JP2007009403A - Nonwoven fabric comprising mixed fiber and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonwoven fabric having properties of both a polyolefin and an elastomer and excellent in touch feeling and stretchability. <P>SOLUTION: The nonwoven fabric comprises mixed fiber which comprises fibers comprising a polyolefin and fibers comprising an elastomer and is produced by simultaneously extruding different molten polymers comprising the polyolefin and the elastomer from different nozzles set on the same dye, and the method for producing the nonwoven fabric is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a nonwoven fabric in which fibers made of polyolefin and fibers made of elastomer are finely dispersed and mixed, and a method for producing the same.

  In recent years, non-woven fabrics have been used for various purposes, and improvements in various properties are required depending on the uses. For example, non-woven fabrics used for sanitary materials such as disposable diapers and sanitary napkins, and base materials for poultices are required to have good tactile sensation, water resistance and excellent moisture permeability. In addition, stretchability is also required depending on the location used. Furthermore, heat-sealability is required between the non-woven fabric materials that constitute sanitary materials and the like during bonding.

  These properties are difficult to achieve with a nonwoven fabric composed of fibers made of a single polymer. For example, a spunbond nonwoven fabric composed of bicomponent fibers in order to obtain a nonwoven fabric having both strength and flexibility, In addition, in order to improve water resistance, a melt blown nonwoven fabric is laminated. Moreover, in order to make a non-woven fabric that has stretchability and excellent tactile sensation, a stretchable non-woven fabric is laminated on a non-woven fabric made of a stretchable material. And in order to laminate a nonwoven fabric, it had to be made into the combination of the material excellent in interlayer adhesiveness. Furthermore, in order to heat-seal non-woven fabrics made of different types of polymers, a bonding process using hot melt or the like that complicates processing is required.

In addition, in order to make a nonwoven fabric having both characteristics of different materials, a method of laminating a long-fiber nonwoven fabric layer made of different polymers and performing mechanical entanglement such as water jet or needle punch, Alternatively, there is a method of performing chemical bonding using an adhesive. In the mechanical entanglement method, the productivity is lowered, and there is no practicality with respect to the low weight per unit area (30 g / m ² or less) required for absorbent articles such as diapers, such as strength and fuzz of the obtained web. The chemical bond method has a problem of complicated processing.

  An object of this invention is to provide the nonwoven fabric which has the characteristics which polyolefins and an elastomer have, which is good in touch and excellent in stretchability.

  According to the present invention, different types of molten polymers made of polyolefins and elastomers are simultaneously extruded from different nozzles arranged on the same die, melt-spun, and mixed with fibers made of polyolefins and fibers made of elastomers. A nonwoven fabric made of fibers is provided.

  In the present invention, the polyolefin is preferably at least one selected from polyethylene and polypropylene.

  In the present invention, the elastomer is preferably at least one selected from polyolefin elastomers, polystyrene elastomers, polyester elastomers, polyamide elastomers and polyurethanes.

  In the present invention, it is preferable that the mixed fiber is melt-spun by a spunbond method.

  In the present invention, it is preferable that the mixed fiber is melt-spun by a melt blow method.

  According to the present invention, different types of molten polymers made of polyolefins and elastomers are simultaneously extruded from different nozzles arranged on the same die, melt-spun, and mixed fibers obtained by mixing fibers made of polyolefins and fibers made of elastomers. The manufacturing method of the nonwoven fabric which becomes is provided.

  Moreover, the laminated body which has at least 1 layer of the nonwoven fabric which consists of said mixed fiber is provided by this invention.

  Since the nonwoven fabric made of the mixed fiber of the present invention is a nonwoven fabric having the characteristics of polyolefins and elastomers, a single layer nonwoven fabric having good tactile sensation and excellent stretchability can be obtained. In the laminate in which the nonwoven fabric composed of the mixed fibers of the present invention is laminated, a nonwoven fabric layer having the characteristics of polyolefins and elastomers intervenes, so flexibility, water resistance, interlayer adhesion, etc. than conventional ones A laminated nonwoven fabric excellent in the above can be obtained. According to the method for producing a nonwoven fabric composed of the mixed fibers of the present invention, since the fibers composed of polyolefins and the fibers composed of elastomers are finely dispersed and mixed, it has the characteristics of polyolefins and elastomers. A nonwoven fabric can be obtained.

The nonwoven fabric consisting of the mixed fibers according to the present invention, the production method thereof, and the laminate comprising the nonwoven fabric will be specifically described.
The mixed fiber used in the nonwoven fabric of the present invention is a fiber in which different types of molten polymers are simultaneously extruded and melt-spun from different nozzles arranged on the same die, and fibers made of different types of polymers are mixed.

  In the present invention, the different polymer is a combination of polyolefins such as polyethylene and polypropylene, and elastomers such as polyolefin elastomer, polystyrene elastomer, polyester elastomer polyamide elastomer and polyurethane.

The mixed fiber is preferably obtained by melt spinning by a spunbond method. The mixed fiber is preferably obtained by melt spinning by a melt blow method. Each will be described below.
In the production of mixed fibers by the spunbond method, two kinds of polymers selected from polyolefins and elastomers are melted by separate extruders or the like. The melted polymer is guided to the same die, discharged from a number of nozzles provided on the die, and spun. The two types of polymers are discharged from different nozzles disposed on the die. At this time, if two types of polymer discharge nozzles are arranged as shown in FIG. 2, for example, the mixed state and ratio of the two types of fibers can be freely controlled. The filament discharged from the nozzle is cooled and stretched by a high-speed air flow, and deposited on a collecting conveyor to form a nonwoven web.

  The nonwoven web is then entangled to obtain a spunbond nonwoven. Examples of the entanglement treatment method include heat embossing using an embossing roll, ultrasonic fusion, entanglement using a water jet, fiber fusion using hot air through, and entanglement using a needle punch.

  In the production of mixed fibers by the melt blow method, two kinds of polymers selected from polyolefins and elastomers are melted by separate extruders or the like. The melted polymer is guided to the same melt blow die, and discharged from two or more nozzles arranged in a row in the die into two converging high-speed heated air streams of air to be spun. The two types of polymers are discharged from different nozzles disposed on the die. At this time, if two types of polymer discharge nozzles are arranged as shown in FIG. 4, for example, the mixed state and ratio of the two types of fibers can be freely controlled. Microfibers discharged from the nozzle are deposited on a collection screen to obtain a melt blown nonwoven fabric. Also in the case of a melt blown nonwoven fabric, an entanglement process may be performed in a subsequent process, if necessary.

  If a non-woven fabric made of mixed fibers using polyethylene or polypropylene as an extensible material and an elastomer as an elastic material is produced, a single-layer non-woven fabric having excellent elasticity can be obtained.

  Thus, the nonwoven fabric of this invention can obtain the single layer nonwoven fabric and laminated body which have the characteristic which was not obtained conventionally. And the freedom degree with respect to the combination of a raw material with good interlayer adhesiveness of a laminated body also increases, and, thereby, the expansion of the use of a nonwoven fabric is anticipated.

  Hereinafter, the present invention will be described with reference to examples. Measurement of elongation at break and strain after 100% elongation used in Examples and Comparative Examples were performed by the following methods.

(1) Elongation at break According to JIS L1906, a test piece having a width of 50 mm and a length of 200 mm was measured with a tensile tester at a room temperature, a chuck interval of 100 mm, and a tensile speed of 100 mm / min.
(2) Strain after 100% elongation After pulling under the same conditions as in the tensile test of (1) above, stretching to 100% elongation, returning at the same speed, the strain when the stress becomes zero is strained. As sought.

Example 1
MFR (according to ASTM D1238, temperature 230 ° C., measured at load 2.16 kg) 60 g / 10 min, density 0.91 g / cm ³ , melting point 160 ° C. 95 parts by weight of propylene homopolymer, MFR (according to ASTM D1238, temperature 190 SEBS (styrene / ethylene / butylene / styrene block copolymer) and a mixture of 5 parts by weight of high density polyethylene having a density of 0.97 g / cm ³ and a melting point of 134 ° C. Asahi Kasei's Tuftec ^™ 1052), from different nozzles arranged in the same die, fiber A and fiber B were respectively made by the spunbond method with both resin temperature and die temperature of 200 ° C., cooling air temperature Melt spinning was performed at 20 ° C. and a drawing air speed of 4000 m / min.

At that time, the nozzle arrangement pattern of the fibers A and B of the spinneret is FIG. 2B (the nozzle pitch is 8 mm in the vertical direction and 9 mm in the horizontal direction), the nozzle diameter is 0.6 mmφ, and the ratio of the number of nozzles is the fiber A : Fiber B = 3: 1, single hole discharge rate of fiber A 0.6 g / min / hole, single hole discharge rate of fiber B 0.8 g / min / hole. From the average value of the filament diameters obtained, the fiber speed was 1500 m / min for fiber A and 800 m / min for fiber B. The web former speed is 30 m / min, and embossing is performed at 120 ° C. (embossing area ratio: 7%, marking pitch: vertical and horizontal directions 2.1 mm, stamping shape: rhombus), and the basis weight is 30 g / m ² . A spunbond nonwoven was produced. Table 1 shows the measurement results of the obtained spunbonded nonwoven fabric.

(Comparative example)
A span with a weight per unit area of 28 g / m ² was obtained in the same manner as in Example 1 except that no fiber was used and a SEB raw material was used, and a mixture of 95 parts by weight of propylene homopolymer and 5 parts by weight of high-density polyethylene was used. A bonded nonwoven fabric was produced. Table 1 shows the measurement results of the obtained spunbonded nonwoven fabric.

実施例のスパンボンド不織布は、積層によらないでも十分な伸縮性を示した。

The spunbonded nonwoven fabric of the example exhibited sufficient stretchability even without lamination.

It is the schematic which shows an example of the spun bond nonwoven fabric manufacturing apparatus for manufacturing the nonwoven fabric consisting of the mixed fiber which concerns on this invention. It is the example of a partial figure of the pattern arrangement | positioning figure of the spun bond nonwoven fabric manufacturing nozzle for manufacturing the nonwoven fabric consisting of the mixed fiber which concerns on this invention. It is the schematic which shows an example of the melt blown nonwoven fabric manufacturing apparatus for manufacturing the nonwoven fabric consisting of the mixed fiber which concerns on this invention. An example (a) of a cross-sectional view of a spinneret for producing a melt blown nonwoven fabric for producing a nonwoven fabric composed of mixed fibers according to the present invention, and an example (b) of a partial plan view of a spinneret nozzle portion viewed from below ( c).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 1 'Extruder for polymers different from 1 2 Spinneret 3 Continuous filament 4 Cooling air 5 Ejector 6 Collection device 7 Suction 8 Web 9 Entangling process 10 Winding roll 11 Spunbond nonwoven melt spinning polymer nozzle 12 11 Nozzle of spunbonded nonwoven fabric different from 11 13 Extruder 13 ′ Extruder for polymer different from 13 13 High-pressure heated air inlet 15 Spinner cap 16 Microfiber 17 Collection device 18 Web 19 Melted polymer Different melt polymer inlets 21 19 Manifold 22 Air holder 23 Air flow 24 Microfiber 25 Melt blown nonwoven melt spinning polymer nozzle 26 25 Different melt blown nonwoven melt spinning polymer nozzle

Claims (5)

A non-woven fabric made of mixed fibers in which different types of molten polymers are simultaneously extruded from different nozzles arranged on the same die and melt-spun, and fibers made of different types of polymers are mixed. The nonwoven fabric comprising the mixed fiber according to claim 1, wherein the mixed fiber is melt-spun by a spunbond method. The nonwoven fabric comprising the mixed fiber according to claim 1, wherein the mixed fiber is melt-spun by a melt blow method. A method for producing a nonwoven fabric comprising mixed fibers obtained by simultaneously extruding and spinning different types of molten polymers from different nozzles arranged on the same die, and mixing fibers made of different types of polymers. The laminated body which has at least 1 layer of the nonwoven fabric which consists of mixed fiber in any one of Claims 1-3.

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