WO2018030057A1 - Nonwoven fabric and method for manufacturing same - Google Patents

Nonwoven fabric and method for manufacturing same Download PDF

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Publication number
WO2018030057A1
WO2018030057A1 PCT/JP2017/025233 JP2017025233W WO2018030057A1 WO 2018030057 A1 WO2018030057 A1 WO 2018030057A1 JP 2017025233 W JP2017025233 W JP 2017025233W WO 2018030057 A1 WO2018030057 A1 WO 2018030057A1
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Prior art keywords
nonwoven fabric
fibers
fiber diameter
less
average
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PCT/JP2017/025233
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French (fr)
Japanese (ja)
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正士 伊藤
祐一 武田
平原　武彦
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東レ・ファインケミカル株式会社
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Priority to JP2018532881A priority Critical patent/JP6957472B2/en
Publication of WO2018030057A1 publication Critical patent/WO2018030057A1/en

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    • 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
    • D04H3/02—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments
    • D04H3/03—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments at random
    • D04H3/033—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of forming fleeces or layers, e.g. reorientation of yarns or filaments at random reorientation immediately after yarn or filament formation

Definitions

  • the present invention relates to a nonwoven fabric and a method for producing the same.
  • non-woven fabrics made of ultrafine fibers have been used for various types of filters and the like, and non-woven fabrics formed with fibers having a small fiber diameter are excellent in capturing fine particles, and thus are applied to liquid filters, air filters, etc. ing.
  • a melt blown nonwoven fabric produced by spinning a molten thermoplastic resin has been studied for forming a nonwoven fabric with fibers having a small fiber diameter.
  • a filter excellent in high collection efficiency has been proposed by producing nonwoven fabrics having two different fiber diameters by a melt blow method (see, for example, Patent Document 1).
  • a non-woven fabric having an average fiber diameter of 1 ⁇ m or less has been proposed as a melt blown nonwoven fabric made of ultrafine fibers, but the strength is very weak because of the large volume ratio of fine fibers.
  • Patent Document 4 Although there is a disclosure of a nonwoven fabric having a higher specific surface area, the presence of many fine fibers increases the specific surface area, but the amount of interfiber fusion decreases accordingly, so that only low strength can be obtained. (For example, refer to Patent Document 5).
  • the present invention solves the above-mentioned problems, and provides a nonwoven fabric excellent in strength when processing sheets while having ultrafine fibers and a method for producing the same.
  • the nonwoven fabric of the present invention has an average fiber diameter of 0.8 ⁇ m or less, and a volume ratio of fibers having a fiber diameter of 1.0 ⁇ m or less is less than 40%. .
  • the average basis weight is preferably 10 g / m 2 or more.
  • the stress at 5% elongation in the longitudinal direction is preferably 5.0 N / 5 cm or more.
  • the resin discharge amount per spinning nozzle is set to 0.01 g / min or more, and the die temperature is set so that the polymer pressure of the die portion is 2.3 MPa or more.
  • the present invention it is possible to provide a nonwoven fabric that has ultrafine fibers and is excellent in strength during sheet processing, and a method for producing the same.
  • FIG. 1 is a histogram of fiber diameter distribution in the nonwoven fabrics of Examples and Comparative Examples. 1A shows the fiber diameter distribution in each of the nonwoven fabrics of Example 1, FIG. 1B shows the Example 2 and FIG. 1C shows the Comparative Example 1.
  • FIG. 2 is an SS curve in the tensile test.
  • the nonwoven fabric of the present invention has an average fiber diameter of 0.8 ⁇ m or less, and further, the ratio of fibers having a fiber diameter of 1.0 ⁇ m or less is less than 40% in terms of volume.
  • the nonwoven fabric excellent in the intensity
  • the nonwoven fabric of the present invention is characterized in that the average fiber diameter of fibers constituting the nonwoven fabric is 0.8 ⁇ m or less, and the volume ratio of fibers having a fiber diameter of 1.0 ⁇ m or less is less than 40%.
  • the average fiber diameter is preferably 0.7 ⁇ m or less, and more preferably 0.4 ⁇ m or less.
  • the lower limit value of the average fiber diameter is preferably 0.1 ⁇ m or more.
  • the ratio of the fibers of 1.0 ⁇ m or less is preferably 10% or more and less than 40%, more preferably 20% or more and 35% or less by volume ratio.
  • the volume ratio of the fibers of 1.0 ⁇ m or less is 40% or more, the strength of the sheet is lowered, and when the filter is processed, the sheet is stretched and deformed or easily broken during processing. If it is less than 10%, since there are many thick fibers, the fine pore size of the nonwoven fabric increases, so fine dust particles may not be captured, and the function as a filter tends to be insufficient. .
  • the average fiber diameter is a value calculated from a specific fiber diameter per 200 fibers constituting the nonwoven fabric, as shown in the fiber diameter measurement method described later, and a volume ratio (ratio in terms of volume) and Is a value calculated based on numerical values obtained from fiber diameter measurement, which will be described later.
  • Nonwoven fabric of the present invention has an apparent density of the 0.05 g / cm 3 or more 0.50 g / cm 3 or less, and the maximum pore diameter is preferably not more than 10.0 [mu] m.
  • the apparent density is more preferably 0.08 g / cm 3 or more and 0.30 g / cm 3 or less. More preferably, it is 0.11 g / cm 3 or more and 0.15 g / cm 3 or less.
  • the nonwoven fabric may be laminated, calendered, or adjusted as appropriate, but a single-layer nonwoven fabric is more preferable in terms of handleability and cost.
  • the apparent density is a value obtained by measuring the average thickness and the average basis weight of the nonwoven fabric as described later and calculating by the following formula. It can be said that the smaller the apparent density, the bulkier the nonwoven fabric.
  • Apparent density (g / cm 3 ) ⁇ average basis weight (g / m 2 ) / average thickness (mm) ⁇ / 1000
  • the average basis weight is preferably 10 g / m 2 or more as the basis weight increases as the basis weight increases in consideration of workability in the next step in handling the nonwoven fabric. Furthermore, as described above, it is more preferable in terms of handleability and cost to obtain a nonwoven fabric having a single layer and an average basis weight of 10 g / m 2 or more.
  • the fibers constituting the nonwoven fabric of the present invention are made of a thermoplastic resin. If it is a thermoplastic resin, it will not specifically limit, Polyester, polyolefin, polyamide, polyphenylene sulfide, etc. can be used. Of these, polypropylene microfibers are preferred. Although a well-known thing can be used for a polypropylene resin, when manufacturing by the melt blow method mentioned later, it is preferable that MFR (melt flow rate) exists in the range of 10 g / 10min or more and 2000 g / 10min or less. The MFR indicating the physical property value of the resin is measured by a standard test method of JIS K7210-1. For the polypropylene resin, it is a value measured under measurement conditions of 2.16 kg and 230 ° C. (conditions determined for polypropylene resin in JIS K6921-2).
  • the nonwoven fabric is preferably a melt blown nonwoven fabric.
  • a compressed gas for example, air
  • the melt-blowing method is preferable because a nonwoven fabric having an average fiber diameter including ultrafine fibers of 0.80 ⁇ m or less can be easily obtained.
  • the non-woven fabric production method of the present invention is characterized in that, in the melt-blowing method, the resin discharge amount per spinning nozzle is 0.01 g / min or more and the die pressure is 2.3 MPa or more.
  • the die pressure is less than 2.3 MPa, the straightness of the polymer spun from the die is lost and the spinning becomes unstable, so that it becomes a block polymer called a shot and is sprayed onto the nonwoven fabric.
  • the upper limit value of the die pressure is about 10 MPa. However, this is a standard restriction on the current apparatus, and therefore the upper limit value is not limited to this upper limit as long as the restriction is eliminated.
  • the resin discharge rate per spinning nozzle is 0.01 g / min or more. It is necessary. If the resin discharge rate is less than 0.01 g / min, more fine fibers having a fiber diameter of, for example, 1.0 ⁇ m or less can be spun, but the ratio of the fine fibers becomes too large. Therefore, the fusion between the fibers is weakened, the strength of the sheet cannot be maintained, and the sheet is stretched or broken during the process.
  • the suction equipment for collecting the fibers after the injection of the die into a sheet shape fine fibers called blown cotton are generated without collecting the fine fibers.
  • the resin discharge rate is 0.01 g / min or more, for example, some thick fibers having a fiber diameter exceeding 1.0 ⁇ m are present. By this thick fiber, the inter-fiber fusion of the nonwoven fabric becomes strong, and a high-strength sheet is obtained. Furthermore, since the thick fibers entangle the thin fibers, the occurrence of fluff can be suppressed and the basis weight can be increased.
  • the resin discharge rate is preferably 0.2 g / min or less. If the resin discharge amount is too large, the proportion of thick fibers increases too much, which is not preferable.
  • a raw material resin having an MFR indicating a physical property value of the resin in a range of 10 g / 10 min to 2000 g / 10 min.
  • the measurement temperature of the MFR indicating the physical property value of the resin is regulated according to the type of the resin. For example, the measurement temperature is 230 ° C. for polypropylene. Since the die temperature is generally set to a temperature in the vicinity of the MFR measurement temperature indicating the physical property value of the resin, in order to produce a desired nonwoven fabric, it is necessary to select a resin having an MFR within a predetermined range. It is preferable to use it as an index.
  • a nonwoven fabric as defined above can be suitably obtained.
  • Example 1 Using a melt blown nonwoven fabric manufacturing apparatus, a nonwoven fabric was manufactured using polypropylene resin as a raw material.
  • the polypropylene resin was used, and the set temperature of the die was 260 ° C. and the discharge rate per spinning nozzle hole having a diameter of 0.12 mm was 0.017 g / min in the manufacturing apparatus. From both sides of the spinning nozzle, air heated and compressed at a set temperature of 290 ° C.
  • a nonwoven fabric was obtained in the same manner as in Example 1 except that the set temperature of the die was 240 ° C and the set temperature of the heated and compressed air was 230 ° C. The die pressure at this time was 2.9 MPa.
  • the physical properties of the obtained nonwoven fabric were measured by the methods described below. The results are shown in Table 1.
  • a histogram of the fiber diameter distribution of the obtained nonwoven fabric is shown in FIG. 1B, and an SS curve in a tensile test for one test piece is shown by a broken line in FIG.
  • Example 1 A nonwoven fabric was obtained in the same manner as in Example 2, except that the discharge amount per hole of the spinning nozzle was 0.008 g / min and the set temperature of the heated and compressed air was 190 ° C. The die pressure at this time was 2.6 MPa. The physical properties of the obtained nonwoven fabric were measured by the methods described below. The results are shown in Table 1. In addition, a histogram of the fiber diameter distribution of the obtained nonwoven fabric is shown in FIG. 1 (c), and an SS curve in a tensile test for one test piece is shown by a one-dot chain line in FIG.
  • Example 2 A nonwoven fabric was obtained in the same manner as in Example 2, except that the discharge amount per hole of the spinning nozzle was 0.008 g / min, and the set temperature of the heated and compressed air was 290 ° C. The die pressure at this time was 2.0 MPa. Under these conditions, shots occurred frequently, and a uniform sheet could not be obtained. This is because the die pressure was lowered and the spinnability deteriorated.
  • the nonwoven fabric of Example 1 had an average fiber diameter of 0.61 ⁇ m and a fiber volume ratio of 1.0 ⁇ m or less of 25.2%.
  • the tensile strength was 21.4 N / 5 cm, and the stress at 5% elongation was as high as 18.3 N / 5 cm.
  • a nonwoven fabric containing ultrafine fibers and having excellent process passability was obtained.
  • the nonwoven fabric of Example 2 had an average fiber diameter of 0.68 ⁇ m and a fiber volume ratio of 1.0 ⁇ m or less was 24.3%.
  • the tensile strength was 19.1 N / 5 cm, and the stress at 5% elongation was as very high as 15.4 N / 5 cm.
  • a nonwoven fabric containing ultrafine fibers and having excellent process passability was obtained.
  • the nonwoven fabric of Comparative Example 1 had an average fiber diameter of 0.63 ⁇ m, but the volume ratio of fibers of 1.0 ⁇ m or less was 40.0%.
  • the tensile strength was 7.1 N / 5 cm, and the stress at 5% elongation was as low as 1.1 N / 5 cm. Since there are few thick fibers, high strength could not be obtained, and although the sheet contained ultrafine fibers, the sheet broke during the process.
  • the average thickness is obtained by cutting the obtained non-woven fabric into 250 mm ⁇ 250 mm, measuring the central part of each side with a dial thickness gauge, calculating the average value from the obtained values, and placing the third decimal place Was calculated by rounding off.
  • the average basis weight is obtained by collecting three test pieces obtained by cutting the obtained nonwoven fabric into 250 mm ⁇ 250 mm, measuring each mass with an electronic balance, calculating the average value of the three pieces, and multiplying the average value by 16 Calculated by rounding off the second decimal place.
  • the average fiber diameter, the fiber number ratio, and the fiber volume ratio were determined by measuring the fiber diameter from a photograph of the obtained nonwoven fabric taken at 5000 times with an electron microscope.
  • the average fiber diameter was determined by arbitrarily measuring the fiber diameter from 10 photos to 200 ⁇ m diameter on the order of 0.01 ⁇ m, averaging them, and rounding off to the third decimal place.
  • the number ratio of fibers having a fiber diameter of 1.0 ⁇ m or less was expressed as a percentage by dividing the number of fibers having a fiber diameter of 1.0 ⁇ m or less out of the 200 fibers by the total number of measured fibers.
  • the volume ratio of the fibers having a fiber diameter of 1.0 ⁇ m or less is the sum of values obtained by squaring the fiber diameters for the fibers having a diameter of 1.0 ⁇ m or less among the 200 fibers, and the fiber diameters for all the measured fibers. Divided by the sum of the squared values and rounded off to one decimal place.
  • Dw / Dn is an index representing the fiber diameter distribution calculated based on these, and the closer to 1, the more uniform the fiber diameter distribution.
  • a non-woven fabric test piece impregnated with the reagent is set in a holder of the measuring instrument and measured.
  • d Cr / P (Formula 1)
  • d maximum pore diameter ( ⁇ m)
  • r surface tension of reagent (15.9 mN / m)
  • P differential pressure (Pa)
  • C pressure constant (2860)
  • a test piece of dry nonwoven fabric is set in the automatic pore size distribution measuring instrument, and the air pressure applied to one surface is gradually increased to show the relationship between the pressure and the flow rate when air passes through the dry test piece.
  • a dry flow curve (DRY FLOW CURVE) was measured. At this time, let P1 be the pressure when the air begins to permeate the dry test piece. Next, based on the dry flow rate curve, a half dry flow rate curve with a permeate flow rate of 1/2 was created. And after the said test piece was immersed in the said reagent, the same measurement was performed and the wetting flow rate curve (WET FLOW CURVE) was obtained.
  • the average pore diameter d m is the pressure P 2 in the intersection of the half-dry flow curve and wet flow curve, from the differential pressure P c of the P 1, is calculated using the following equation 2, the second decimal place Rounded off.
  • d m Cr / P c (Formula 2)
  • d m average pore diameter ( ⁇ m)
  • r surface tension of liquid (15.9 mN / m)
  • P c differential pressure (P 2 ⁇ P 1 ) (Pa)
  • C pressure constant (2860)
  • the non-woven fabric of the present invention is excellent in uniformity while containing thick fibers at a certain ratio or more, and since it contains ultrafine fibers and has high strength, it can be suitably used for various filter applications, particularly for liquid filter applications. It can be used suitably. Moreover, according to the method for producing a nonwoven fabric of the present invention, it is possible to produce a nonwoven fabric that is excellent in uniformity, contains ultrafine fibers, and has high strength.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Nonwoven Fabrics (AREA)
  • Filtering Materials (AREA)
  • Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

Abstract

Provided is a nonwoven fabric having ultrafine fibers and excellent strength during sheet working, and a method for manufacturing the same. This nonwoven fabric is characterized in that the average fiber diameter is 0.8 μｍ or less, and the volume ratio of fibers having a fiber diameter of 1.0 μｍ or less is less than 40%. This method for manufacturing nonwoven fabric is a melt-blowing method characterized in that the die temperature is set such that the resin ejection amount per spinning nozzle is 0.01 g/min or higher and the polymer pressure on the die is 2.3 MPa or higher.

Description

不織布およびその製造方法Nonwoven fabric and method for producing the same
　本発明は、不織布およびその製造方法に関する。 The present invention relates to a nonwoven fabric and a method for producing the same.
　従来、極細繊維からなる不織布は、各種フィルター等に用いられており、繊維径の小さい繊維で形成された不織布は、微粒子の捕捉性に優れていることから、液体フィルター、エアフィルター等に適用されている。特に、溶融した熱可塑性樹脂を紡糸して製造するメルトブロー不織布については、繊維径の小さい繊維で不織布を形成するための検討がなされている。例えば、メルトブロー法にて、異なる２種類の繊維径を有する不織布を製造することで、高捕集効率に優れるフィルターが提案されている（例えば、特許文献１参照）。この場合、７０μｍ以上の太い繊維を有するため、液体フィルターのように、緻密な粒子を均一に濾過しようとする場合、太い繊維による空隙が発生し、漏れの原因となるため好ましくない。また、エレクトロスピニングを用いた溶液紡糸との組み合わせによって２種類の繊維を混繊させた不織布についての記載があるが、細繊維の体積比率が少なく、濾過精度に劣るものであった（例えば、特許文献２参照）。同じく、エレクトロスピニングを用いた溶液紡糸との組み合わせによって２種類の繊維を混繊させた不織布についての記載があるが、繊維径差が大きく、さらに細繊維の体積比率が少なくなるため、好ましくない（例えば、特許文献３参照）。 Conventionally, non-woven fabrics made of ultrafine fibers have been used for various types of filters and the like, and non-woven fabrics formed with fibers having a small fiber diameter are excellent in capturing fine particles, and thus are applied to liquid filters, air filters, etc. ing. In particular, a melt blown nonwoven fabric produced by spinning a molten thermoplastic resin has been studied for forming a nonwoven fabric with fibers having a small fiber diameter. For example, a filter excellent in high collection efficiency has been proposed by producing nonwoven fabrics having two different fiber diameters by a melt blow method (see, for example, Patent Document 1). In this case, since it has a thick fiber of 70 μm or more, when trying to filter dense particles uniformly as in a liquid filter, voids due to the thick fiber are generated, which causes leakage, which is not preferable. In addition, there is a description of a nonwoven fabric in which two types of fibers are mixed by combination with solution spinning using electrospinning, but the volume ratio of fine fibers is small and the filtration accuracy is poor (for example, patents). Reference 2). Similarly, although there is a description of a nonwoven fabric in which two types of fibers are mixed by combination with solution spinning using electrospinning, it is not preferable because the fiber diameter difference is large and the volume ratio of fine fibers is reduced ( For example, see Patent Document 3).
　極細繊維からなるメルトブロー不織布として、平均繊維径１μｍ以下からなる不織布が提案されているが、細繊維の体積比率が多いため、強度は非常に弱いものである。積層によって強度向上の開示もあるが、積層枚数が多いと、積層間での剥離が発生し、フィルターとして使用するには好ましくない（例えば、特許文献４参照）。さらに高い比表面積を有する不織布についての開示があるが、細繊維が多く存在することで、比表面積が多くなるが、その分、繊維間融着が少なくなるため、強度の低いものしか得られない（例えば、特許文献５参照）。融着の少ない極細不織布についての開示があるが、融着が少ないと強度の低いシートしか得られないため、工程通過時に、破れが発生する等、好ましくない（例えば、特許文献６参照）。不織布の孔径分布の狭い不織布について開示があるが、分布が狭い場合、細い繊維のみとなりやすく、程好く太い繊維が存在しないと、強度に劣るものとなってしまし好ましくない（例えば、特許文献７参照）。 A non-woven fabric having an average fiber diameter of 1 μm or less has been proposed as a melt blown nonwoven fabric made of ultrafine fibers, but the strength is very weak because of the large volume ratio of fine fibers. There is also a disclosure of strength improvement by lamination, but if the number of laminated layers is large, peeling occurs between the laminated layers, which is not preferable for use as a filter (see, for example, Patent Document 4). Although there is a disclosure of a nonwoven fabric having a higher specific surface area, the presence of many fine fibers increases the specific surface area, but the amount of interfiber fusion decreases accordingly, so that only low strength can be obtained. (For example, refer to Patent Document 5). Although there is disclosure of an ultra-fine nonwoven fabric with little fusion, it is not preferable that only a low-strength sheet can be obtained if there is little fusion, such as tearing when passing through the process (see, for example, Patent Document 6). Non-woven fabrics with a narrow pore size distribution are disclosed, but if the distribution is narrow, only thin fibers are likely to be obtained, and if there are no reasonably thick fibers, the strength is inferior (eg, patent documents). 7).
　さらに、高電圧の印加によって融着を促進させる製法についての記載があるが、印加による融着では、強度向上に十分な影響を与えることはできない。また、口金噴射直下にそのような設備を設置することで、気流の乱れによりシートに筋が発生することも考えられる（例えば、特許文献８参照）。 Furthermore, although there is a description of a production method that promotes fusion by applying a high voltage, fusion by application cannot sufficiently affect strength improvement. In addition, it is also conceivable that a streak is generated in the sheet due to the turbulence of the air flow by installing such equipment directly under the nozzle injection (see, for example, Patent Document 8).
特開２０１５－１９６９２０号公報JP-A-2015-196920 特開２０１０－１８５１５４号公報JP 2010-185154 A 特開２００９－０５７６５５号公報JP 2009-057655 A 特開２０１６－０５３２４１号公報JP 2016-053241 A 特開２０１５－１９００８１号公報Japanese Patent Laid-Open No. 2015-190081 特開２０１５－０９２０３８号公報Japanese Patent Laying-Open No. 2015-092038 特開２０１６－０３０８６６号公報JP 2016-030866 A 国際公開第２０１２／０１４５０１号International Publication No. 2012/014501
　極細メルトブロー不織布においては、平均繊維径を小さくすることが重要であり、その方法について、様々な検討がなされてきた。ただし、細い繊維が得られたとしても、目付が低いものであったり、シートの強度が低い場合は、メルトブロー不織布を様々な用途へ加工することが困難となる。シートの強度を向上させるためには、他素材を積層させる等の方法が挙げられるが、積層間での剥がれや、接着による濾過面積の減少等があり、フィルターとして十分な性能が得られなかった。 In ultrafine melt blown nonwoven fabrics, it is important to reduce the average fiber diameter, and various studies have been made on the method. However, even if fine fibers are obtained, if the basis weight is low or the strength of the sheet is low, it is difficult to process the melt-blown nonwoven fabric for various uses. In order to improve the strength of the sheet, there are methods such as laminating other materials, but there was peeling between the layers, reduction of the filtration area due to adhesion, etc., and sufficient performance as a filter could not be obtained .
　本発明は上記課題を解決するものであり、極細繊維を有しながら、なおかつシートを加工する際の強度に優れた不織布およびその製造方法を提供するものである。 The present invention solves the above-mentioned problems, and provides a nonwoven fabric excellent in strength when processing sheets while having ultrafine fibers and a method for producing the same.
　前記目的を達成するために、本発明の不織布は、平均繊維径が０．８μｍ以下であり、かつ、繊維径が１．０μｍ以下の繊維の体積比率が４０％未満であることを特徴とする。 In order to achieve the above object, the nonwoven fabric of the present invention has an average fiber diameter of 0.8 μm or less, and a volume ratio of fibers having a fiber diameter of 1.0 μm or less is less than 40%. .
　本発明の不織布において、平均目付が１０ｇ／ｍ２以上であることが好ましい。 In the nonwoven fabric of the present invention, the average basis weight is preferably 10 g / m 2 or more.
　本発明の不織布において、長手方向の５％伸張時応力が、５．０Ｎ／５ｃｍ以上であることが好ましい。 In the nonwoven fabric of the present invention, the stress at 5% elongation in the longitudinal direction is preferably 5.0 N / 5 cm or more.
　本発明の不織布の製造方法は、メルトブロー法において、紡糸ノズル当たりの樹脂吐出量を０．０１ｇ／分以上とし、ダイ部分のポリマー圧力が２．３ＭＰａ以上となるようにダイ温度を設定することを特徴とする。 In the method for producing a nonwoven fabric of the present invention, in the melt blowing method, the resin discharge amount per spinning nozzle is set to 0.01 g / min or more, and the die temperature is set so that the polymer pressure of the die portion is 2.3 MPa or more. Features.
　本発明によれば、極細繊維を有しながら、なおかつシート加工時の強度に優れる不織布およびその製造方法を提供することができる。 According to the present invention, it is possible to provide a nonwoven fabric that has ultrafine fibers and is excellent in strength during sheet processing, and a method for producing the same.
図１は、実施例および比較例の不織布における繊維径分布のヒストグラムである。図１（ａ）は実施例１、図１（ｂ）は実施例２、図１（ｃ）は比較例１のそれぞれの不織布における繊維径分布である。FIG. 1 is a histogram of fiber diameter distribution in the nonwoven fabrics of Examples and Comparative Examples. 1A shows the fiber diameter distribution in each of the nonwoven fabrics of Example 1, FIG. 1B shows the Example 2 and FIG. 1C shows the Comparative Example 1. 図２は、引張試験におけるＳ－Ｓカーブである。FIG. 2 is an SS curve in the tensile test.
　以下、本発明をさらに具体的に述べる。本発明の不織布は、平均繊維径が０．８μｍ以下であり、さらに繊維径が１．０μｍ以下の繊維の割合を体積換算にて４０％未満とすることにより、濾過精度に優れ、なおかつ、工程通過性に必要となる強度に優れる不織布とその製造方法を実現することができたものである。 Hereinafter, the present invention will be described more specifically. The nonwoven fabric of the present invention has an average fiber diameter of 0.8 μm or less, and further, the ratio of fibers having a fiber diameter of 1.0 μm or less is less than 40% in terms of volume. The nonwoven fabric excellent in the intensity | strength required for permeability and its manufacturing method were able to be implement | achieved.
　本発明の不織布は、不織布を構成する繊維の平均繊維径が０．８μｍ以下であり、さらに繊維径が１．０μｍ以下の繊維の体積比率が４０％未満であることを特徴とする。平均繊維径は、好ましくは、０．７μｍ以下であり、より好ましくは０．４μｍ以下である。平均繊維径の下限値は０．１μｍ以上であることが好ましい。平均繊維径が０．８μｍを超えると、不織布の細孔径が大きくなるために細かい粒子径のダストを捕捉することができない場合があり、フィルターとしての機能が不十分なものとなりやすい。また、１．０μｍ以下の繊維の割合は、好ましくは体積比率で１０％以上４０％未満、より好ましくは２０％以上３５％以下である。１．０μｍ以下の繊維の体積比率が４０％以上であると、シートの強度が低下し、フィルターを加工する際、シートが伸びて変形したり、加工中に破断しやすくなる。１０％よりも少なくなると、太い繊維が多く存在するため、不織布の細孔径が大きくなるために細かい粒子径のダストを捕捉することができない場合があり、フィルターとしての機能が不十分なものとなりやすい。ここで平均繊維径とは、後述する繊維径の測定方法において示すように、不織布を構成する繊維２００本当たりの特定の繊維径から算出した値であり、体積比率（体積換算での比率）とは、同じく後述する繊維径測定から得られた数値を元に算出した値である。 The nonwoven fabric of the present invention is characterized in that the average fiber diameter of fibers constituting the nonwoven fabric is 0.8 μm or less, and the volume ratio of fibers having a fiber diameter of 1.0 μm or less is less than 40%. The average fiber diameter is preferably 0.7 μm or less, and more preferably 0.4 μm or less. The lower limit value of the average fiber diameter is preferably 0.1 μm or more. When the average fiber diameter exceeds 0.8 μm, the fine pore diameter of the nonwoven fabric increases, so that dust with a fine particle diameter may not be captured, and the function as a filter tends to be insufficient. Further, the ratio of the fibers of 1.0 μm or less is preferably 10% or more and less than 40%, more preferably 20% or more and 35% or less by volume ratio. When the volume ratio of the fibers of 1.0 μm or less is 40% or more, the strength of the sheet is lowered, and when the filter is processed, the sheet is stretched and deformed or easily broken during processing. If it is less than 10%, since there are many thick fibers, the fine pore size of the nonwoven fabric increases, so fine dust particles may not be captured, and the function as a filter tends to be insufficient. . Here, the average fiber diameter is a value calculated from a specific fiber diameter per 200 fibers constituting the nonwoven fabric, as shown in the fiber diameter measurement method described later, and a volume ratio (ratio in terms of volume) and Is a value calculated based on numerical values obtained from fiber diameter measurement, which will be described later.
　本発明の不織布は、見掛け密度が０．０５ｇ／ｃｍ３以上０．５０ｇ／ｃｍ３以下であり、かつ、最大細孔径が１０．０μｍ以下であることが好ましい。見掛け密度は、より好ましくは、０．０８ｇ／ｃｍ３以上０．３０ｇ／ｃｍ３以下である。さらに好ましくは０．１１ｇ／ｃｍ３以上０．１５ｇ／ｃｍ３以下である。最大細孔径を小さくするために、不織布を積層したりカレンダー加工したり、適宜調整しても良いが、単層の不織布とすることが取り扱い性やコスト面でより好ましい。 Nonwoven fabric of the present invention has an apparent density of the 0.05 g / cm 3 or more 0.50 g / cm 3 or less, and the maximum pore diameter is preferably not more than 10.0 [mu] m. The apparent density is more preferably 0.08 g / cm 3 or more and 0.30 g / cm 3 or less. More preferably, it is 0.11 g / cm 3 or more and 0.15 g / cm 3 or less. In order to reduce the maximum pore diameter, the nonwoven fabric may be laminated, calendered, or adjusted as appropriate, but a single-layer nonwoven fabric is more preferable in terms of handleability and cost.
　上記において、見掛け密度とは、後述するように不織布の平均厚みおよび平均目付を測定し、次の式によって算出した値である。見掛け密度が小さいものほど嵩高い不織布であるといえる。
　見掛け密度（ｇ／ｃｍ３）＝｛平均目付（ｇ／ｍ２）／平均厚み（ｍｍ）｝／１０００ In the above, the apparent density is a value obtained by measuring the average thickness and the average basis weight of the nonwoven fabric as described later and calculating by the following formula. It can be said that the smaller the apparent density, the bulkier the nonwoven fabric.
Apparent density (g / cm 3 ) = {average basis weight (g / m 2 ) / average thickness (mm)} / 1000
　前記平均目付は、不織布の取扱いにおいて次工程での作業性等を考慮すると高目付であればあるほどよく１０ｇ／ｍ２以上であることが好ましい。さらに、前述したとおり、単層で平均目付が１０ｇ／ｍ２以上である不織布を得ることが、取り扱い性やコスト面でより好ましい。 The average basis weight is preferably 10 g / m 2 or more as the basis weight increases as the basis weight increases in consideration of workability in the next step in handling the nonwoven fabric. Furthermore, as described above, it is more preferable in terms of handleability and cost to obtain a nonwoven fabric having a single layer and an average basis weight of 10 g / m 2 or more.
　本発明の不織布を構成する繊維は、熱可塑性樹脂からなる。熱可塑性樹脂であれば、特に限定されることはなく、ポリエステル、ポリオレフィン、ポリアミド、ポリフェニレンサルファイド等を用いることができる。なかでもポリプロピレン極細繊維であることが好ましい。ポリプロピレン樹脂は、公知のものを用いることができるが、後述するメルトブロー法によって製造する場合には、ＭＦＲ（メルトフローレイト）が１０ｇ／１０分以上２０００ｇ／１０分以下の範囲にあることが好ましい。樹脂の物性値を示すＭＦＲは、ＪＩＳ　Ｋ７２１０－１の標準的試験方法により測定される。ポリプロピレン樹脂については、測定条件２．１６ｋｇ、２３０℃（ＪＩＳ　Ｋ６９２１－２においてポリプロピレン樹脂について定められた条件）として測定した値である。 The fibers constituting the nonwoven fabric of the present invention are made of a thermoplastic resin. If it is a thermoplastic resin, it will not specifically limit, Polyester, polyolefin, polyamide, polyphenylene sulfide, etc. can be used. Of these, polypropylene microfibers are preferred. Although a well-known thing can be used for a polypropylene resin, when manufacturing by the melt blow method mentioned later, it is preferable that MFR (melt flow rate) exists in the range of 10 g / 10min or more and 2000 g / 10min or less. The MFR indicating the physical property value of the resin is measured by a standard test method of JIS K7210-1. For the polypropylene resin, it is a value measured under measurement conditions of 2.16 kg and 230 ° C. (conditions determined for polypropylene resin in JIS K6921-2).
　また、前記不織布は、メルトブロー不織布であることが好ましい。メルトブロー法では、溶融した樹脂を紡糸ノズルから繊維状に吐出させるときに、吐出された繊維状の溶融樹脂に両側面から圧縮ガス（例えば空気）をあてるとともに、ガスを随伴させることで繊維径を小さくすることができる。このように、メルトブロー法によると、極細繊維を含む平均繊維径が０．８０μｍ以下の不織布を容易に得ることができるため、好ましい。 The nonwoven fabric is preferably a melt blown nonwoven fabric. In the melt blow method, when a molten resin is discharged into a fiber form from a spinning nozzle, a compressed gas (for example, air) is applied to both sides of the discharged fibrous molten resin, and the fiber diameter is adjusted by accompanying the gas. Can be small. Thus, the melt-blowing method is preferable because a nonwoven fabric having an average fiber diameter including ultrafine fibers of 0.80 μm or less can be easily obtained.
　また、本発明の不織布の製造方法は、メルトブロー法において、紡糸ノズル当たりの樹脂吐出量を０．０１ｇ／分以上とし、ダイ圧力を２．３ＭＰａ以上にすることを特徴とする。ダイ圧力が２．３ＭＰａを下回る場合は、口金より紡出されるポリマーの直進性が失われ、紡糸不安定となるため、ショットと呼ばれる塊状ポリマーとなって不織布上に噴射される。ここで、ダイ圧力の上限値は１０ＭＰａ程度であるが、これは標準的な現行装置上の制約であるため、前記制約が解消すればこの上限に限定されるものではない。 The non-woven fabric production method of the present invention is characterized in that, in the melt-blowing method, the resin discharge amount per spinning nozzle is 0.01 g / min or more and the die pressure is 2.3 MPa or more. When the die pressure is less than 2.3 MPa, the straightness of the polymer spun from the die is lost and the spinning becomes unstable, so that it becomes a block polymer called a shot and is sprayed onto the nonwoven fabric. Here, the upper limit value of the die pressure is about 10 MPa. However, this is a standard restriction on the current apparatus, and therefore the upper limit value is not limited to this upper limit as long as the restriction is eliminated.
　平均繊維径が０．８０μｍ以下、かつ、繊維径が１．０μｍ以下の繊維の体積比率が４０％未満といった不織布を得るには、紡糸ノズル当たりの樹脂吐出量を０．０１ｇ／分以上とすることが必要である。前記樹脂吐出量を０．０１ｇ／分より少なくすると、繊維径が、例えば１．０μｍ以下の細い繊維をより多く紡糸できるが、細い繊維の比率が大きくなりすぎてしまう。そのため、繊維間の融着が弱くなり、シートの強度を維持できず、工程通過時に、シートが伸びたり、破断してしまう。さらに、口金噴射後の繊維をシート状に捕集するサクション設備において、細い繊維が捕集しきれずに、吹き流れ風綿と呼ばれる綿屑が発生する。前記樹脂吐出量を０．０１ｇ／分以上とすることで、例えば繊維径が１．０μｍを超える太い繊維が一部存在するようになる。この太い繊維によって、不織布の繊維間融着が強くなり、高強度のシートが得られる。さらには、太い繊維が細い繊維を絡め取るため、風綿の発生を抑制し、高目付化することも可能である。前記樹脂吐出量は０．２ｇ／分以下であることが好ましい。前記樹脂吐出量が多すぎると、太い繊維の割合が多くなりすぎるため、好ましくない。 In order to obtain a nonwoven fabric having an average fiber diameter of 0.80 μm or less and a volume ratio of fibers having a fiber diameter of 1.0 μm or less of less than 40%, the resin discharge rate per spinning nozzle is 0.01 g / min or more. It is necessary. If the resin discharge rate is less than 0.01 g / min, more fine fibers having a fiber diameter of, for example, 1.0 μm or less can be spun, but the ratio of the fine fibers becomes too large. Therefore, the fusion between the fibers is weakened, the strength of the sheet cannot be maintained, and the sheet is stretched or broken during the process. Furthermore, in the suction equipment for collecting the fibers after the injection of the die into a sheet shape, fine fibers called blown cotton are generated without collecting the fine fibers. By setting the resin discharge rate to 0.01 g / min or more, for example, some thick fibers having a fiber diameter exceeding 1.0 μm are present. By this thick fiber, the inter-fiber fusion of the nonwoven fabric becomes strong, and a high-strength sheet is obtained. Furthermore, since the thick fibers entangle the thin fibers, the occurrence of fluff can be suppressed and the basis weight can be increased. The resin discharge rate is preferably 0.2 g / min or less. If the resin discharge amount is too large, the proportion of thick fibers increases too much, which is not preferable.
　本発明の不織布の製造方法においては、樹脂の物性値を示すＭＦＲが、１０ｇ／１０分以上２０００ｇ／１０分以下の範囲にある原料樹脂を用いることが好ましい。樹脂の物性値を示すＭＦＲは、樹脂の種類に応じて測定温度が規定されており、例えば、ポリプロピレンでは測定温度は２３０℃である。ダイ温度は一般的には、樹脂の物性値を示すＭＦＲの測定温度近辺の温度に設定されるため、所望の不織布を製造するためには、所定の範囲内のＭＦＲを有することを樹脂選択の指標とすることが好ましい。 In the method for producing a nonwoven fabric of the present invention, it is preferable to use a raw material resin having an MFR indicating a physical property value of the resin in a range of 10 g / 10 min to 2000 g / 10 min. The measurement temperature of the MFR indicating the physical property value of the resin is regulated according to the type of the resin. For example, the measurement temperature is 230 ° C. for polypropylene. Since the die temperature is generally set to a temperature in the vicinity of the MFR measurement temperature indicating the physical property value of the resin, in order to produce a desired nonwoven fabric, it is necessary to select a resin having an MFR within a predetermined range. It is preferable to use it as an index.
　このように、本発明の不織布の製造方法でメルトブロー不織布を製造すると、前記で規定したような不織布を好適に得ることができる。 Thus, when a melt blown nonwoven fabric is produced by the nonwoven fabric production method of the present invention, a nonwoven fabric as defined above can be suitably obtained.
（実施例１）
　メルトブロー不織布製造装置を用いて、ポリプロピレン樹脂を原料として不織布を製造した。本実施例において原料は、ポリプロピレン樹脂Ａ（商品名「ＡｃｈｉｅｖｅＴＭ６９３６Ｇ２」、Ｅｘｘｏｎ　Ｍｏｂｉｌ社製、ＭＦＲ＝１５５０）を用いた。前記のポリプロピレン樹脂を用い、前記製造装置においてダイの設定温度を２６０℃、直径０．１２ｍｍの紡糸ノズル１穴当たりの吐出量を０．０１７ｇ／分とした。前記紡糸ノズルの両側からは、設定温度２９０℃にて加熱圧縮された空気を吹き付け、前記紡糸ノズルから１００ｍｍの距離の捕集装置に紡糸させ、平均目付を３０ｇ／ｍ２としたメルトブロー不織布を得た。このときのダイ圧力は２．３ＭＰａであった。得られた不織布の物性を下記記載の方法で測定した。結果を表１に示す。また、得られた不織布の繊維径分布のヒストグラムを図１（ａ）に、１枚の試験片についての引張試験におけるＳ－Ｓカーブを図２において実線で示す。 (Example 1)
Using a melt blown nonwoven fabric manufacturing apparatus, a nonwoven fabric was manufactured using polypropylene resin as a raw material. In this example, polypropylene resin A (trade name “Achieve ™ 6936G2”, manufactured by Exxon Mobil, MFR = 1550) was used as a raw material. The polypropylene resin was used, and the set temperature of the die was 260 ° C. and the discharge rate per spinning nozzle hole having a diameter of 0.12 mm was 0.017 g / min in the manufacturing apparatus. From both sides of the spinning nozzle, air heated and compressed at a set temperature of 290 ° C. is blown and spun into a collecting device at a distance of 100 mm from the spinning nozzle to obtain a melt blown nonwoven fabric having an average basis weight of 30 g / m 2. It was. The die pressure at this time was 2.3 MPa. The physical properties of the obtained nonwoven fabric were measured by the methods described below. The results are shown in Table 1. In addition, a histogram of the fiber diameter distribution of the obtained nonwoven fabric is shown in FIG. 1A, and an SS curve in a tensile test for one test piece is shown by a solid line in FIG.
（実施例２）
　原料としてＭＦＲ＝８５０のポリプロピレン樹脂Ｂを用いた。ダイの設定温度を２４０℃とし、加熱圧縮された空気の設定温度を２３０℃にした以外は、実施例１と同様にして不織布を得た。このときのダイ圧力は２．９ＭＰａであった。得られた不織布の物性を下記記載の方法で測定した。結果を表１に示す。得られた不織布の繊維径分布のヒストグラムを図１（ｂ）に、１枚の試験片についての引張試験におけるＳ－Ｓカーブを図２において破線で示す。 (Example 2)
Polypropylene resin B with MFR = 850 was used as a raw material. A nonwoven fabric was obtained in the same manner as in Example 1 except that the set temperature of the die was 240 ° C and the set temperature of the heated and compressed air was 230 ° C. The die pressure at this time was 2.9 MPa. The physical properties of the obtained nonwoven fabric were measured by the methods described below. The results are shown in Table 1. A histogram of the fiber diameter distribution of the obtained nonwoven fabric is shown in FIG. 1B, and an SS curve in a tensile test for one test piece is shown by a broken line in FIG.
（比較例１）
　紡糸ノズル１穴当たりの吐出量を０．００８ｇ／分、加熱圧縮された空気の設定温度を１９０℃にした以外は、実施例２と同様にして不織布を得た。このときのダイ圧力は２．６ＭＰａであった。得られた不織布の物性を下記記載の方法で測定した。結果を表１に示す。また、得られた不織布の繊維径分布のヒストグラムを図１（ｃ）に、１枚の試験片についての引張試験におけるＳ－Ｓカーブを図２において一点鎖線で示す。 (Comparative Example 1)
A nonwoven fabric was obtained in the same manner as in Example 2, except that the discharge amount per hole of the spinning nozzle was 0.008 g / min and the set temperature of the heated and compressed air was 190 ° C. The die pressure at this time was 2.6 MPa. The physical properties of the obtained nonwoven fabric were measured by the methods described below. The results are shown in Table 1. In addition, a histogram of the fiber diameter distribution of the obtained nonwoven fabric is shown in FIG. 1 (c), and an SS curve in a tensile test for one test piece is shown by a one-dot chain line in FIG.
（比較例２）
　紡糸ノズル１穴当たりの吐出量を０．００８ｇ／分、加熱圧縮された空気の設定温度を２９０℃に使用した以外は、実施例２と同様にして不織布を得た。このときのダイ圧力は２．０ＭＰａであった。この条件下では、ショットが多発したため、均一なシートが得られなかった。ダイの圧力が低下し、紡糸性が悪化したためである。 (Comparative Example 2)
A nonwoven fabric was obtained in the same manner as in Example 2, except that the discharge amount per hole of the spinning nozzle was 0.008 g / min, and the set temperature of the heated and compressed air was 290 ° C. The die pressure at this time was 2.0 MPa. Under these conditions, shots occurred frequently, and a uniform sheet could not be obtained. This is because the die pressure was lowered and the spinnability deteriorated.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　実施例１の不織布は、平均繊維径が０．６１μｍであり、かつ、１．０μｍ以下の繊維の体積比率が２５．２％であった。引張強度は２１．４Ｎ／５ｃｍ、５％伸張時応力は１８．３Ｎ／５ｃｍと非常に高い値を示した。極細繊維を含みなおかつ、工程通過性に優れる不織布が得られた。 The nonwoven fabric of Example 1 had an average fiber diameter of 0.61 μm and a fiber volume ratio of 1.0 μm or less of 25.2%. The tensile strength was 21.4 N / 5 cm, and the stress at 5% elongation was as high as 18.3 N / 5 cm. A nonwoven fabric containing ultrafine fibers and having excellent process passability was obtained.
　実施例２の不織布は、平均繊維径が０．６８μｍであり、かつ、１．０μｍ以下の繊維の体積比率が２４．３％であった。引張強度は１９．１Ｎ／５ｃｍ、５％伸張時応力は１５．４Ｎ／５ｃｍと非常に高い値を示した。極細繊維を含みなおかつ、工程通過性に優れる不織布が得られた。 The nonwoven fabric of Example 2 had an average fiber diameter of 0.68 μm and a fiber volume ratio of 1.0 μm or less was 24.3%. The tensile strength was 19.1 N / 5 cm, and the stress at 5% elongation was as very high as 15.4 N / 5 cm. A nonwoven fabric containing ultrafine fibers and having excellent process passability was obtained.
　一方、比較例１の不織布は、平均繊維径が０．６３μｍであるが、１．０μｍ以下の繊維の体積比率は４０．０％であった。引張強度は７．１Ｎ／５ｃｍ、５％伸張時応力は１．１Ｎ／５ｃｍと非常に低い値を示した。太い繊維が少ないため、高強度が得られず、極細繊維を含んでいるものの、工程通過時にシートが破断する等した。 On the other hand, the nonwoven fabric of Comparative Example 1 had an average fiber diameter of 0.63 μm, but the volume ratio of fibers of 1.0 μm or less was 40.0%. The tensile strength was 7.1 N / 5 cm, and the stress at 5% elongation was as low as 1.1 N / 5 cm. Since there are few thick fibers, high strength could not be obtained, and although the sheet contained ultrafine fibers, the sheet broke during the process.
　以上のように、実施例においては、極細繊維を有しながら、なおかつシートを加工する際の強度に優れた不織布を得ることができた。実施例で得られた不織布は、比較例で得られた不織布と比べて、１．０μｍを超えるような太い繊維径の繊維を体積比率にて、実施例１では約７５％、実施例２では約７６％も有しているにも拘らず最大細孔径が小さく、フィルター性能の観点からはより均一性に優れているといえる。 As described above, in the examples, it was possible to obtain a nonwoven fabric having ultrafine fibers and having excellent strength when processing a sheet. In the nonwoven fabric obtained in the example, compared with the nonwoven fabric obtained in the comparative example, fibers having a thick fiber diameter exceeding 1.0 μm in volume ratio, about 75% in Example 1, and in Example 2 Despite having about 76%, the maximum pore diameter is small, and it can be said that it is more uniform from the viewpoint of filter performance.
　なお、実施例および比較例で得られた上記の不織布の特性は以下の方法で測定した。 In addition, the characteristic of said nonwoven fabric obtained by the Example and the comparative example was measured with the following method.
［平均厚み］
　平均厚みは、得られた不織布を２５０ｍｍ×２５０ｍｍにカットし、それぞれの辺の中央部分の４ヶ所をダイヤルシックネスゲージにより測定し、得られた値から、平均値を算出し、小数点以下第３位を四捨五入することにより求めた。 [Average thickness]
The average thickness is obtained by cutting the obtained non-woven fabric into 250 mm × 250 mm, measuring the central part of each side with a dial thickness gauge, calculating the average value from the obtained values, and placing the third decimal place Was calculated by rounding off.
［平均目付］
　平均目付は、得られた不織布を２５０ｍｍ×２５０ｍｍにカットした試験片を３枚採取し、各々の質量を電子天秤にて測定して３枚の平均値を算出し、この平均値を１６倍し、小数点以下第２位を四捨五入することにより求めた。 [Average weight]
The average basis weight is obtained by collecting three test pieces obtained by cutting the obtained nonwoven fabric into 250 mm × 250 mm, measuring each mass with an electronic balance, calculating the average value of the three pieces, and multiplying the average value by 16 Calculated by rounding off the second decimal place.
［見掛け密度］
　見掛け密度は前述の平均厚みおよび平均目付から、下記式より算出し、小数点以下第４位を四捨五入した。
　見掛け密度（ｇ／ｃｍ３）＝｛平均目付（ｇ／ｍ２）／平均厚み（ｍｍ）｝／１０００ [Apparent density]
The apparent density was calculated from the above average thickness and average basis weight by the following formula, and rounded off to the fourth decimal place.
Apparent density (g / cm 3 ) = {average basis weight (g / m 2 ) / average thickness (mm)} / 1000
［平均繊維径、繊維本数比率、繊維体積比率］
　平均繊維径、繊維本数比率、および繊維体積比率は、得られた不織布を電子顕微鏡にて５０００倍で撮影した写真から、繊維径を測定することにより求めた。平均繊維径は、写真１０枚から任意に、合計本数２００本の繊維について直径０．０１μｍオーダーまで繊維径を測定し、それらを平均し、小数点以下第３位を四捨五入して求めた。繊維径が１．０μｍ以下の繊維の本数比率は、前記の繊維２００本のうち繊維径が１．０μｍ以下となる繊維の本数を、全測定繊維本数にて除し、百分率で表した。繊維径が１．０μｍ以下の繊維の体積比率は、前記の繊維２００本のうち１．０μｍ以下となる繊維について、繊維径を各々２乗した値の総和を、全測定繊維について繊維径を各々２乗した値の総和にて除し、百分率で小数点以下第２位を四捨五入して算出した。 [Average fiber diameter, fiber number ratio, fiber volume ratio]
The average fiber diameter, the fiber number ratio, and the fiber volume ratio were determined by measuring the fiber diameter from a photograph of the obtained nonwoven fabric taken at 5000 times with an electron microscope. The average fiber diameter was determined by arbitrarily measuring the fiber diameter from 10 photos to 200 μm diameter on the order of 0.01 μm, averaging them, and rounding off to the third decimal place. The number ratio of fibers having a fiber diameter of 1.0 μm or less was expressed as a percentage by dividing the number of fibers having a fiber diameter of 1.0 μm or less out of the 200 fibers by the total number of measured fibers. The volume ratio of the fibers having a fiber diameter of 1.0 μm or less is the sum of values obtained by squaring the fiber diameters for the fibers having a diameter of 1.0 μm or less among the 200 fibers, and the fiber diameters for all the measured fibers. Divided by the sum of the squared values and rounded off to one decimal place.
［Ｄｗ／Ｄｎ］
　繊維径Ｄｉの繊維がＮｉ本存在するとき、数平均繊維径Ｄｎと重量平均繊維径Ｄｗは次のように求められる。Ｄｗ／Ｄｎは、これらを基に算出した繊維径分布を表す指標であり、１に近いほど、より繊維径分布が均一である。
　Ｄｎ＝ΣＸｉＤｉ＝Σ（ＮｉＤｉ）／Σ（Ｎｉ）
　（式中、Ｘｉ＝繊維径Ｄｉの存在比率＝Ｎｉ／ΣＮｉである。）
　Ｄｗ＝ΣＷｉＤｉ＝Σ（ＮｉＤｉ２）／Σ（ＮｉＤｉ）
　（式中、Ｗｉ＝繊維径Ｄｉの重量分率＝ＮｉＤｉ／ΣＮｉＤｉである。） [Dw / Dn]
When Ni fibers having a fiber diameter Di are present, the number average fiber diameter Dn and the weight average fiber diameter Dw are obtained as follows. Dw / Dn is an index representing the fiber diameter distribution calculated based on these, and the closer to 1, the more uniform the fiber diameter distribution.
Dn = ΣXiDi = Σ (NiDi) / Σ (Ni)
(Where Xi = abundance ratio of fiber diameter Di = Ni / ΣNi)
Dw = ΣWiDi = Σ (NiDi 2 ) / Σ (NiDi)
(In the formula, Wi = weight fraction of fiber diameter Di = NiDi / ΣNiDi.)
［最大細孔径］
　バブルポイント法（ＪＩＳ　Ｋ３８３２（１９９０））により、最大細孔径を求めた。測定は、自動細孔径分布測定器（型式「ＣＦＰ－１２００ＡＥＸＣＳ」、Ｐｏｒｏｕｓ　ｍａｔｅｒｉａｌｓ，Ｉｎｃ社製）を用い、下記試験方法によって得られたバブルポイント値から下記式１を用いて最大細孔径を算出し、小数点以下第２位を四捨五入した。
（試験方法）
　不織布の試験片に試薬（ＧＡＬＷＩＣＫ、表面張力１５．９ｄｙｎ／ｃｍ＝１５．９ｍＮ／ｍ）を含浸させて完全に濡らし、液体（試薬）とサンプル（不織布）との接触角をゼロとする。前記試薬を含浸させた不織布の試験片を、前記測定器のホルダーにセットし測定する。
　　ｄ＝Ｃｒ／Ｐ　　　（式１）
　　　　　ｄ＝最大細孔径　（μｍ）
　　　　　ｒ＝試薬の表面張力（１５．９ｍＮ／ｍ）
　　　　　Ｐ＝差圧　（Ｐａ）
　　　　　Ｃ＝圧力定数（２８６０） [Maximum pore size]
The maximum pore diameter was determined by the bubble point method (JIS K3832 (1990)). For the measurement, an automatic pore size distribution measuring device (model “CFP-1200AEXCS”, manufactured by Porous materials, Inc.) was used, and the maximum pore size was calculated using the following formula 1 from the bubble point value obtained by the following test method. Rounded to the second decimal place.
(Test method)
A non-woven fabric test piece is impregnated with a reagent (GALWICK, surface tension of 15.9 dyn / cm = 15.9 mN / m) and completely wetted so that the contact angle between the liquid (reagent) and the sample (nonwoven fabric) becomes zero. A non-woven fabric test piece impregnated with the reagent is set in a holder of the measuring instrument and measured.
d = Cr / P (Formula 1)
d = maximum pore diameter (μm)
r = surface tension of reagent (15.9 mN / m)
P = differential pressure (Pa)
C = pressure constant (2860)
［平均細孔径］
　前記自動細孔径分布測定器に、乾燥した不織布の試験片をセットし、一方の面にかける空気圧を徐々に増大させて、空気が乾燥試験片を透過するときの圧力と流量との関係を示す乾き流量曲線（ＤＲＹ　ＦＬＯＷ　ＣＵＲＶＥ）を測定した。このとき、空気が乾燥試験片を透過し始めたときの圧力をＰ１とする。次いで、前記乾き流量曲線を基に、透過流量を１／２としたハーフドライ流量曲線を作成した。そして、前記試験片を前記試薬に浸漬した後に、同様の測定を行い、濡れ流量曲線（ＷＥＴ　ＦＬＯＷ　ＣＵＲＶＥ）を得た。
　平均細孔径ｄｍは、ハーフドライ流量曲線と濡れ流量曲線との交点における圧力Ｐ２と、前記Ｐ１との差圧Ｐｃから、下記式２を用いて算出し、小数点以下第２位を四捨五入した。
　　ｄｍ＝Ｃｒ／Ｐｃ　　　（式２）
　　　　　ｄｍ＝平均細孔径　（μｍ）
　　　　　ｒ＝液体の表面張力（１５．９ｍＮ／ｍ）
　　　　　Ｐｃ＝差圧（Ｐ２－Ｐ１）　（Ｐａ）
　　　　　Ｃ＝圧力定数（２８６０） [Average pore diameter]
A test piece of dry nonwoven fabric is set in the automatic pore size distribution measuring instrument, and the air pressure applied to one surface is gradually increased to show the relationship between the pressure and the flow rate when air passes through the dry test piece. A dry flow curve (DRY FLOW CURVE) was measured. At this time, let P1 be the pressure when the air begins to permeate the dry test piece. Next, based on the dry flow rate curve, a half dry flow rate curve with a permeate flow rate of 1/2 was created. And after the said test piece was immersed in the said reagent, the same measurement was performed and the wetting flow rate curve (WET FLOW CURVE) was obtained.
The average pore diameter d m is the pressure P 2 in the intersection of the half-dry flow curve and wet flow curve, from the differential pressure P c of the P 1, is calculated using the following equation 2, the second decimal place Rounded off.
d m = Cr / P c (Formula 2)
d m = average pore diameter (μm)
r = surface tension of liquid (15.9 mN / m)
P c = differential pressure (P 2 −P 1 ) (Pa)
C = pressure constant (2860)
［通気度］
　得られた不織布を２００ｍｍ×２００ｍｍにカットした試験片を５枚採取し、ＪＩＳ　Ｌ　１０９６（Ａ法：フラジール形法）に準拠した方法にて、通気性試験／通気度測定器（ＴＥＸＴＥＳＴ社製　ＦＸ３３００）を用いて測定した。測定においては、１ｃｍ２の面積に通過する空気量（ｃｍ３／ｃｍ２／ｓｅｃ）を求め、試験片５枚の前記空気量の平均値から、小数点以下第２位を四捨五入して通気度とした。 [Air permeability]
Five test pieces obtained by cutting the obtained non-woven fabric into 200 mm × 200 mm were collected and subjected to a breathability test / permeability meter (FX3300 manufactured by TEXTEST) in accordance with JIS L 1096 (A method: Frazier type method). ). In the measurement, the amount of air passing through an area of 1 cm 2 (cm 3 / cm 2 / sec) is obtained, and the air permeability is calculated by rounding off the second decimal place from the average value of the air amount of five test pieces. did.
［引張強度、５％伸張時応力］
　得られた不織布をシートの長さ方向に対して、長さ２００ｍｍ×幅５０ｍｍにカットした試験片をシート全幅に対し、等間隔で５枚採取し、ＪＩＳ　Ｌ　１９１３に準拠した方法にて、掴み間隔５０ｍｍ、引張速度３００ｍｍ／分にて試験を行い、最大強度を示した値を引張強度とした。また、得られたＳ－Ｓカーブから、５％伸張時の強度を読み取り、５％伸張時応力とした。試験片５枚の前記引張強度および、５％伸張時応力の平均値の小数点以下第２位を四捨五入した。 [Tensile strength, stress at 5% elongation]
Five test specimens obtained by cutting the obtained non-woven fabric into a length of 200 mm × width of 50 mm with respect to the length direction of the sheet were sampled at regular intervals with respect to the full width of the sheet, and gripped by a method in accordance with JIS L 1913. The test was performed at an interval of 50 mm and a tensile speed of 300 mm / min, and the value indicating the maximum strength was taken as the tensile strength. Further, from the obtained SS curve, the strength at 5% elongation was read and used as the stress at 5% elongation. The second decimal place of the average value of the tensile strength and 5% elongation stress of the five test pieces was rounded off.
　本発明の不織布は、太い繊維を一定以上の割合で含みながらも均一性に優れ、極細繊維を含みなおかつ高強度であることから、各種フィルター用途に好適に用いることができ、特に液体フィルター用途に好適に用いることができる。また、本発明の不織布の製造方法によると、均一性に優れ、極細繊維を含みなおかつ高強度な不織布を製造することができる。 The non-woven fabric of the present invention is excellent in uniformity while containing thick fibers at a certain ratio or more, and since it contains ultrafine fibers and has high strength, it can be suitably used for various filter applications, particularly for liquid filter applications. It can be used suitably. Moreover, according to the method for producing a nonwoven fabric of the present invention, it is possible to produce a nonwoven fabric that is excellent in uniformity, contains ultrafine fibers, and has high strength.

Claims (4)

  1. 平均繊維径が０．８μｍ以下であり、かつ、繊維径が１．０μｍ以下の繊維の体積比率が４０％未満であることを特徴とする不織布。 A nonwoven fabric characterized by having an average fiber diameter of 0.8 μm or less and a volume ratio of fibers having a fiber diameter of 1.0 μm or less of less than 40%.
  2. 平均目付が１０ｇ／ｍ２以上であることを特徴とする、請求項１記載の不織布。 The nonwoven fabric according to claim 1, wherein an average basis weight is 10 g / m 2 or more.
  3. 長手方向の５％伸張時応力が、５．０Ｎ／５ｃｍ以上であることを特徴とする、請求項１または２記載の不織布。 The nonwoven fabric according to claim 1 or 2, wherein a stress at 5% elongation in the longitudinal direction is 5.0 N / 5 cm or more.
  4. メルトブロー法において、紡糸ノズル当たりの樹脂吐出量を０．０１ｇ／分以上とし、ダイ部分のポリマー圧力が２．３ＭＰａ以上となるようにダイ温度を設定することを特徴とする不織布の製造方法。
          A method for producing a nonwoven fabric, characterized in that, in the melt blowing method, a resin discharge amount per spinning nozzle is set to 0.01 g / min or more and a die temperature is set so that a polymer pressure in a die portion is 2.3 MPa or more.
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20230028580A (en) 2021-05-26 2023-02-28 타피러스 컴퍼니 리미티드 Melt blown nonwoven fabric and filter containing the same
JP7445770B2 (en) 2020-01-07 2024-03-07 チュンイェン ヂョン Bacterial cellulose microfiber/alginate fiber composite material supporting nano zinc oxide

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007023391A (en) * 2005-07-12 2007-02-01 Toray Ind Inc Nonwoven fabric composed of ultrafine fiber and method for producing the same
US20080318024A1 (en) * 2007-06-22 2008-12-25 3M Innovative Properties Company Meltblown fiber web with staple fibers
JP2009534548A (en) * 2006-04-18 2009-09-24 ヒルズ， インコーポレイテッド Method and apparatus for the production of meltblown nanofibers
US20100219138A1 (en) * 2009-02-27 2010-09-02 Scheerlinck Philippe M Melt blown polymeric filtration medium for high efficiency fluid filtration
WO2012014501A1 (en) * 2010-07-29 2012-02-02 三井化学株式会社 Non-woven fiber fabric, and production method and production device therefor
JP2012510006A (en) * 2008-11-25 2012-04-26 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Nonwoven polymer web
WO2012102398A1 (en) * 2011-01-28 2012-08-02 タピルス株式会社 Melt-blown nonwoven fabric comprising ultra-fine fibers, production method therefor, and device for producing same
WO2015171707A1 (en) * 2014-05-07 2015-11-12 Biax-Fiberfilm A non-woven web
WO2016148174A1 (en) * 2015-03-16 2016-09-22 東レ・ファインケミカル株式会社 Nonwoven fabric and method for manufacturing same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2500844C2 (en) * 2008-12-25 2013-12-10 Као Корпорейшн Non-woven fabric and method of its production

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007023391A (en) * 2005-07-12 2007-02-01 Toray Ind Inc Nonwoven fabric composed of ultrafine fiber and method for producing the same
JP2009534548A (en) * 2006-04-18 2009-09-24 ヒルズ， インコーポレイテッド Method and apparatus for the production of meltblown nanofibers
US20080318024A1 (en) * 2007-06-22 2008-12-25 3M Innovative Properties Company Meltblown fiber web with staple fibers
JP2012510006A (en) * 2008-11-25 2012-04-26 イー・アイ・デュポン・ドウ・ヌムール・アンド・カンパニー Nonwoven polymer web
US20100219138A1 (en) * 2009-02-27 2010-09-02 Scheerlinck Philippe M Melt blown polymeric filtration medium for high efficiency fluid filtration
WO2012014501A1 (en) * 2010-07-29 2012-02-02 三井化学株式会社 Non-woven fiber fabric, and production method and production device therefor
WO2012102398A1 (en) * 2011-01-28 2012-08-02 タピルス株式会社 Melt-blown nonwoven fabric comprising ultra-fine fibers, production method therefor, and device for producing same
WO2015171707A1 (en) * 2014-05-07 2015-11-12 Biax-Fiberfilm A non-woven web
WO2016148174A1 (en) * 2015-03-16 2016-09-22 東レ・ファインケミカル株式会社 Nonwoven fabric and method for manufacturing same

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7445770B2 (en) 2020-01-07 2024-03-07 チュンイェン ヂョン Bacterial cellulose microfiber/alginate fiber composite material supporting nano zinc oxide
KR20230028580A (en) 2021-05-26 2023-02-28 타피러스 컴퍼니 리미티드 Melt blown nonwoven fabric and filter containing the same

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