibers composed of a polypropylene component and one or more thermoplastic polymer components may also be referred to as "multicomponent fiber 7 罜 众 propylene components and fibers of a thermoplastic polymer component may also be referred to as " Bicomponent fibers, ie, 'terms' multicomponent fibers, are understood to include "bicomponent fibers,". Preferably, the polypropylene fibers of the present invention are monocomponent fibers or multicomponent fibers. More preferably, the polypropylene fibers of the present invention are monocomponent fibers or bicomponent fibers. Most preferably, the polypropylene fibers of the present invention are monocomponent fibers, i.e., consisting solely of the polypropylene component. In the multicomponent fiber of the present invention, the one or more thermoplastic polymer components described above preferably cover the above-mentioned multicomponent fiber ... 7 %, more preferably at least m: even more preferably at least 90%, still even more preferably at least The surface, and most preferably covers the entire surface of the multicomponent fiber described above. In the multicomponent fiber of the present invention, the one or more thermoplastic polymer components described above are preferably converted to a maximum weight%, more preferably at most 30% by weight, even more preferably at most 2% by weight based on the total weight of the multicomponent fibers. % and most preferably up to U) by weight Preferably, the one or more thermoplastic polymer components described above comprise at least $% by weight of the total weight of the multicomponent fibers. Polypropylene Composition The polypropylene composition comprising the polypropylene component included in the polypropylene fibers of the present invention comprises at least 50% by weight of the metallocene polypropylene as further defined below, relative to the total weight of the polypropylene composition described above. . Preferably, the above polypropylene composition comprises at least 60% by weight or 7% by weight, more preferably at least 2012 8 201245519% by weight or 90% by weight, even more preferably at least 95% by weight relative to the total weight of the above-mentioned polypropylene composition. % or 97% by weight and still even more preferably at least 99% by weight of the above metallocene polypropylene. Most preferably, the above polypropylene composition is composed of the above metallocene polypropylene. The remainder of the above polypropylene composition is preferably a thermoplastic polymer composition as defined below. Preferably, the above polypropylene composition comprises at least 96% by weight or 97.0% by weight. /. More preferably, at least 98.0% by weight or 98.5% by weight, even more preferably at least 99.0% by weight, still even more preferably at least 99.5% by weight, of the propylene monomer alone and most preferably composed of propylene monomer, % by weight relative to the total weight of the above polypropylene composition. Preferably, the metallocene polypropylene used herein has a melt flow index of at least 5. 〇dg/min, more preferably at least 10 dg/min, even more preferably at least 15 dg/min and most preferably at least 2 〇dg/min. Preferably, the metallocene polypropylene used herein has a maximum of 15 〇dg/min, more preferably at most 130 dg/min < 110 dg/min, even more preferably at most 90 dg/min or 70 dg/min, still more preferably at most 5 〇dg/ Min and most preferably a melt flow index of up to 40 dg/min. Preferably, the metallocene polypropylene used herein has a molecular weight distribution (MWD) of at least 1 Torr, more preferably at least 1.5 and most preferably at least 2. 〇, which is defined as Μ*/Μη, ie, weight average molecular weight and number average molecular weight This is Mn. 'Preferably, the metallocene polypropylene used herein has a molecular weight distribution defined as Μ*/Μ„ of up to 4〇, more preferably up to 3.5, even more preferably up to 3. 〇 and most preferably up to 2·8. It is determined by size exclusion chromatography (SEC) as described in the test method. 9 201245519 Preferably, the metallocene polypropylene used herein is characterized by high isotacticity, content of the cryptic pentad. Is a measure of isotacticity. Preferably, the content of the 五ίιη pentad is at least 9〇%, more preferably at least 95% and most preferably at least 97% β. The isotacticity can be as in the test method. It is determined by 13C-NMR analysis as described. Preferably, the metallocene polypropylene used herein is a copolymer of an arene and at least one comonomer, the at least one comonomer being different from propylene. For propylene and at least - (iv) a comonomer content of the above copolymer of the polymonomer, which is preferably at most 2.0% by weight, more preferably at most 15% by weight, even more preferably at most 1.0% by weight and most preferably at most 5% by weight, relative to The total weight of the above copolymer of propylene and at least one comonomer. Special Note 'This definition is intended to cover a comonomer content of 0% by weight. In other words, the above metallocene|propylene may be preferably a propylene homopolymer or a copolymer of propylene and at least one comonomer, the at least one comonomer being different from propylene and having a comonomer content as above definition. Preferred comonomers are selected from alpha olefins having one carbon atom. Preferred alpha-olefins are selected from the group consisting of ethylene, butene, pentene, hexenylene, and dimethyl]-pentene. More preferred alpha-olefins are ethylene, butadiene and di-carbene. Even more preferred alpha-olefins are bake and butadiene. The most preferred alpha olefin is ethylene. Preferably, the metallocene polypropylene used herein is characterized by a maximum melting temperature of (10) °C, and the melting temperature can be determined as described in the test method. Preferably, the metallocene polypropylene used herein is characterized by a percentage of 2, the insertion percentage, relative to the total number of propylene molecules in the poly 201245519 chain. Preferably, the above 2, the percentage of insertion is at most 丨·5%, more preferably at most 1.3/. It is even more preferably at most 1.2%, still more preferably at most 1.1% and most preferably eve. The above 2, the percentage of insertion can be determined as indicated in the test method. The polypropylene used herein may further include further additives such as an antioxidant, a light stabilizer, an acid scavenger, a lubricant, an antistatic additive, a nucleating ruthenium, and a colorant. An overview of such additives can be found in p 1Μ七丨cs

Additives Handbook- ed. H. Zweifel 2〇〇l ,

Hanser Publishers. The above-mentioned metallocene-based polymerization catalyst further includes a carrier and an activator. The above-mentioned metallocene-based polymerization catalyst is also preferably used in the case of a micronization polymerization or a copolymerization of propylene and at least one monomer. The metallocene-based polymerization catalyst of the scraper is well known and does not require detailed explanation. The above-mentioned metallocene I component can be described by the following formula: (M-R8)(Rb)(Rc)MX! X2 (1) Its "m, r, and r are defined as follows. From -aw)p...(SlRlR2)p_ and R and -(10)i, -(10)v)P+(PW)p~t) are...'(10)1) , medium ... each independently selected from the group consisting of gas, Cl_c di-c..., and its aryl 'having Cl-Cl. alkyl and c Γ, ^8 cycloalkyl, any two adjacent R (g) The square of the burnt group, or R (ie, two adjacent R1, two adjacent R2, or 201245519, R1 and adjacent R2) may form a cyclic saturated or unsaturated C4_Clfl ring; each R1 and R2 may in turn be substituted in the same manner. Preferably, pa is -(CWh- or -(SiR'R2)P_, wherein R1, R2 and p are as defined above. Most preferably, Γ is -(SiR'R2) -, where R1, R2 and p are as defined above. Examples include Me2C 'ethylene (_ch2-CH2-), Ph2C and Me2Si. Μ is a metal selected from the group consisting of Ti, Zr and Hf, preferably Zr. X1 and X2 are independently selected from the group consisting of halogen, hydrogen, and GC. An alkyl group, a c6-c15 aryl group, an alkaryl group having a Ci-Ci.alkyl group and a Ce-Cis aryl group. Preferably, χ1 and X2 are a halogen or a fluorenyl group. ... and IT are selected independently of each other and include a ring. Preferred examples of the pentadienyl ring are preferred examples of the fluorene, Br and BuCl() alkyl groups: methyl, ethyl, n-propyl, isopropyl I, n-butyl, isobutyl and tert-butyl. Preferred examples of the CS-C7 cycloalkyl group are a cyclopentyl group, a cyclohexyl group, a cycloheptyl group and a cyclooctyl group. Preferred examples of the CG-C15 aryl group are a phenyl group and a benzyl group. Preferred examples of the alkaryl group of a -C15 aryl group are a benzyl group (-(10)-(8) and -(CH2)2-Ph. Eight-column; ^1-signal, which may independently be an unsubstituted or substituted node group Or a tetrazirridyl group, or Rb may be a substituted cyclopentadienyl group> is a substituted or unsubstituted (tetra)yl group 4, preferably 'r may be the same' and may be selected from substituted cyclopentadienyl substituted anthracene Base, substituted thiol, 耒^" Substituted tetradecyl and substituted tetrahydrokistyl. 'Unsubstituted' means that all positions of ^ are occupied by hydrogen except for the position connected to the bridge. The substitution of a on the a finger refers to the position of the bridge 12 201245519 At least one other position on the outer 'Rb and Re is occupied by a substituent other than hydrogen

According to the above, the parent of I '丞 of the above substituents may be independently selected from Ci_Ci. alkyl,

Cs-C? Cycloalkyl, C6-Cl5 if its Phytophthora has a C丨-C丨〇 alkyl group and a Ce-C 〗 5 aryl aryl group, or any two j * adjacent Substituents can form cyclic saturated or unsaturated CU-Cio rings. The % pentylene group which may be independently selected from the group consisting of ammonia may be represented, for example, by the formula. The substituted node group can be represented, for example, by mR VR9RlflR11R12R13RH. The substituted tetraarylene group can be represented, for example, by the formula C9H4R1WR18. The substituted fluorenyl group can be represented, for example, by the general formula ^2, 2 bamboo 2 bamboo 26. a per-C1 alkyl group, a C5-C7 cycloalkyl group, a (6-〇5 aryl group, and a calcined aryl group having a Cl—Cl° group and a c...aryl group, or any two Adjacent R may form a cyclic saturated or unsaturated G^ ring; however, the condition is that all substituents are not hydrogen at the same time. Preferred metallocene components are those having C2 symmetry, or having Ci symmetry Those which are most preferably 0I have a C2 symmetry. Particularly suitable metallocene components are those whose mRC phase is followed by a substituted cyclopentadienyl group, preferably, the above cyclopentyl group in the oxime The dilute group is substituted at the 2, 3 or both positions 2 and 3. The particularly suitable metallocene component is also wherein Rb is the same and is selected from unsubstituted im-I, unsubstituted tetrahydroindenyl groups. And substituted fluorenyl and substituted tetrahydroindenyl. The substituted fluorenyl group is preferably substituted at the 2-position, 3-position, 4-position, 5-position oxime or any combination of these, more preferably 纟2, 4 bits or both are substituted at positions 2 and 4. The substituted four groups are preferably substituted at 2, 3 or both at positions 2 and 3. 13 201245519 A suitable metallocene component may also be the one in which t Rb is a substituted cyclophosphazene and fr is a substituted or unsubstituted pharmaceutically acceptable group. The above substituted cyclodecadienyl group is preferably at 2, 3 Position, 5 position or both at any combination of these, more preferably at the 3 or 5 position or both at the same position, most preferably at only 3 positions with a bulky substituent. The above bulky substituent may for example be ~CR27R28R29 or -SiR27R28R29, wherein R", r28 and r29 are independently selected from CbClD alkyl, Cs-C7 cycloalkyl, Ce-Cis aryl and have Cl-Cl. Alkyl and Ce~ClS aryl An alkaryl group, or any two adjacent R groups, may form a cyclic saturated or unsaturated G-CiO ring. Preferably, R28 and R29 are a fluorenyl group. Examples of particularly suitable metallocenes are: monomethyl Shi Xiyuan-based-bis(2-mercaptocyclopentadienyl) di-gasification, dimethyl-decanediyl-bis(3-mercaptocyclopentadienyl) di-gasification, dimethyl Shi Xitong Diki-bis(3-tert-butylcyclopentadienyl) digastric hammer, a sulfhydryl sylvestre-based-bis(3-tert-butyl-5-methylcyclopentadienyl) Zirconium dihydride, dimethyl Alkyldiyl-bis(2,4-dimethylcyclopentadienyl) digastric, dinonyldecanediyl-bis(nod) zirconium hydride, dimercaptodecanediyl-double 2-mercaptopurine) gasifier, dimethyl decanediyl-bis(3-methylindenyl) zirconium hydride, dimethyl decanediyl-bis(3-tert-butylfluorenyl) Dimethyl hydrazine, dimethyl decane diyl-bis (4, 7-dimethyl fluorenyl) di-vapor hydrazine, dimethyl decane diyl-bis (tetrahydro] quinone dimethane, dimethyl Zirconium diyl-bis(benzonitrile) zirconium hydride, 201245519 鍅Methyl succinated diyl-bis(3,3, _2-methyl phenyl) dimethyl sulphur —Double (4-stupyl) radical gasification, dimethyl sulphur-based dibasic silver methyl + stupid benzylidene-bis(nodular) di-vaporized hydrazine, ' # ' 亚乙Base-bis(tetrahydroindenyl)zirconium dihydride, isopropylidene tert-butylcyclopentadienyl) (fluorenyl) dichloroindolyl dichloride, tert-butyl-5-methylcyclopentane Dilute base) A cockroach. The above metallocene can be supported according to any method known in the art. In the case of its loading, the carrier used in the present invention may be: an organic solid, particularly a porous carrier such as talc, an inorganic oxide == carrier material such as a polyolefin. Preferably, the support material is a fine particle oxide. The polymerization of the propylene with one or more of the optional comonomers described above in the presence of a metallocene-based polymerization catalyst for obtaining the metallocene polypropylene can be carried out in one or more polymerization reactors according to known techniques. The metallocene polypropylene used in the present invention is preferably produced by polymerization in liquid propylene at a temperature in the range of from 201 to 150 °C. Preferably, the temperature is 6 &> c 12 〇 . The pressure can be atmospheric or higher. It is preferably 25-50 bar. The molecular weight of the polymer chain is regulated by the addition of hydrogen to the polymerization medium, and thus the melt flow of the above metallocene polypropylene is adjusted. Preferably, 'the above metallocene polypropylene is taken from one or more of the above polymerization reactors' without being carried out by thermal or chemical degradation and is often carried out for the polymerization of 15 201245519 using Ziegler-Natta catalysts. Post-polymerization treatment 'to reduce its molecular weight and / or narrow the vertical knife amount distribution. An example for chemical degradation is visbreaking, wherein the above described polypropylene is reacted with, for example, an organic peroxide at elevated temperatures, for example in an extruder or granulation plant. Thermoplastic Polymer Composition The thermoplastic polymer composition used herein may further comprise one or more thermoplastic polymers other than the metallocene polypropylene as defined above. Regardless of the amount of the components contained in the thermoplastic polymer composition, it is understood that the weight percentage of the m mesh to the total weight of the above thermoplastic polymer composition is 100% by weight in total. Preferred suitable thermoplastic polymers may be selected from the group consisting of polyolefins, polyamines, and polystyrenes, provided that the above polyolefins are not compatible with the above metallocene polypropylenes used herein. "Different from the above metallocene polypropylene, it is meant that the above polyolefin differs from the metallocene polypropylene defined above in at least one property. The above polyolefin may, for example, differ in composition, for example, based on an alpha olefin different from propylene. (such as ethylene, 1-butene, pentene, hexene or octene), or using a Ziegler-Natta catalyst instead of a metallocene-based polymerization catalyst or having different types of comon, or Different comonomer contents, or having different melt flow indices. Exemplary polyolefins for use herein are olefin homopolymers and copolymers of olefins with one or more comonomers. The above polyolefins may be random, Syndiotactic or isotactic. The above olefin may be, for example, ethylene, propylene, butadiene pentene, 1-hexene, 4-methyl-1-pentene or 1-octene, or 16 201245519 a cyclic olefin such as cyclopentane entropy, 3 & monomer ring blister or norbornne. The above copolymerization; the above olefin is selected and copolymerized to human olefin. Olefins as defined above An example of a suitable step is acetic acid (10)-c (, _CH=CH2) or ethylene glycol (H0_ch=CH2" 'which is itself unstable and tends to polymerize) ° a dilute hydrocarbon copolymer suitable for use in the present invention Examples are random copolymers of propylene and ethylene, random copolymers of propylene and butene, heterophasic copolymers of ruthenium and ethylene, ethylene-butene copolymer ethylene-hexene Copolymer, ethylene-octene copolymer, copolymer of ethylene and vinyl acetate (EVA) 'copolymer of ethylene and vinyl alcohol (ev〇h). An exemplary polyamine used herein can be characterized in that the polymer chain comprises a guanamine group (-NH-CO0)-). Polyamines useful in the present invention are preferably characterized by having one of the following chemical structures

H-[-NH-(CH2)n-C(=0)-]x-0H

H-[-NH-(CH2)m-NH-C(=〇HCH2)n-C(=0)-]x-OH

H-[-NH-CH2^QjCH2-NH-C(=0)-(CH2)n-C(=0)-]x-〇H wherein m and η may be independently selected from each other and are an integer from 1-20. Specific examples of suitable polyamines are polyamines 4, 6, 7, 8, 9, 1 , 11, 12, 46, 66, 610, 612 or 613. Another example of a suitable polyamine is Nylon-MXD6' which can be obtained by polycondensation of m-xylylenediamine and adipic acid, and is commercially available, for example, from Mitsubishi Gas Chemical Company. The exemplary polyesters used herein are preferably characterized by the following chemical structure 17 201245519 [-C( = 0)-C6H4-C( = 0)0-(CH2-CH2) „-0-]x where n is 1- An integer of 1 ,, and a preferred value is 1 or 2. Specific examples of suitable polyesters are polyethylene terephthalate (PET) and poly(p-butylene dicarboxylate) (PBT). The preferred polyester is a poly(hydroxy carboxylic acid). The melt flow index of the above polypropylene composition and the above thermoplastic polymer composition is preferably 'the same range as defined above for the above metallocene polypropylene. Manufacture of Fibers and Nonwovens The fibers of the present invention are produced by known manufacturing methods, such as those described in Polypropylene Handbook, ed. Nello Pasquini, 2nd Edition, Hanser, 2005, pp. 397-403. Page or F. Fourn6, Synthetische Fasern, Carl Hanser Verlag, 1 995' chapter 5. 2 or BC Goswami et al, Textile Yarns, John Wiley & Sons, 1 977, p. 371-376. Typically, fibers are manufactured as follows : making the polymer or in the extruder The composition is smelted, optionally passing the molten polymer through a melt pump to ensure a constant feed rate' and then extruding the molten polymer or molten polymer composition through a plurality of fine capillaries of the nozzle head To form fibers. These still molten fibers are simultaneously cooled and drawn to the final diameter by air, and finally collected. Optionally, the fibers thus obtained may be subjected to further stretching steps, preferably for the present invention. It is as-spun, that is, the fiber is subjected to a further stretching step. 18 201245519 Therefore

To the extruder; a method for producing fine polypropylene fibers comprising the steps of: providing a polypropylene stream as defined earlier in the present invention, (b) a polypropylene stream, followed by melt extrusion of the above polypropylene composition to obtain a melt. The propylene stream is extruded from a plurality of fines of the die to thereby obtain a melted polypropylene, C) the melt-polymerized, generally circular capillary of step (b) is extruded, and the fiber is produced; The filament obtained in step (4) is cooled and brought to the final fiber fineness to obtain a fine polypropylene fiber. It is necessary for the invention to melt the polypropylene material in step (4), which may also be referred to as "refining body temperature," (with "melting temperature, forming a pair", "), at least Τ® melting +11QV ^ /, medium τ® « is the melting temperature of the genus Polyurethane of the genus genus of the polypropylene composition included in the step (a). The above melting temperature is determined according to ISO 3146 as described in the test method. Preferably, the temperature of the molten propylene material, the ώ, and the field R is at least T ^ + 120 〇 C. It is not considered that the above-mentioned metallocene polypropylene is melted and added, and the 'degree of meaning is preferred. Is a molten polypropylene stream having a temperature of at least 26 (ΤΓ η i bu bUC and most preferably at least 265 t. In the case where the molten polypropylene stream comprises ultra-high polypropylene, the molten polymer stream The temperature is determined relative to the highest molten polypropylene included in the molten polypropylene stream described above. In addition to the increased smelting polycondensation, it is preferred to Hole production per minute (ie wear in awkward time) The amount of molten polypropylene that passes through the capillary of the die) is reduced to at most 95%, more preferably at most 9%, of the yield used in the manufacture of polypropylene fibers within the definition of J. ganolic into fine polypropylene fibers. Most preferably up to 85%.For the manufacture of multicomponent fibers, the above process comprises the steps of: U) providing a polypropylene composition as defined earlier in the present invention to an extruder; (a') will be as earlier as in the present invention The defined thermoplastic polymer composition and 1 are supplied to another extruder; (b) subsequently extruding the above polypropylene composition to obtain a molten polypropylene stream; (b') subsequently extruding the above thermoplastic polymer The composition obtains a molten thermoplastic polymer stream; (〇extruding the molten polypropylene stream of step (b) from a plurality of fine, generally circular, capillary tubes of the die, thereby obtaining a squeeze of smelting polypropylene (c) extruding the molten thermoplastic polymer stream of step (b,) through a plurality of fine openings surrounding the capillary of step (b), thereby obtaining an extrudate of the molten thermoplastic polymer; and (C Will be in the steps The extrudates obtained in (C) and (c') are combined to form an intermediate straight k single filament (Slngle fi lament) such that the extrudate of step (C,) covers at least 7 of the fine polypropylene fibers. Surface, and (d) Subsequently, the filament obtained in the previous step is cooled and its fineness is reduced to the final fiber fineness to obtain a fine polypropylene fiber. For the multicomponent fiber of the two components Manufacture, one or another additional composition of the composition, > additional polypropylene composition or another 20 201245519 can be fed sequentially to a separate extruder

Processing problems caused by hot, stuck together extruded filaments. The thermoplastic polymer composition is post-melt extruded to form the respective extrudates (C) and (c'). Thus, the present invention provides the above process for producing a metallocene propylene polymer comprising at least 50% by weight. Use in a fine polypropylene fiber composed of a polypropylene composition is characterized in that the final fineness is at most 95 of the final fineness of the fiber produced under the same conditions but at a temperature of the molten polypropylene stream of up to T$ & + 100t. %, preferably up to 90%, wherein τ(d) is the melting temperature of the above metallocene propylene polymer as determined by is 3146. In other words, the above method for producing a fine polypropylene fiber composed of a polypropylene composition comprising at least 5% by weight of a metallocene propylene polymer is characterized in that 'the final fineness is under the same conditions but at most T « a The final fineness of the fibers produced at a +1 〇〇C glaze polypropylene stream temperature is at most 95%, preferably at most 90%, wherein the melting temperature of the above metallocene propylene polymer is determined according to IS0 3146. It has been further noted that the manufacture of a fine polypropylene fiber composed of a polypropylene composition comprising at least 50% by weight of a propylene polymer of the metallocene 21 201245519 allows the die pressure to be drastically reduced in the step (C). Accordingly, the present invention provides the use of the above process in the manufacture of a fine polypropylene fiber composed of a polypropylene composition comprising at least 50% by weight of a metallocene propylene polymer, characterized in that in step (c), the die pressure Is up to 80% of the head pressure under the same conditions but at a molten polymer stream temperature of up to T ew + 1 〇〇〇c, wherein T ** is the above metallocene propylene polymer as determined according to IS 0 3146 Melting temperature. In other words, the above method for producing a fine polypropylene fiber composed of a polypropylene composition comprising at least 5% by weight of a metallocene propylene polymer is characterized in that in the step (c), the die pressure is Under the same conditions but at most T (four) + 100.最多@赖 Polymer flow temperature at a maximum of 80% of the die pressure 'where τ' is the melting temperature of the above metallocene propylene polymer determined according to IS〇3U6. The polypropylene nonwoven of the present invention may be passed through any suitable Method of manufacture. Such a method comprises a thermal bonding spunlacing method and a spunbonding method for staple fibers. A preferred method is spunbonding. In addition to the method steps (a)-(d) described above. And optionally, in addition to (a)-(c), the method for making a polypropylene-containing fabric comprising the present invention further comprises the steps of: collecting the polypropylene-free fibers in the carrier (e) in step (d) The obtained fines; and (two =:=(tetra)-ene fibers enter... 22 201245519 In order to manufacture a thermally bonded nonwoven, the fibers of the present invention are cut into staple fibers having a length of 5 to 3 min. Cutting the fibers for carding, ie collecting them on the carrier as a nearly continuous unreinforced (n〇nc〇ns〇iidated) web. In the final step, the above unreinforced is carried out by thermal or chemical entrapment. Net reinforcement, where the thermal axis is β preferred. & In the stabbing method, continuous fibers or staple fibers are randomly distributed on a carrier to form an unreinforced web, which is then reinforced and dried by a fine high-pressure water column. In the above-mentioned spinning method, the thermoplastic polymer is in the first extrusion. Melting out of the machine 'optionally by solution to ensure a constant feed rate, then wiping out a plurality of fine, usually circular, capillaries through the spinneret. For multi-component fibers such as two-component The fiber is made, the additional polymer blend is melted in a separate extruder, optionally through a melt of fruit, and then extruded through a fine, generally circular capillary entanglement surrounding the spinneret. :: a plurality of fine openings. The various extrudates are then combined to form an intermediate diameter of & filament (substantially still molten). Filament formation can be achieved by using a plurality of (usually several hundred) holes Single spinneret, or by using several smaller spinnerets (each with a correspondingly small number of holes). After exiting from the spinneret, the still molten filaments pass through the air stream Cold. Then pass high pressure air The diameter of the above filaments is rapidly reduced. The air velocity in the stretching step can be up to several hundred meters per minute. After stretching, the filaments are collected in a carrier such as a forming wire (f(4)(10) machi) or porous molding. Tape, thereby first forming unbound (汹. to (4) 23 201245519 net' and then passing it through a compaction roll and finally undergoing a bonding step. By heat bonding, hydroentanglement, acupuncture or chemical bonding Achieving a combination of fabrics 8 When used in the manufacture of nonwovens, the nonwovens made from the fine polypropylene fibers described above show surprising results. Polypropylene fibers produced at lower melt polypropylene flow temperatures. Comparing, the fine polypropylene fibers produced in accordance with the methods described in the present invention allow for the manufacture of nonwovens characterized by higher elongation or higher tensile strength or both. Accordingly, the invention provides the use of the above process in the manufacture of a nonwoven comprising polypropylene fibers comprised of a polypropylene composition comprising at least a weight percent metallocene propylene polymer, characterized in that, according to is〇9〇73_3: The elongation of the above nonwovens determined by i989 is a nonwoven having substantially the same weight per unit surface (the above nonwoven is produced under the same conditions but at a molten polymer stream temperature of at most τ^ + ι ° ° C). The elongation of the metal is at least 1.5%, preferably at least 110% and most preferably at least 115%, and the towel T(iv) is the melting temperature of the above metallocene propylene polymer determined according to iso 3146. In other words, the above method for producing a nonwoven comprising polypropylene fibers composed of a polypropylene composition comprising at least 5 Q% by weight of a metallocene propylene polymer is characterized by 'the above-mentioned nonwovens determined according to (10) Lake Elongation is the elongation of a nonwoven having substantially the same weight per unit of surface (the above nonwoven is produced under the same strip of the remainder but at a temperature of the molten polymer stream of up to ΐ(4)+100 °C). At least 105% of the rate, preferably at least

110% and most preferably at least 115%, the B-dry T «« is the melting temperature of the above metallocene propylene polymer determined according to IS 〇 3146. 24 201245519 Further, the present invention provides the above method for producing a nonwoven fabric comprising a polypropylene fiber composed of a polypropylene composition comprising at least 50% by weight of a metallocene propylene polymer,

The characteristics of the soldiers are: according to ISO 9073-3:1989, the above-mentioned | Jiang ", the tensile strength of the textile is a substantially similar basis weight of the benefits of rl, +, ^ • ...,, ' At least 104% of the tensile strength of a nonwoven fabric produced under the same conditions but at a turbulent temperature of a gauze + 峪嘁汆 compound at a maximum of T +1 〇〇 ° C, Preferably at least] nR. / #丄 , 主 〇 〇 6%, where Tu is the (iv) temperature of the above metallocene propylene polymer determined according to iS03146. In other words, the above method for producing a nonwoven comprising polypropylene fibers composed of a polypropylene composition comprising at least 50% by weight of a metallocene propylene polymer is characterized by the above-described determination according to IS〇W3 - I· The tensile strength of the nonwoven is that the right zith π progenitor (10) degree 有8 has substantially the same basis weight of the nonwoven material (the above-mentioned nonwoven material under the same conditions but in the most local τ_ + 1 溶 molten polymer material The tensile strength at the flow temperature is at least difficult, preferably at least 106%, wherein Τ(iv) is the melting temperature of the above metallocene propylene polymer determined according to (10) 3146. In the manufacture of nonwovens, it has been surprisingly noted that the finely divided polypropylene fibers herein allow for a reduction in the above-mentioned drilling temperature. Such a reduction is of interest to nonwoven manufacturers because it allows for higher manufacturing speeds in the bonding of polypropylene fibers. Accordingly, the present invention further provides the use of the above process in the manufacture of a nonwoven comprising polypropylene fibers consisting of a polypropylene composition comprising at least 50% by weight of a metallocene propylene polymer, characterized in that the bonding temperature is the same Under conditions, but at a molten polymer stream temperature of up to Tu + i〇〇t 25 201245519, the polypropylene fiber has a low bonding temperature of at least 2t, preferably at least 4. . And = is preferably to J 6C ' where τ (d) is the melting temperature of the above metallocene propylene polymer determined according to IS 〇 3i46. In other words, the method of manufacturing a non-woven fabric comprising a polypropylene composition comprising a polypropylene composition comprising at least 50% by weight of a metallocene propylene polymer is characterized in that the drilling temperature is higher than under the same conditions. The bonding temperature of the polypropylene fibers obtained at the temperature of the molten polymer stream of the most recent T* « + 1 〇〇c is at least 2t, preferably at least and most preferably at least 吖, wherein τ «« is determined according to IS0 3146 The melting temperature of the above metallocene propylene polymer. The composite may be formed of two or more nonwovens, at least one of the two or more nonwovens including the fine polypropylene fibers defined above. The above two or more kinds of nonwovens may be combined or they may be maintained uncoupled from each other, that is, 'only one is placed on top of the other. In particular, the above composite includes water according to the present invention. A thorn or spunbond nonwoven layer (S) or a meltblown nonwoven layer (M) according to the invention. The composite according to the invention may for example be SS, SSS, SMS, SMMSS, or spunlace or spunbond. Any combination of a layer of the melt and a layer of meltblown nonwoven. The first nonwoven or composite (the first nonwoven or composite described above comprises the fine polypropylene fibers defined above) and the film may be combined to form a laminate The above film is preferably a polyolefin film. The above laminate is formed by bringing the above-mentioned first nonwoven or composite together with the above film ' and by passing them through a pair of laminating rolls, for example. Laminating them to each other. The above laminate may further comprise a second nonwoven or composite on the face of the film opposite to the first nonwoven or the 26 201245519 composite, the second nonwoven or composite Things may, but need not, be in accordance with the present invention. In a preferred embodiment, the above film of the above laminate is a gas permeable, dense smoke film, thereby resulting in a laminate having gas permeable properties. The polypropylene fibers and filaments described herein can be used in carpets, Woven fabrics and nonwovens. The polypropylene spunbond nonwovens of the present invention and composites or laminates therewith can be used in sanitary and cleaning products such as diapers, feminine hygiene products and incontinence products for construction and Agricultural applications, medical covers and gowns, such as protective clothing, laboratory clothing, rags, etc. in cleaning and industrial applications. Test methods Melt flow index (MFI) for polypropylene and polypropylene compositions according to IS 〇3 Condition L, measured at 2 30 ° C and 2.16 kg. Molecular weight was determined by size exclusion chromatography (SEC) at elevated temperature (145 ° C.) 10 mg of polypropylene or polyethylene sample at i6 ° ° c It was dissolved in i〇mi three gas (Dingye grade) for 1 hour. The analysis conditions of GPCV 2000 from WATERS were: ''Injection volume: +/- 400 v 1

''Automatic sample preparation and syringe temperature: 1 60 ° C

~ 杈 Temperature: 145 ° C ~ Detector temperature: 16 〇. 〇

'杈 Settings: 2 Shodex AT-806MS and 1 Styragel HT6E 27 201245519 One flow rate: lml/min - Detector: Infrared detector (2800-3000^11-1) - Calibration: narrow standard for polystyrene ( Commercially available) - Calculation for polypropylene: based on the Mark_H〇uwink relationship 〇〇 gl〇(Mpp) = 1〇. (^) — 〇.25323); truncated at Mpp = 1 000 at the low molecular weight end. The molecular weight distribution (MWD) is then calculated as Mw/Mn. The dimethyl stearate (XS) (ie, the xylene soluble fraction) is determined as follows: 4.5 5.5 g of the propylene polymer is weighed and placed in a flask and the dimethyl ester is added to heat the above-mentioned one by stirring to reflux 4 5 minute. Continue to mix 1 5 knives without heating. The flask was then placed in a constant temperature bath set at 2 5 ° C for 1 hour. The solution was filtered through braided No. 4 filter paper and 100 ml of cold agent was collected. The solvent was then evaporated and the residue was dried and weighed. However: the percentage of xylene solubles ("xs") (ie the amount of xylene soluble fraction) is calculated according to the following formula: XS (early weight %) = (the initial total weight of the residue 300) The weight is the same unit, for example in grams. Using a 4_Hz Bruker surface spectrometer, the intensity of the letter in the spectrum is proportional to the total number of slave atoms in the sample. - NMR analysis of the conditions of β p-media mm ^ β-like, known to the skilled person, and including, for example, sufficient relaxation time, 箄 间 寺. Practice, the signal intensity is obtained by its integral, ie the corresponding area is 0, nnA Known Assets: Proton decoupling, 4000 scans per spectrum, pulse repetition delay of 2 sec seconds r and spectral width of 26000 Hz. 28 201245519 The sample was prepared by dissolving a sufficient amount of polymer in 13 〇 ° c in 1'2,4-trichlorobenzene (TCB' 99% 'spectrum level), and occasionally agitate to homogenize the sample' after adding hexa-substituted benzene (CeDe, spectral grade) and a small amount of hexamethyl Shixi Oxygen (HMDS '99. 5+%), of which HMDS is used as For example, about 20 mg of the polymer is dissolved in 2. Om 1 TCB, followed by 0.5 ml of C6D6 and 2-3 drops of HMDS. After the data acquisition, the 'chemical shift reference refers to the value of 2. 〇 3 ppm. The signal of the standard HMDS. The isotacticity is determined by 13C-NMR analysis of the entire polymer. The published data is used in the spectral region of the methyl group (eg A.

Razavi, Macromol. Symp., Vol. 89, pp. 345-367) identifies signals corresponding to the quintuple mmmm, mmmr, mmrr and mrrm. Only the quintuple mmmm, mmmr, mmrr, and mrrm are considered because the strength of the signal corresponding to the remaining quintuple is weak. The signal associated with the mmrr quintuple is corrected for its overlap with the 2, 1 - inserted methyl signal. Then, according to the following formula, the percentage of the m_m pentad %mmmm = ARE Ammnim / (AREABniBID + AREAmmmr + AREA··· + ARE Amrrm ) ' 1 0 Percentage of the 2,1 -insert of the propylene metal propylene homopolymer Determination: The signal corresponding to 2, Bu insertion was determined by means of published information (for example, HN Cheng, j. Ewen, Makr* 〇m〇h Cherny 190 (1989), pages 1931-1940). The first area AREA1 is defined as the average area of the signal corresponding to the 2, 1-insertion. The second area AREA2 is defined as the average area of the signal corresponding to the 丨, 2- insertion. The identification of signals associated with 1,2-insertion is well known to the skilled person 29 201245519 and does not require further explanation. 2, 1-insert percentage is calculated according to the following formula: 2, insert (%) = AREAU (AREA1 + AREA2) · 100 where '2, 1-% of the insert is as 2, 1_ inserted propylene relative to all propylene The mole percentage is given. The determination of the percentage of the intercalation of the metallocene random copolymer of propylene and ethylene is determined by the following two contributions: (i) the percentage of 2,1-insertion as defined above for the propylene homopolymer, and (ii) Where 2, 1-inserted propylene is adjacent to ethylene, 2 is the percentage of insertion, so the total percentage of '2, 1-insertion corresponds to the sum of these two contributions. The identification of the signal of the case (i i) is carried out by using a reference spectrum or by referring to published literature. The melting temperature T was measured on a TA Instruments DSC Q2000 instrument according to I SO 3146. To eliminate the thermal history, the sample was first heated to 200 C ' and held at 2 ° C for 3 minutes. The reported melting temperature T* is then determined using 2 (heating and cooling rate of TC/min'. Fiber tenacity and elongation are measured on a Lenzing Vibrodyn according to ISO 5079:1995 with a test speed of 1 〇mm/miη. Tensile strength and elongation of the article are measured according to ISO 9073-3:1989. EXAMPLES In order to illustrate the advantages of the present invention, two polypropylene compositions (referred to as 201245519 • ΤΝ ΤΝ Τ > ν ^ yy and ΡΡ 2 ) are different. Use under fiber spinning conditions - Polypropylene composition ρρι consists of a propylene homopolymer: the above propylene sentence polymer is used in industrial scale polymerization equipment with dimethyl decyl bridged bis(knot) Gasoline-based metallocene-based polymerization catalysts as metallocene components are produced under standard polymerization conditions. The polypropylene composition PP2 is composed of a propylene homopolymer: the above-mentioned propylene homopolymer is used in industrial scale polymerization equipment. The Gele-Natta polymerization catalyst is produced under standard polymerization conditions, followed by #cracking to increase the refining flow index and narrowing the molecular weight distribution. The corresponding polypropylene used in PP1 and PP2 ( The properties of sufficient antioxidants and acid scavengers to reduce their degradation during processing are given in Table I.

Table I ΡΡΙ PP2 — (Comparative) MFI dg/min 24.9 25.1 Μ*/Μ„ (via GPC) 2.8 4.1 T-column (via DSC): C 152 163 2, 1-insert (by NMR) % 0.8 Undetectable spinning Viscous nonwovens Polypropylene compositions PP and PP2 were used to make spun nonwovens on a 1-1111 wide Reicofil 4 line with a single beam having about 6800 holes per meter length, the holes having a crucible. A diameter of 6 mm. The target fabric weighs 12 g/m2. The above nonwovens are thermally bonded using an embossing roll (einb〇ssed r〇u) 31 201245519. Other processing conditions are given in Table 11. In Table 11 The temperature of the molten polypropylene stream is expressed as "die-melt temperature." The calender temperature in Table II (expressed as "calender temperature") is the bonding temperature at which the temperature is obtained. The highest value of the maximum tensile strength. The calender temperature was measured on the embossing roll using a contact thermocouple. The properties of the obtained nonwoven are shown in Table 111, where MD stands for "longitudinal" and CD stands for "lateral".

Table II Example 1 Example 2 (Comparative) Example 3 (Comparative) Example 4 (Comparative) Polypropylene composition PP1 PP1 PP2 PP2 Production line output kg/h 181 181 181 181 Yield per well g/孑L/ Min 0.41 0.41 0.41 0.42 Line speed m/min 232 228 235 225 Die melt temperature °C 271 249 268 250 Melt pressure bar 47 59 42 Cannot get H (cabin) pressure Pa 8000 7800 4000 6000 Calender temperature °C 136 142 wood) 147 *) indicates that a nonwoven fabric cannot be produced due to unstable spinning.

Table III Example 1 Example 2 (Comparative) Example 3 (Comparative) Example 4 (Comparative) Fiber Denier 0.84 0.95 1.27 1.0 Fabric Weight (measured value) g/m2 11.8 12.8 *) Tensile Strength @ Max 32 201245519 Elongation MD N/5cm 44.8 41.0 CD N/5cm 22.8 21 〇MD °/o 70 60 CD °/〇75 ------1 L62 Wood) indicates that it is impossible to manufacture non-woven wood due to unstable spinning *) wood) wood) 34.8 17.9 63 67 The results show that the increase in melt temperature (ie the temperature of the molten polypropylene stream) leads to the "fine temperature extrusion" of the final fineness of the fiber, which is reduced by more than m'. It is seen from the results of Example i and Example 2. Interestingly and also very surprisingly, it is possible to reduce the final fiber titer by increasing the temperature of the solution only for the composition comprising the gold (4) (iv). The polypropylene composition (see Example 3) operated under "high temperature conditions" could not be processed into a nonwoven due to unstable spinning. It was further surprisingly found that "the improved tensile strength and the improved CD direction have improved stretch. High temperature extrusion conditions, 'allows the manufacture of nonwovens with elongation, as well as in MD and strength and S high Non-woven fabric with a low rate [Simple description of the drawing] No [Main component symbol description] 33

Claims (1)

201245519 VII. Patent application scope: 1. A method for manufacturing fine polypropylene fibers and a nonwoven fabric comprising the above-mentioned fine polypropylene fibers, wherein the fine polypropylene fibers are characterized by a maximum of 1, 2, and a fineness, and the above method comprises the following steps: . (4) providing the polypropylene composition to an extruder, the above-mentioned polyphobic person comprising a metallocene polypropylene having a total weight of at least 5 Å relative to the upper 4 ° ° π π upper propylene composition, 0 (b) Subsequent melt extruding the above polypropylene composition to obtain a molten polypropylene stream; () extruding the above molten polypropylene stream of step (b) from a plurality of fine, generally® shaped capillaries of the die, Thereby obtaining (four) filaments of the polymer; and (d) subsequently cooling the filament obtained in the step ((:) and reducing its fineness to the final fiber titer, wherein in the step (c), the melting The temperature of the polypropylene stream is at least T«ak + ll〇C, wherein TRai is the melting temperature of the above metallocene polypropylene determined according to IS03146. 2. The method of claim ii, further comprising the following steps (e) collecting the above-mentioned filaments obtained in the step (d) on a carrier; and (〇 subsequently combining the collected filaments of the step (e) to form a bonded nonwoven. The method of item 1 or 2, wherein, in step (c), the temperature of said molten polymer stream is at least T «« + 120 ° C, wherein 34 201245519 is the metallocene polypropylene obtained in step (a) The method of any one of the preceding claims, wherein the pentametal polypropylene is a copolymer of propylene and at least one comonomer, the at least one comonomer and The propylene monomer is different from the total weight of the metallocene propylene polymer, and the comonomer content of the above i to the above-mentioned comonomer is at most 2. 〇% by weight ^ j The method of any of the preceding claims, wherein: the metallocene polypropylene has a melt maneuver of at least 1 〇dg/min and a maximum of 15 _ _ _ MFI 'the above melt flow finger 娄 quot η according to Is 1133, condition L, measured at 23 〇t and 2 16 kg. The method of any of the preceding claims, wherein the above metallocene polypropylene has a melting temperature of up to 16 Å as determined according to ISO 3146. 7. The method of any one of claims 196 Wherein the above method is characterized in that the final fineness of the fiber thus produced is at most 95% of the final fineness of the fiber produced under the same conditions but at a temperature of at most T^ + 1 () (rc) melt polymer stream, wherein T "For the melting temperature of the above metallocene polypropylene determined according to IS0 3146. 8. The method of any one of claims 1 to 7, wherein the above-mentioned square= is characterized in that in the step (c), the 'die pressure is under the same condition but 疋 is at most T +1 1 〇 (Up to 80% of the die pressure at the molten polymer stream temperature of rc, 35 201245519 where TU is the melting temperature of the above metallocene polypropylene as determined according to ISO 3146. 9. As claimed in paragraphs i to 8 of the patent application scope The method of the above-mentioned method is characterized in that the elongation of the nonwoven determined according to IS0 9073_3:1 989 is at least 105% of the elongation of the nonwoven having substantially the same weight per unit surface, the latter The spun is produced under the same conditions but at the highest temperature of the molten polymer stream, wherein T*» is the melting temperature of the above metallocene polypropylene determined according to ISO 3146. 10. As claimed in claims i to 9 A method, wherein the above method is characterized in that the tensile strength of the nonwoven described in I according to ISO 9073_3:1 989 is at least 104% of the tensile strength of the nonwoven having substantially the same basis weight, Preferably at least 106%, the post-nonwovens are produced under the same conditions but at a temperature of up to Tu + lOOt of molten polymer stream, 4Μ', where Τ«« is the melting temperature of the above metallocene polypropylene determined according to ISO 3146 11. The method of any one of claims 1 to 10 wherein the method is characterized by a bonding temperature temperature of the molten polymer stream at a temperature greater than τ «tt+i〇〇t: The drying temperature of the polypropylene fiber obtained below is at least 2 ° C lower, wherein the melting temperature of the above metallocene polypropylene is determined according to ISO 3146. 12. The method according to any one of claims 6 to 6 Manufacture 36 201245519 Use in a fine polypropylene fiber comprising at least 50% by weight of a metallocene polypropylene-fired polypropylene composition, characterized in that the final fineness of the fiber thus produced is under the same conditions but S is at most T "+ 1 GGt of the final fineness of the fibers produced at a molten polymer stream temperature of up to 95%, or characterized by: in step (e), the die pressure is under the same conditions but at Up to (10).c(iv) melt polymerization (iv) at flow temperature (iv) up to 80% of head pressure, or characterized by: the elongation of the nonwoven determined according to Is〇9G73_3:1 989 is a nonwoven having substantially the same weight per unit surface At least 1 〇 5% of the length = the length of the nonwoven is produced under the same conditions but at a temperature of the molten polymer stream of at most T«« + i〇〇t: or characterized in that: according to lso The tensile strength of the above-mentioned nonwoven material determined by 9〇73_3:1 989 is at least a touch, preferably at least _, of the tensile strength of the nonwoven having substantially the same basis weight, and the post-nonwoven under the same conditions But at most τ "+(10). (iii) Manufactured at the temperature of the molten polymer stream, or characterized in that the bonding temperature is higher than that of the polypropylene fiber obtained under the same conditions but at a maximum of Τ«« + 1 〇(Γ(: molten polymer stream temperature) The combined temperature is at least 2 ° C, wherein is the melting temperature of the above metallocene polypropylene determined according to ISO 3146. 13. A polypropylene fiber composed of a polypropylene composition comprising the above polypropylene The total weight of the composition is at least 5〇37 201245519% by weight of the metallocene propylene polymer, which is substantially circular and has a titre of up to 1.2 denier.