WO2008038536A1

WO2008038536A1 - Split type composite long fiber, nonwoven fabric made of split type composite long fiber, and split-fiber nonwoven fabric

Info

Publication number: WO2008038536A1
Application number: PCT/JP2007/068042
Authority: WO
Inventors: Akio Matsubara; Shigeyuki Motomura; Chureerat Prahsarn
Original assignee: Mitsui Chemicals, Inc.
Priority date: 2006-09-25
Filing date: 2007-09-18
Publication date: 2008-04-03
Also published as: JP5334583B2; JPWO2008038536A1; TW200825225A

Abstract

A split type composite fiber which comprises a propylene polymer and an ethylene polymer and has improved suitability for splitting. The split type composite long fiber is made of a propylene polymer having an MFR as measured at 230°C under a load of 2,160 g of 40 g/10 min or higher and high-pressure-process low-density polyethylene, the propylene polymer part and the high-pressure-process low-density polyethylene part being in contact with each other. Also provided are: a nonwoven fabric comprising fibers which each is the split type composite long fiber; a split-fiber nonwoven fabric obtained by subjecting the nonwoven fabric to fiber splitting; and a process for producing the split-fiber nonwoven fabric.

Description

Specification

Split composite long fibers, non-woven fabrics composed of split composite long fibers, and split fiber non-woven fabrics

Technical field

TECHNICAL FIELD [0001] The present invention relates to a split composite long fiber excellent in splitting ability, which is an polyolefin polymer suitable for sanitary materials, filters, wipers, battery separators, and the like, a non-woven fabric having split composite long fiber strength, and a split fiber non-woven fabric. .

Background art

[0002] Nonwoven fabrics made of ultrafine fibers are excellent in flexibility, texture, etc., and are widely used as materials for clothing, usage !, sanitary goods, sanitary goods, wiping cloths, and the like. In recent years, it is expected to be used in clean rooms because of its excellent wiping performance.

[0003] As one method for obtaining ultrafine fibers, a multicomponent polymer is combined and spun into a split composite fiber, and the resulting split composite fiber is applied to physical stress and resin chemicals. A method of obtaining ultrafine fibers by dividing into a large number of fibers using a difference in shrinkage or the like is used. In general, polymers used for split type composite fibers are easily peelable, that is, incompatible polyesters and polyolefins, polyesters and polyamides, polyamides and polyolefins, etc. are used! / RU

[0004] Splitting composite fibers made of the same kind of polymer are inferior to the combination of polyester and polyolefin, so the splitting performance of the splitting composite fiber made of a propylene polymer and an ethylene polymer is improved. Various methods have been proposed. For example, a method in which a polypropylene-based resin and a polyethylene-based resin having different MFR ratios are used as a split-type composite fiber having a bent cross section (Patent Document 1; Japanese Patent Laid-Open No. 2000-328348), and a polypropylene resin having a molecular weight distribution of at least 5 And polyethylene-based resin, melt-spinning using a split-type composite nozzle having a hollow section at the center of the cross section, and a multi-stage drawing of 5 times or more to obtain a split-type composite fiber (Patent Document 2; 2002-220740) was proposed!

Patent Document 1: JP 2000-328348 A

Patent Document 2: Japanese Patent Laid-Open No. 2002-220740 [0005] However, in order to improve the splitting property, a special nozzle or multi-stage drawing is required to improve the splitting property, and while the spun composite long fiber is cooled by the cooling fluid, the tension is applied to the long fiber with the fluid. In addition, the thinning method has not yielded a non-woven fabric composed of split-type composite continuous fibers having excellent splitting properties.

Disclosure of the invention

Problems to be solved by the invention

[0006] As a result of various studies for the purpose of improving the splitability of a split type composite fiber composed of a propylene-based polymer and an ethylene-based polymer, (A) a propylene-based polymer has a load of 2160 g. It has been found that (B) high-pressure low-density polyethylene can be used to improve the resolution by (A) a propylene polymer having an MFR at 230 ° C of 40 g / 10 min or more, and an ethylene polymer. It was.

Means for solving the problem

[0007] The present invention uses (A) a propylene polymer having a load of 2160 g and an MFR at 230 ° C of 40 g / 10 min or more and (B) a high-pressure low-density polyethylene, and (A) a propylene polymer. A split-type composite long fiber in which a part and (B) a high-pressure method low-density polyethylene part are in contact with each other, a non-woven fabric composed of force, split-type composite long fiber, and a split-fiber non-woven fabric obtained by dividing the non-woven fabric It is.

[0008] The present invention also provides a spinneret having a composite spinning nozzle comprising (A) a propylene-based polymer having a load of 2160 g and an MFR force of Og / 10 min at 230 ° C of 10 minutes or more and (B) a high-pressure low-density polyethylene. The composite filaments that are spun and spun from (A) the propylene polymer part and (B) the high-pressure method low-density polyethylene part are cooled by the cooling fluid, and the tension is applied to the filaments by the fluid. In addition, (A) Propylene polymer part is oriented and crystallized, and then collected and deposited on a collection belt to produce a non-woven fabric with split composite long fiber strength. The method and the manufacturing method of a split fiber nonwoven fabric are provided.

The invention's effect

[0009] The split-type long fibers of the present invention are excellent in splitting properties, and the resulting nonwoven fabric is made of an olefin polymer, so that it is lightweight and has excellent water resistance and flexibility. Brief Description of Drawings

FIG. 1 is a schematic view showing an example of a cross section of a composite long fiber according to the present invention.

[0011] The five forms (a) to (d) are listed. (E) is an example of the cross-sectional form after a division | segmentation process.

[0012] In the drawing, white and black portions represent resins to be combined.

BEST MODE FOR CARRYING OUT THE INVENTION

[0013] (A) Propylene polymer

The propylene-based polymer (A) relating to the split-type composite long fiber of the present invention has a melt flow rate (MFR; ASTM D-1238 load; 2160 gf, temperature; 230 ° C), MFR force 0 g / 10 min or more, Preferably in the range of 50-500 g / 10 min, more preferably 55-; lOOg / 10 min

[0014] When the (A) propylene-based polymer having an MFR force S of less than 40 g / 10 min is used, the split-type long fibers obtained are inferior in splitting properties.

Further, the ratio Mw / Mn of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the poly (A) propylene polymer is usually 1.5 to less than 5.0, and the spinnability is good. Further, 1.5 to 3.5 is preferable in that a composite fiber having particularly excellent fiber strength can be obtained. In the present invention, good spinnability means that yarn breakage does not occur during discharging from the spinning nozzle and during drawing, and filament fusion does not occur. If Mw / Mn is 5.0 or more, there is a large amount of high molecular weight, and yarn breakage is likely to occur.If Mw / Mn is 1.5 or less, filament fusion occurs due to crystallization delay during drawing. There is a problem that it is easy. In the present invention, Mw and Mn are measured by a known method using GPC (gel permeation chromatography).

[0015] The propylene-based polymer (A) according to the present invention is a homopolymer of propylene or propylene and a small amount of ethylene, 1-butene, 1-hexene, 4-methynole 1-pentene, 1-octene, Examples thereof include copolymers with α-olefin having 2 to 10 carbon atoms such as 1-decene. Such (ii) propylene-based polymer is preferably a polymer having a melting point (Tm) of 155 ° C or higher, more preferably 160 ° C or higher.

[0016] The (A) propylene-based polymer according to the present invention includes an antioxidant, a weather resistance stabilizer, a light resistance stabilizer, an antistatic agent, an antifogging agent, and the like, as long as the object of the present invention is not impaired. Professional Use force S to add additives such as anti-ocking agents, lubricants, nucleating agents, pigments, or other polymers as necessary.

[0017] (B) High-pressure low-density polyethylene

The (B) high-pressure method low-density polyethylene relating to the split-type composite continuous fiber of the present invention is a so-called polymer obtained by radical polymerization of ethylene under high pressure, and is an ethylene homopolymer or ethylene. It is a copolymer with a small amount of butyl acetate. The (B) high-pressure process low-density polyethylene is an ethylene obtained by copolymerizing ethylene and α-olefin having 3 to 10 carbon atoms under low pressure using a Ziegler catalyst, a meta-mouth catalyst, or the like. The so-called linear low density polyethylene (LLDPE) and Ziegler catalyst (low pressure 10-20 kg m ² ) or Philips catalyst or standard catalyst (medium pressure 30-; 100 kg m ² ) It is a polymer different from so-called high-density polyethylene (HDPE; density 0 · 950-0.970 g / cm ³ ) obtained by radical polymerization of ethylene.

[0018] The melt flow rate (MFR; ASTM D-1238 load; 2160gf, temperature; 190 ° C) of the (B) high-pressure low-density polyethylene according to the present invention is not particularly limited as long as it can be melt-spun. ! ~ LOOOg / 10 min, preferred <(between 10 and 500 g / 10 min, more preferred <(between 20 and; lOOg / 10 min.).

[0019] The melting point (Tm) of the (B) high-pressure method low-density polyethylene according to the present invention is preferably 90 to 110. C, more preferably (between 95 and 110; in the range of C, density is preferably (between 0.9.900-0. 935 g / cm ³ , more preferred (between 0.9.905—0. 925 g / cm ³ range) There is.

[0020] The (iii) high-pressure low-density polyethylene according to the present invention includes an antioxidant, a weather-resistant stabilizer, a light-resistant stabilizer, an anti-static agent, an anti-fogging agent, and the like as long as the object of the present invention is not impaired. Add power, additives, such as anti-blocking agents, lubricants, nucleating agents, pigments, or other polymers as needed.

[0021] Harmful key

The split-type composite long fiber of the present invention comprises the above (ii) propylene polymer and the above (ii) high pressure method low density polyethylene, and (ii) a propylene polymer portion and (iii) a high pressure method low density polyethylene. It is a split-type composite continuous fiber that is in contact with each other.

[0022] (ii) As propylene polymer, MFR at load of 2160g and 230 ° C is 40g / 10min. When (A) a propylene-based polymer is used, the split type composite continuous fiber obtained is inferior in splitting properties. (B) When linear low density polyethylene is used instead of high pressure method low density polyethylene However, the obtained split-type composite continuous fiber is inferior in splittability.

[0023] The shape (cross section) of the split-type composite continuous fiber is not particularly limited as long as (A) the propylene polymer portion and (B) the high-pressure method low-density polyethylene portion are in contact with each other. a) to l (e)], etc., but from the viewpoint of ensuring good spinnability, the distance from the center is equal! /, a curve consisting of a set of points. The shape of a so-called perfect circle (Fig. 1 (a) and (b)) is preferred.

The split-type composite long fibers of the present invention have the same orientation pattern and a degree of orientation of at least 0.80, preferably at least 0.82 propylene polymer part and ethylene polymer part. Is a split-type composite continuous fiber in contact with Here, the orientation mode indicates a tendency in which direction the structural elements in the molecular chain are selectively oriented with respect to the fiber axis as a whole.For example, a high degree of c-axis orientation means that the crystal lattice has a high degree of orientation. The c-axis is selectively oriented in the fiber axis direction, indicating a high ratio.

It is preferable that the orientation mode is the same and the degree of orientation is higher because both components are crystallized at the same time or because the splitting property is excellent! /.

[0024] The split composite long fibers of the present invention preferably have an orientation degree of the main orientation mode of the ethylene polymer of at least 0.70, more preferably 0.75 or more.

The orientation degree of the present invention is determined by using a wide-angle X-ray diffractometer (RINT2550, manufactured by Rigaku Corporation, attached device: fiber sample table, X-ray source: CuKa, output: 40 kV 370 mA, detector: scintillation counter) Are aligned in the fiber axis direction and fixed to the sample holder, and the orientation obtained by measuring the azimuth distribution strength of the crystal plane peak [polypropylene polymer: (110) plane, polyethylene polymer: (200) plane]. In the angular distribution curve (X-ray interference diagram), the degree of orientation in the fiber axis direction is calculated from the half-value width (α) of the peak according to the following formula and evaluated. When the orientation degree obtained by the following formula is less than 0.8, it is judged that the orientation is very low, and the orientation degree (F) = (180 ° — α) / 180 ° (α Is the peak half-value width in the azimuth distribution curve) The fineness of the split-type composite continuous fiber of the present invention is usually preferably 6 denier or less. If it is 6 denier or less, the fineness after splitting treatment can be reduced, and it is excellent in wiping property and flexibility. Further, the number of divisions of the (A) propylene polymer part and the ethylene polymer part forming the split-type composite long fiber is not particularly limited as long as it does not impair the splittability, but usually 4 to 48 splits. , Preferably in the range of 4 to 24 divisions. By setting the fineness of the split-type composite long fiber and the splitting of the composite fiber to be within the range, the fineness of the split fiber obtained by splitting the nonwoven fabric made of the composite fiber is set to 0.00;! To 2.00 Denier, preferably in the range of 0.001 -0.5 denier.

[0025] Nonwoven fabric composed of split composite long fibers

The nonwoven fabric composed of the split-type composite long fibers of the present invention is made of the split-type composite long fibers, and usually has a basis weight of 200 g / m ² , preferably 10 to 150 g / m ² . Moreover, the nonwoven fabric of this invention is heat-seal | bonded by methods, such as an embossing roll and ultrasonic fusion | bonding, as needed, about a split type composite long fiber group. The area (embossed area ratio) in the case of heat-sealing can be appropriately selected depending on the application, but is preferably 5 to 30%.

[0026] Split fiber nonwoven fabric

The split fiber non-woven fabric of the present invention forms a composite fiber by applying stress to the non-woven fabric composed of the split-type composite long fibers. (A) A propylene-based polymer portion and (B) a high-pressure method low-density polyethylene portion are split. The basis weight is usually 3 to 200 g / m ² , preferably 10 to 150 g / m ² .

[0027] The fineness of the split fibers forming the split fiber nonwoven fabric of the present invention is usually in the range of 0.00;! To 2.0 denier, preferably 0.001 to 0.5 denier.

[0028] Examples of stress applied to the nonwoven fabric composed of split-type composite long fibers include various known methods such as a method of applying a liquid such as water at a high pressure, a so-called high-pressure water flow method (water jet method), and a gear stretcher.

[0029] When a high-pressure water flow is applied to a nonwoven fabric composed of split-type composite continuous fibers that are deposited, in order to promote entanglement and the like, for example, before the split splitting and entanglement application step by high-pressure liquid flow, It is preferable to replace the air present between the constituent single yarns of the nonwoven fabric with water. Specifically, water may be added to the web. [0030] The high-pressure liquid flow can be obtained by injecting the liquid through a nozzle hole and increasing the pressure with a high-pressure pump. As for the nozzle hole, the hole diameter is usually 0.05 to 1. Omm, and more preferably in the range of 0.5;! To 0.5 mm. The pressure of the high-pressure liquid stream is usually in the range of 5 to 400 MPa, preferably 50 to 300 MPa. In addition, water or warm water is applied as the liquid for ease of handling, and it is preferable to use a known water quality measuring device with a specific resistance value of 10Μ Ω'cm or more, more preferably 15 純 Ω'cm or more. To do.

[0031] The distance between the nozzle hole and the nonwoven fabric is preferably about 1 to 15 cm. When this distance exceeds 15 cm, the energy that the liquid gives to the nonwoven fabric decreases, and splitting tends to reduce the effect of confounding. If it is less than 1 cm, the formation of the nonwoven fabric tends to be disturbed.

[0032] Generally, the nozzle holes of the high-pressure liquid flow are arranged in a row in a direction crossing the traveling direction of the nonwoven fabric. In the case of single-sided processing, in order to obtain a tightly entangled bond with uniform split splitting, it is better to carry out the injection holes in two or more rows, preferably three or more rows. The pressure of the high-pressure liquid stream is preferably low on the front side and high on the rear side in order to make the formation uniform.

[0033] Further, the appearance pattern, V, and loose pattern of the split fiber nonwoven fabric according to the present invention can be changed by appropriately selecting the pattern of the screen belt used when processing the high-pressure liquid flow.

Yes

[0034] The split fiber nonwoven fabric subjected to split splitting treatment with a high-pressure liquid flow is then subjected to drying and heat treatment after the excess water is removed by mechanical squeezing into a final product. The heat treatment temperature time can be selected not only to remove moisture but also to allow moderate shrinkage and promotion of crystallization. The heat treatment may be dry heat treatment or wet heat treatment! /.

[0035] Manufacturing method of split-type composite continuous fiber and nonwoven fabric

The non-woven fabric composed of the split-type composite long fibers and the split-type composite long fibers of the present invention is produced by a known melt-spun spinning method using (A) a propylene polymer and (B) a high-pressure low-density polyethylene. Force that can be obtained The spunbond method is preferred because it provides a good productivity and good splitting ability.

[0036] As a method for producing the split composite fiber nonwoven fabric of the present invention, a spunbond method will be described as an example. The above (A) propylene-based polymer and (B) high-pressure method low-density polyethylene are separately melted with an extruder or the like, and the respective melts are illustrated in FIGS. 1 (a) to 1 (e). Like, inside It is discharged from a spinneret having a composite spinning nozzle that has a hollow, radial, parallel or parallel IJ, or arc-shaped cross-sectional structure, and (A) a propylene-based polymer portion and (B) a high-pressure method. Spinning split type composite continuous fibers in which the low density polyethylene parts are in contact with each other. The spun split composite long fibers are cooled with a cooling fluid, and further, tension is applied to the long fibers with drawn air to obtain a predetermined fineness, and the fibers are collected as they are and collected to a predetermined thickness. . Next, heat embossing is performed as necessary by heat fusion using a hot embossing roll. In the case of heat fusion using a hot embossing roll, the embossing area ratio of the embossing roll is a force that can be appropriately determined. Usually, 5 to 30% is preferable.

[0037] At this time, by appropriately selecting a molding temperature, a spinning speed, and a cooling air temperature within a range in which spinnability is good, (A) a propylene-based polymer portion, preferably (A) a propylene-based polymer portion ( B) It is necessary to crystallize the high-density low-density polyethylene part within the above range.

[0038] Pollution II 1¾ method of non-woven fabric

The method for producing a split fiber nonwoven fabric of the present invention comprises: (A) a propylene-based polymer part and (B) a high-pressure process low-density polyethylene part by using the above-mentioned various known methods for a nonwoven fabric comprising split-type composite long fibers. Divide.

Example

[0039] Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0040] The physical property values and the like in Examples and Comparative Examples were measured by the following methods.

[0041] (1) Split ratio

The obtained split fiber non-woven fabric is embedded in an epoxy resin and cut with a microtome at the next step to obtain a sample piece. When this is observed with an electron microscope (S-3500N Scanning Electron Microscope manufactured by Hitachi, Ltd.), and the number of segments in the cross-section of the split fiber observed from the obtained cross-sectional image is 1, the split ratio is 100%. When the number of segments in the section of the split fibers observed was 2 or more, the split ratio was calculated by the following formula. This was observed for 50 fibers, and the average value was taken as the split ratio of the split fiber nonwoven fabric.

[0042] Splitting rate [%] = (Total number of segments-Number of segments of the split fiber cross section observed) / Total number of segments XI 00 Here, the total number of segments refers to the total number of segments forming the filament cross section of the split composite fiber. For example, in the case of a split type composite fiber having a filament cross section as shown in Figs. 1 (a), (b) and (d), the total segment is 8.

[0043] For example, when a split fiber cross section as shown in Fig. 1 (e) is observed in a filament with a total number of segments of 8 as shown in Fig. 1 (a), the number of segments of the observed split fiber cross section is assumed to be 3. Based on the above formula, the split ratio is 62.5%.

[0044] (2) Fineness

The obtained split fiber non-woven fabric is embedded in an epoxy resin and cut with a microtome in the next step to obtain a sample piece. Next, observe with an electron microscope (S-3500N scanning electron microscope manufactured by Hitachi, Ltd.), select 30 undivided filaments from the obtained cross-sectional image, calculate the cross-sectional area, and calculate the average value thereof. Further, the fineness of the undivided filament was obtained, and the fineness of the divided fiber was calculated by the following formula using the division ratio.

[0045] Fineness of the split fibers = undivided filament fineness / (total number of segments X split ratio / 100)

(3) Texture

The touch is evaluated by 10 evaluators, and the evaluation results are shown according to the following criteria.

[0046] ◎: Human power S felt good to touch, 10 out of 10 people,

〇: Human power S that feels good to touch, 9 to 7 out of 10 people,

△: Human power S felt good to touch, 6 to 3 out of 10 people,

X: 2 or less of 10 people who feel comfortable to touch.

[0047] (4) Flexibility (45 ° cantilever method)

In accordance with JIS L1096 (Section 6. 19.1 A), JIS Z 8703 (standard condition of test place) temperature 20 ± 2 ° C, humidity 65 ± 2% in a constant temperature room 20mm X 150mm Take 5 specimens in the flow direction (MD) and transverse direction (CD) respectively, and place the short side of the specimen on a smooth horizontal surface with a 45 ° slope with the scale base line aligned. Next, manually slide the specimen in the direction of the slope, and when the center point of one end of the specimen touches the slope, read the moving length of the other end on the scale. Bending / softening (bending / softening) is indicated by the length (mm) of the specimen moved, measured for each of the five front and back sides, and expressed as the average value in the flow direction (MD) and the transverse direction (CD). [0048] It is determined that the nonwoven fabric is more flexible as the bending resistance is lower. Generally, flexibility is judged to be good when the bending resistance (MD) and transverse direction (CD) are less than 25 mm. However, the required flexibility varies depending on the purpose of use, and so is not necessarily limited to this value.

[0049] (5) Tensile strength

Flow direction (MD) in a constant temperature room of 20 ± 2 ° C and humidity of 65 ± 2% specified in JIS Z8703 (standard condition of test place) in accordance with JIS L1906 (6.12.1 A method) Tensile strength of 25cm in the flow direction (MD) and 2.5cm in the transverse direction (CD) were collected as the tensile strength of the fabric, and the tensile strength in the transverse direction (CD) was 2.5 in the flow direction (MD). Three non-woven test specimens of 25 cm in the transverse direction (CD) were collected and used a tensile tester (Instron Model 5564 manufactured by Instron Japan Ltd.) under the conditions of 200 mm between chucks and 200 mm / min. Tensile tests were performed, and the tensile load was measured on the three test pieces, and the average of the maximum values was taken as the tensile strength.

[0050] (6) Air permeability

Based on JIS L 1096 (Breathability A method), 20 specimens of 100 X 100mm from the sample length direction were collected and measured using a Frazier type tester (Daiei Scientific Instruments Seisakusho AT-360S) Was the air permeability.

[0051] Since the lower the air permeability, the higher the splitting property, it can be determined that the ultrafine fibers are uniformly present throughout the nonwoven fabric.

(A) Propylene polymer part with a load of 2160g, MFR at 230 ° C of 60g / 10min (A) Propylene polymer (density 0 · 910g / cm ³ , melting point 157 ° C, Mw / Mn2.75) (B) High-pressure low-density polyethylene as a high-pressure low-density polyethylene part 2160 g, 190 ° C MFR 20 g / 10 min (B) High-pressure low-density polyethylene (density 0.919 g / cm ³ ) Melting was performed at a temperature of 210 ° C. Using a split-type composite fiber spinning die with a total number of segments of 16 in the cross-sectional shape shown in Fig. 1 (a), the weight ratio of (A) propylene polymer part and (B) high-pressure low-density polyethylene part is 50. / 50 split-type composite continuous fibers were spun by a so-called spunbond method at a yarn speed of 2500 m / min and deposited on a collection belt. Then the fiber In order to divide the fibers, a nozzle with a hole diameter of 0.11 mm is used, the distance from the nozzle to the nonwoven fabric is 10 cm, the first stage water pressure is 60 kgf / cm ² and the second stage water pressure is 100 kgf / cm at a line speed of 5 m / min. ² , the water pressure of the third stage is 100 kgf / cm ² and the water pressure of the fourth stage is 100 kgf / cm ^2. An m ² split fiber nonwoven fabric was prepared. The obtained nonwoven fabric was evaluated by measuring the division ratio, fineness, bending resistance, and tensile strength. The results are shown in Table 1.

[0052] Example 2

(A) Propylene polymer part with a load of 2160g, MFR at 230 ° C of 60g / 10min (A) Propylene polymer (density 0 · 910g / cm ³ , melting point 157 ° C, Mw / Mn2.75) (B) High-pressure method low-density polyethylene part (B) High-pressure method low-density polyethylene (density 0.916 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 35 g / 10 min. Extruder Melts at a molding temperature of 210 ° C, and uses a split type composite fiber spinning die with a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a). (A) Propylene polymer part and (B ) Split type composite continuous fiber with 50/50 weight ratio of high-pressure low-density polyethylene part is spun by the so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collecting belt, and then the fiber Use a nozzle with a hole diameter of Φ0.11 mm to divide the distance from the nozzle to the nonwoven fabric to 10 cm, and the first stage water at a line speed of 5 m / min. In 60 kgf / cm ^2, 2 stage pressure 100 kgf / cm ^2, 3-stage water pressure 100 kgf / cm ^2, 4 stage each 4 times with water pressure 100 kgf / cm ² on the surface and the back surface of the nonwoven fabric, a total of 8 Water jet processing was performed twice to produce a split fiber nonwoven fabric with a basis weight of 50 g / m ² . The obtained nonwoven fabric was evaluated by measuring the division ratio, fineness, bending resistance, and tensile strength. The results are shown in Table 1.

[0053] Example 3

(A) Propylene polymer part with a load of 2160 g, 230 ° C MFR of 60 g / 10 min (A) Propylene polymer (density 0 · 910 g / cm ³ , melting point 161.7 ° C, Mw / Mn3 (B) High-pressure low-density polyethylene part (B) High-pressure method low-density polyethylene part 2160g, 190 ° C MFR 35g / 10 min (B) High-pressure method low-density polyethylene (density 0.916g / cm ³ ) (A) Propylene-based polymer part melted at 210 ° C, using a split composite fiber spinning die with a total number of segments of 16 in the cross-sectional shape shown in Fig. 1 (a) (B) High pressure method In order to spin a split-type composite continuous fiber having a weight ratio of low density polyethylene part 50/50 by a so-called spunbond method at a yarn speed of 2500 m / min, deposit it on a collecting belt, and then split the fiber using a nozzle hole diameter [Phi 0. 11 mm as a 10cm distance from the nozzles to the non-woven fabric, in the first stage pressure 60 kgf / cm ^2, 2-stage water pressure 100 kgf / cm ² at a line speed of 5 m / min, the 3 th stage pressure 100 kgf / cm ^2, 4-stage pressure 100 kgf / cm ² at each four times on the front and back surfaces of the nonwoven fabric is subjected to a total of 8 times of the water jet cutting, dividing basis weight of 50 g / m ² A fiber nonwoven fabric was prepared. The resulting nonwoven fabric was evaluated by measuring the division ratio, fineness, bending resistance, and tensile strength. The results are shown in Table 1.

[0054] Comparative Example 1

(A) Propylene polymer part with a load of 2160 g, 230 ° C MFR of 60 g / 10 min (A) Propylene polymer (density 0.910 g / cm ³ , melting point 157 ° C, Mw / Mn 2.75) Using high-density polyethylene (density: 972 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 16 g / 10 min as a high-density polyethylene part, melt at a separate extruder molding temperature of 240 ° C. (1) The weight ratio of the propylene-based polymer part to the high-density polyethylene part is 50/50. Are spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collection belt, and then a nozzle having a hole diameter of 0.1 lmm is used to divide the fiber. Using a 10cm distance from the nozzle to the non-woven fabric, the first stage water pressure 60kgf / cm ² at the line speed 5m / min, the second stage water pressure 100kgf / c m ^2, and the respective four times on the front and back surfaces of the nonwoven fabric, a total of eight water jet machining performed in the third stage pressure 100 kgf / cm ^2, the fourth-stage pressure 100 kgf / cm ^2, weight per unit area 50 g / An m ² split fiber nonwoven fabric was prepared. The obtained non-woven fabric was evaluated by measuring the division ratio, fineness, stiffness and tensile strength. The results are shown in Table 1.

[0055] Comparative Example 2

(A) Propylene polymer part, load 2160g, 230 ° C MFR 30g / 10min (A) propylene polymer [density 0.910g / cm ³ , melting point 165.4 ° C, Mw / Mn6. 79) as a high-density polyethylene part, high-density polyethylene (density: 972 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 16 g / 10 min, and a separate extruder molding temperature of 240 ° C. so (A) The weight ratio of the propylene-based polymer part to the high-density polyethylene part is 50 //, using a split composite fiber spinning die having a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a). 50 split-type composite long fibers were spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collection belt, and then a nozzle with a hole diameter of 0.11 mm was used to divide the fibers. The distance from the nozzle to the nonwoven fabric is 10 cm, the first stage water pressure is 60 kgf / cm ² at the line speed of 5 m / min, the second stage water pressure is 100 kgf / cm ² , the third stage water pressure is 100 kgf / cm ² , 4 A split fiber nonwoven fabric with a basis weight of 50 g / m ² was produced by applying water jet processing four times each on the front and back surfaces of the nonwoven fabric at a water pressure of 100 kgf / cm ² at the stage. The obtained non-woven fabric was evaluated by measuring the division ratio, fineness, softness and tensile strength. The results are shown in Table 1.

[0056] Comparative Example 3

(A) Propylene polymer part with a load of 2160g, MFR at 230 ° C of 13g / 10min (A) Propylene polymer (density 0.910g / cm ³ , melting point 165.4 ° C, Mw / MnlO 97), high-density polyethylene with a load of 2160 g, 190 ° C MFR of 16 g / 10 min high-density polyethylene (density 0.972 g / cm ³ ), and a separate extruder molding temperature of 240 ° C. (Ii) The weight ratio of the propylene-based polymer part to the high-density polyethylene part is 50, using a split-type composite fiber spinning die having a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a). / 50 split-type composite long fibers are spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collection belt, and then a nozzle with a hole diameter of 0.11 mm is used to split the fibers The distance from the nozzle to the nonwoven fabric is 10 cm, the first stage water pressure is 60 kgf / cm ² at the line speed of 5 m / min, and the second stage water pressure is 100 kgf. In / cm ^2, 3-stage water pressure 100 kgf / cm ^2, 4-stage pressure 100 kgf / cm ² each four times on the front and back surfaces of the nonwoven fabric is subjected to water jet machining of the total of 8 times, basis weight A 50 g / m ² split fiber nonwoven fabric was produced. The obtained non-woven fabric was evaluated by measuring the division ratio, fineness, softness and tensile strength. The results are shown in Table 1.

[0057] Comparative Example 4

(A) Propylene polymer part with a load of 2160 g, 230 ° C MFR of 30 g / 10 min (A) Propylene polymer (density 0 · 910 g / cm ³ , melting point 157 ° C, Mw / Mn2.80) (B) (B) High pressure method low density polyethylene (density 0.919 g / cm ³ ) was used as the high pressure method low density polyethylene part with a load of 2160 g and 190 ° C MFR of 20 g / 10 min. (A) Propylene polymer part and (B) High-pressure low-density polyethylene using a split-type composite fiber spinning die having a total number of segments of 16 in the cross-sectional shape shown in Fig. 1 (a). A split type composite continuous fiber having a weight ratio of 50/50 is spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collecting belt, and then the pore diameter Φ is used to split the fiber. 0.1 Using a 11mm nozzle, the distance from the nozzle to the nonwoven fabric is 10cm, the first stage water pressure 60kgf / cm ² at the line speed 5m / min, the second stage water pressure 100kgf / cm ² and the third stage water pressure 100kgf / cm ^2, 4-stage of each four times with water pressure 100kgf / cm ² on the front and back surfaces of the non-woven cloth, a total of 8 times of water Subjected to jet machining, basis weight was produced of the split fiber nonwoven fabric 50 g / m ^2. The obtained nonwoven fabric was evaluated by measuring the division ratio, fineness, bending resistance, and tensile strength. The results are shown in Table 1.

[0058] Comparative Example 5

(A) Propylene polymer part with a load of 2160 g, 230 ° C MFR of 60 g / 10 min (A) Propylene polymer (density 0.910 g / cm ³ , melting point 157 ° C, Mw / Mn 2.75) Using high-density polyethylene (density 0.95 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 30 g / 10 min as a high-density polyethylene part, melted at 210 ° C at a separate extruder molding temperature. Then, using a split type composite fiber spinning die having a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a), the weight of (i) propylene polymer part and (ii) high pressure method low density polyethylene part A split type composite continuous fiber having a quantity ratio of 50/50 is spun by a so-called span bond method at a yarn speed of 2500 m / min, deposited on a collection belt, and then has a pore diameter of 0.11 mm for fiber splitting. use nozzle from the nozzle as 10cm the distance to the nonwoven fabric, line 1 stage at a speed of 5 m / min pressure 60 kgf / cm ^2, 2 stage of In pressure 100 kgf / cm ^2, 3-stage water pressure 100 kgf / cm ^2, 4-stage pressure lOOkgf / cm ² each four times on the front and back surfaces of the nonwoven fabric is subjected to a total of eight water jet machining, basis weight A 50 g / m ² split fiber nonwoven fabric was produced. The obtained nonwoven fabric was evaluated by measuring the division ratio, fineness, stiffness and tensile strength. The results are shown in Table 1.

[0059] Comparative Example 6 (A) Propylene polymer part with a load of 2160 g, 230 ° C MFR of 60 g / 10 min (A) Propylene polymer (density 0.910 g / cm ³ , melting point 157 ° C, Mw / Mn 2.75) As the polyethylene part, linear low-density polyethylene (density: 915 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 15 g / 10 min was used. (Ii) Propylene-based polymer part and (ii) High-pressure low-density polyethylene part using split-type composite fiber spinning die with a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a) A split-type composite continuous fiber having a weight ratio of 50/50 is spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collecting belt, and then has a pore diameter of φ 0. Using a 11 mm nozzle, the distance from the nozzle to the nonwoven fabric is 10 cm, the first stage water pressure is 60 kgf / cm ² at the line speed of 5 m / min, the second stage With a water pressure of 100 kgf / cm ² , a third-stage water pressure of 100 kgf / cm ² , and a fourth-stage water pressure of 100 kgf / cm ² , four times each on the front and back surfaces of the nonwoven fabric, a total of 8 times of water jet processing, and the basis weight is A 50 g / m ² split fiber nonwoven fabric was prepared. The obtained non-woven fabric was evaluated by measuring the division ratio, fineness, stiffness and tensile strength. The results are shown in Table 1.

Comparative Example 7

(A) Propylene polymer part, load 2160g, 230 ° C MFR 35g / 10min (A) propylene polymer [density 0.910g / cm ³ , melting point 157 ° C, Mw / Mn2.7] Using high-density polyethylene (density: 0.972 g / cm ³ ) with a load of 2160 g and 190 ° C MFR of 16 g / 10 min as a high-density polyethylene part, melt at a separate extruder molding temperature of 240 ° C. However, a split type composite fiber spinning die having a total number of segments of 16 in the cross-sectional shape as shown in Fig. 1 (a) was used. (Ii) The weight ratio of the propylene polymer part to the high density polyethylene part was 50/50. Are spun by a so-called spunbond method at a yarn speed of 2500 m / min, deposited on a collection belt, and then a nozzle having a hole diameter of 0.11 mm is used to divide the fiber. The distance from the nozzle to the non-woven fabric is 10 cm, the first stage water pressure is 60 kgf / cm ² and the second stage water pressure is 100 kgf / cm at a line speed of 5 m / min. ² , the water pressure of the third stage is 10 Okgf / cm ² , the water pressure of the fourth stage is 100 kgf / cm ² , 4 times each on the front and back surfaces of the nonwoven fabric, total 8 times water jet processing, the basis weight is 50g / m ^Two split fiber nonwoven fabrics were prepared. About the obtained nonwoven fabric, the division ratio, the fineness, the bending resistance, and the tensile strength were measured and evaluated. The results are shown in Table 1.

[table 1]

table 1

[0062] As is clear from Table 1, the composite long fiber nonwoven fabrics using the polypropylene and polyethylene of Example 1, Example 2, and Example 3 can be easily divided into 80% or more, and thus obtained. The fineness of the resulting split fiber is also thin, and it is extremely excellent in flexibility and texture!

[0063] In contrast, the composite long fiber nonwoven fabric using polypropylene and polyethylene of Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, Comparative Example 5, Comparative Example 5, Comparative Example 6, and Comparative Example 7 is difficult to divide. The fineness could not be reduced, and the flexibility and texture were poor.

Industrial applicability

[0064] The split-type composite fiber nonwoven fabric obtained by the method for producing a split fiber nonwoven fabric of the present invention is extremely excellent in flexibility and texture, and various wiping cloths, surgical garments, medical gowns, and industrial gowns. It can also be widely used for non-woven fabrics for clothing, packaging fabrics, surface materials for sanitary materials such as disposable ommu and napkins, bedding such as bed sheets and pillow covers, carpets and base fabrics for artificial leather.

[0065] Other applications include, for example, VTR and compact 'disk cleaning cloth, disk polishing, filter cloth, filter, battery separator, general consumer materials such as glass, precious metal, high-quality furniture, window glass, OA equipment, Examples include automobile windows, musical instruments, mirrors, dirt removal, oil flooring, flooring, and toilet cleaners.

Claims

The scope of the claims

[1] (A) Propylene polymer having a load of 2160 g, MFR force at 230 ° C of 0 g / 10 min or more, and

(B) using high pressure method low density polyethylene,

Split type composite long fiber in which the resin part made of (A) and the resin part made of (B) are in contact with each other

Yes

[2] (A) Mw / Mn (weight-average molecular weight / number-average molecular weight ratio) of the propylene polymer is 5.

2. The split-type composite continuous fiber according to claim 1, which is less than 0.

[3] The split type composite continuous fiber according to claim 1, wherein (B) high-pressure low-density polyethylene has a load of 2160 g and an MFR force of S20 g / 10 min.

[4] A non-woven fabric having a split-type composite continuous fiber strength according to claim 1 or 2.

[5] A split fiber nonwoven fabric obtained by splitting (A) a propylene-based polymer portion and (B) a high-pressure method low-density polyethylene portion of a split-type composite long fiber by applying stress to the nonwoven fabric according to claim 4. .

6. The split fiber nonwoven fabric according to claim 5, wherein the stress is applied using a high-pressure liquid flow.

[7] (A) Propylene polymer having a load of 2160 g and MFR at 230 ° C of 40 g / 10 min or more and (B) high-pressure low-density polyethylene are discharged from a spinneret having a composite spinning nozzle. The composite long fiber (A) propylene polymer part and (B) high-density low-density polyethylene part that are spun together is cooled by a cooling fluid, and tension is applied to the long fiber to reduce the length. (A) A method for producing a nonwoven fabric comprising split-type composite continuous fibers, wherein the propylene-based polymer portion is oriented and crystallized and then collected and deposited on a collection belt.

[8] The nonwoven fabric according to claim 4, wherein stress is applied to divide the (A) propylene-based polymer portion and (B) the high-pressure low-density polyethylene portion of the split-type composite continuous fiber, A method for producing a split fiber nonwoven fabric.

[9] The method for producing a split fiber nonwoven fabric according to [8], wherein the stress is applied using a high-pressure liquid flow.