JPH06158507A - Perforated interlaced ultra-fine fiber nonwoven fabric and its production - Google Patents

Abstract

PURPOSE:To obtain nonwoven fabric, excellent in mechanical characteristics, dimensional stability and flexibility and suitable for uses as various sanitary materials, industrial materials and clothes. CONSTITUTION:This perforated interlaced ultra-fine fiber nonwoven fabric is constructed of ultra-fine fiber having 0.1-10mum average fiber diameter and has sites where the constituent fibers are mutually and three-dimensionally interlaced and sites having openings in a mixed state. This nonwoven fabric has characteristics of 20-50% average opening ratio and <=0.3g/g/m<2> compression rigidity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a perforated ultrafine fiber nonwoven fabric having entanglement excellent in mechanical properties, dimensional stability and flexibility, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, a so-called melt blown method has been well known in which a polymer is discharged from a die and simultaneously pulled and thinned by a high temperature and high speed gas to obtain ultrafine fibers. For example, Industrial and Engineering Chemistry, Vol. 48, No. 8 (P1342-1346, published in 1956) discloses a basic method and apparatus of the melt blown method, and it is currently possible to obtain extremely fine fibers. ,
It is developed with various materials.

Further, a fiber-forming resin is melt-spun and a melt blown method is applied to obtain an ultrafine fiber non-woven fabric, and the non-woven fabric is partially thermocompressed by using a hot embossing roller to obtain mechanical properties and dimensional stability. The method of improving the sex is also widely adopted. However, although the ultrafine fiber nonwoven fabric obtained by this method has improved mechanical properties, it has a drawback that flexibility is impaired due to partial thermocompression bonding.

Also, Japanese Patent Publication No. 58-43502 and Japanese Patent Publication No. 4-3
In 3905, using a support plate having a large number of mold holes,
A method is disclosed in which a web is deposited on the support plate and a water flow is applied from above the web to produce a nonwoven fabric having openings. However, the method for producing a web used to produce this nonwoven fabric is a method in which short fibers are suspended in water, a method for papermaking, a method for webbing staple fibers with a card, etc. As is clear from the figure, it is at most 1.5 d or 2 d. Therefore, since it is not a nonwoven fabric composed of ultrafine fibers as the object of the present invention, it is inferior in flexibility.

[0005]

The present invention solves the above-mentioned problems and is excellent in mechanical properties such as tensile strength and tensile elongation, dimensional stability and flexibility, and is used for various sanitary materials and industrial materials. It is a technical object to provide an apertured ultrafine fiber nonwoven fabric which can be suitably used not only for clothing, but also to provide a method for producing the same.

[0006]

The present inventors have arrived at the present invention as a result of extensive studies to solve the above problems. That is, the present invention has the following configurations. (1) A non-woven fabric composed of ultrafine fibers with an average fiber diameter of 0.1 to 10 μm, where the constituent fibers are three-dimensionally entangled with each other and the parts having openings are mixed. The average porosity is 20 to 50%, and the compression stiffness is 0.3 g / g.
/ M ² or less, an open pore entangled ultrafine fiber nonwoven fabric. (2) The fiber-forming resin is melt-spun and the spinning temperature is 20 to 50
℃ at a high temperature and with a high-speed gas with a pressure of 1.0 to 2.5 Kg / cm ² , tow and deposit it as a web on a moving net, and then transfer the web onto a wire mesh of 10 to 50 mesh to obtain a high pressure liquid. A method for producing an open-hole entangled ultrafine fiber nonwoven fabric, characterized in that the constituent fibers are three-dimensionally entangled with each other and a hole is generated by applying a flow.

The present invention will be described in detail below. First, in the present invention, in order to impart sufficient flexibility to the non-woven fabric, it is necessary that the fibers constituting the non-woven fabric are ultrafine fibers and the average fiber diameter of the ultrafine fibers is 0.1 to 10 μm. Ultrafine fibers with an average fiber diameter of less than 0.1 μm have poor spinnability.
When it exceeds 10 μm, it is difficult to obtain a nonwoven fabric having a high flexibility, which is not preferable.

Further, in the nonwoven fabric of the present invention, it is necessary that the part where the constituent fibers are three-dimensionally entangled and the open part are mixed. Since the constituent fibers are three-dimensionally entangled, mechanical properties and dimensional stability can be improved even if there is no thermocompression bonding site. In addition, the perforation provides a nonwoven fabric that is highly flexible and breathable.

The open pore entangled ultrafine fiber nonwoven fabric of the present invention preferably has an average open area ratio of 20 to 50%. Average porosity is 20
If it is lower than 50%, the open area is insufficient and the flexibility and breathability are poor, which is not preferable. On the contrary, if it exceeds 50%, the area of the open area is too large and the texture is poor. It is not preferable because the characteristics are deteriorated and the practicality is lacking.

Further, in order to impart sufficient flexibility to the nonwoven fabric of the present invention, it is necessary to set the compression stiffness to 0.3 g / g / m ² or less. Compression stiffness is 0.3 g / g / m ²
If it exceeds, the nonwoven fabric becomes hard, which is not preferable.

As the fiber-forming resin forming the nonwoven fabric of the present invention, thermoplastic resins such as polyolefin-based polymers, polyamide-based polymers and polyester-based polymers can be used.

The fiber-forming polyolefin polymer applicable to the present invention includes aliphatic α-monoolefins having 2 to 18 carbon atoms, such as ethylene, propylene, 1-
There are homopolymers or copolymers of butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, 1-dodecene, 1-octadecene. Aliphatic α-monoolefins are other olefins and / or small amounts (up to about 10% by weight of the polymer) of other ethylenically unsaturated monomers such as butadiene, isoprene, 1,3-pentadiene, styrene, α-methyl. It may be copolymerized with a similar ethylenically unsaturated monomer such as styrene. Especially in the case of polyethylene, up to about 10% by weight of polymer propylene, 1-
Copolymers with butene, 1-hexene, 1-octene or similar higher α-olefins are preferred.

Fiber forming polyamide polymers applicable to the present invention include nylon 4, nylon 46, nylon 6, nylon 66, nylon 610, nylon 11 and nylon.
12 and polymeta-xylylene adipamide (MXD6), poly-para-xylylene decanamide (PXD12), polybiscyclohexylmethane decanamide (PCM12) or copolymers having these monomers as constituent units.

Examples of the fiber-forming polyester polymer applicable to the present invention include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid and naphthalene-2,6-dicarboxylic acid as acid components, or adipic acid and sebacine. Synthesized from aliphatic dicarboxylic acids such as acids or esters thereof and diol compounds such as ethylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, cyclohexane-1,4-dimethanol as alcohol components It is a homopolymer or a copolymer, and paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, polyalkylene glycol, pentaerythritol, bisphenol A, etc. may be copolymerized with the above polyester.

In the present invention, the above thermoplastic resins may be mixed and used within a range that does not impair the spinnability. For example, two different polyamide polymers may be mixed, or a polyester polymer and a polyolefin polymer may be mixed and used. Especially in the latter case, it is effective in suppressing the shrinkage of unoriented and low-crystallized polyester. Further, the above-mentioned thermoplastic polymer is an optional additive such as a matting agent, a pigment, a flameproofing agent, a deodorant, an antistatic agent, an antioxidant, and an ultraviolet absorber within a range that does not impair the effects of the present invention. May be added.

Next, a method for manufacturing the open-entangled ultrafine fiber nonwoven fabric will be described. First, the above-mentioned fiber-forming resin is melt-spun, blown with a high-speed gas at a high temperature, pulled and thinned to form ultrafine fibers, and a web is prepared by a meltblown method in which the ultrafine fibers are deposited on a moving net. Next, this web is transferred onto a wire mesh and a high-pressure liquid flow is jetted to three-dimensionally entangle the fibers constituting the web and to form openings. Excess water in the obtained non-woven fabric is removed by mechanical squeezing, followed by drying and heat treatment to obtain a final product.

In the present invention, the fiber-forming resin is melt-spun and drawn by a high-speed gas at a temperature of 20 to 50 ° C. higher than the spinning temperature and a pressure of 1.0 to 2.5 Kg / cm ² to form a web. There is a need. When the gas temperature or pressure is lower than the range of the present invention, when the fiber-forming resin is a highly crystalline polymer, it is not sufficiently thinned, and ultrafine fibers cannot be obtained. On the contrary, when the temperature or pressure of the gas is higher than the range of the present invention, the mechanical properties of the obtained nonwoven fabric are deteriorated, or the discharged yarn is blown off by the gas to shorten the fiber length, and the mechanical properties of the obtained nonwoven fabric are reduced. Is deteriorated and it is not practical, which is not preferable.

As described above, the fiber-forming resin is melt-spun and the ultrafine fibers obtained by pulling and thinning with a high-temperature high-speed gas are deposited on the moving net below to form a web. When the distance between the mouthpiece and the net is reduced, the degree of freedom of the yarn discharged from the mouthpiece is reduced, and the degree of entanglement can be reduced. Conversely, when the distance between the mouthpiece and the net is increased, the yarn is discharged from the mouthpiece. The degree of freedom of the yarn is increased, and the degree of entanglement can be increased.

In the present invention, the web obtained by the melt blown method is transferred onto a wire net and a high-pressure liquid stream is jetted onto the web to form three-dimensional entanglement and openings. The degree of entanglement can be easily adjusted by the distance between the die and the net when forming the web, and the conditions for applying the high-pressure liquid flow.

The wire mesh used for moving the web obtained by the melt blown method to act the high-pressure liquid flow is 10 to
It should be 50 mesh, preferably 15-45 mesh, more preferably 20-40 mesh. When a wire mesh of less than 10 mesh is used, the area of the openings is too large, resulting in a non-woven fabric having a poor texture and poor mechanical properties, so that it cannot be used. On the other hand, if the wire mesh exceeds 50 mesh, the area of the pores of the obtained nonwoven fabric is too small, and thus sufficient air permeability and flexibility cannot be imparted.

In the present invention, a high-pressure liquid stream is applied to the web obtained by the melt blown method, and the impact force of the high-pressure liquid stream releases the partially fused fibers between the webs.
Since the constituent fibers are three-dimensionally entangled with each other and the openings are formed, the resulting nonwoven fabric has a compression stiffness of 0.3 g / g /
Since it becomes m ² or less, sufficient flexibility can be imparted to the nonwoven fabric.

The high-pressure liquid stream used in the present invention can be obtained by injecting liquid at high pressure through the injection holes. The injection holes generally have a hole diameter of 0.05 to 1.0 mm, and preferably 0.1 to 0.4 mm. The injection pressure is preferably about 5 to 150 Kg / cm ² . The liquid used is not particularly limited, but water or warm water that is easy to handle is preferable.

When the high-pressure liquid stream is jetted onto the web, the distance between the jet holes and the web is preferably about 1 to 15 cm. If this distance exceeds 15 cm, the impact force exerted by the liquid on the web decreases, and the entanglement between fibers becomes insufficient, making it difficult to impart flexibility to the nonwoven fabric. On the other hand, if it is less than 1 cm, the impact force of the liquid exerted on the web increases, and the texture of the web tends to be disturbed.

In the present invention, it is preferable to provide a plurality of injection holes for the high-pressure liquid stream and arrange them in rows in a direction perpendicular to the direction of travel of the web. In order to obtain a uniform and close entangled bond, it is preferable to inject the high-pressure liquid stream from both sides of the web, but when injecting from only one side, the injection treatment of the high-pressure liquid stream is performed in two or more rows, preferably three or more rows. It is good to do it in. The liquid injection pressure is low in the previous stage and high in the latter stage.
It is preferable for making the texture of the non-woven fabric uniform.

Further, according to the present invention, by appropriately selecting the number of meshes of the wire mesh used when the high pressure liquid flow is made to act, or the weave structure of the wire mesh, the pattern formed in the opening portion of the obtained nonwoven fabric can be arbitrarily set. Can be changed.

The non-woven fabric subjected to the entanglement treatment with the high-pressure liquid stream is then subjected to mechanical squeezing to remove excess moisture, and then dried and heat-treated to obtain a final product. It is possible to select not only the removal but also an appropriate shrinkage, and the heat treatment method may be either dry heat treatment or wet heat treatment. In the present invention, the web formation and the entanglement treatment by the high-pressure liquid flow are preferably continuous steps, but they may be separate steps.

[0027]

EXAMPLES Next, the present invention will be specifically described with reference to examples. The various characteristic values in the examples were measured by the following methods. Melting point: Differential scanning calorimeter DSC-manufactured by Perkin Elma
The melting point was defined as the temperature at which the exothermic value of the melting endotherm curve measured using a type 2 and a temperature rising rate of 20 ° C./min. -Polypropylene melt flow rate value: ASTM-
It was measured by the method described in D1238 (L). (Hereinafter, simply referred to as MFR) -Relative viscosity of polyethylene terephthalate: 0.5 g using a mixed solvent of phenol and ethane tetrachloride in a 1/1 weight ratio.
The polymer concentration was adjusted to / 100 cc and the temperature was measured at 20 ° C. -Relative viscosity of nylon 6: 1 g of the resin was dissolved in 100 ml of 96% sulfuric acid, and the viscosity was measured at 25 ° C by an ordinary method. -Average fiber diameter: The fibers forming the nonwoven fabric were measured with an electron microscope. Tensile strength of non-woven fabric: Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd. was used and 10 sample pieces having a width of 5 cm and a length of 10 cm were prepared and pulled according to the strip method described in JIS-L-1096. The maximum tensile strength was individually measured at a speed of 10 cm / min, and the average value was calculated. -Nonwoven fabric tensile elongation: The elongation at maximum tensile strength measured by the above method was determined.・ Compressive bending resistance: Prepare 5 sample pieces with a width of 5 cm and a length of 10 cm, bend each sample piece laterally into a cylindrical shape, and join the ends to form a sample. Using Tensilon UTM-4-1-100 manufactured by the company, compression speed 5c
The sample was compressed in the longitudinal direction under the condition of m / min, the stress at the maximum load was measured, and the average value was divided by the basis weight to obtain the value. -Aperture ratio: Ten sample pieces of 1 inch square were prepared, 20 aperture parts were randomly selected by a projector, and the average value obtained by calculating the area was determined as the aperture ratio.

Example 1 Polypropylene having a melting point of 160 ° C. and an MFR of 400 was spun at a spinning temperature.
Melt spinning at 280 ℃, single hole discharge 0.2 g / min, temperature 320
It was pulled by heated air having a pressure of 1.4 kg / cm ² at ℃. The obtained yarn is collected and deposited on a net moving at a speed of 6.7 m / min at a position 20 cm away from the spinneret to form a web, which is then fed onto a 20-mesh wire net and is then applied by a water applicator. After applying water, a high-pressure liquid stream was jetted to perform an open hole entanglement treatment. High pressure liquid flow has a hole diameter of 0.12 mm and hole pitch
It was a high-pressure water columnar flow that was sprayed at a water pressure of 30 kg / cm ² with 0.6 mm and 3 rows of injection holes, and was treated twice on one side of the web from a position 8 cm above the web. Further, the water content was squeezed with a mangle roll, and dried with a drier at 98 ° C. to obtain an aperture-entangled ultrafine fiber nonwoven fabric.

Example 2 The web obtained under the same conditions as in Example 1 was fed onto a 40-mesh wire net and water was applied by a water applicator, followed by a water pressure of 30 k.
A high-pressure columnar flow of g / cm ² was applied to obtain a nonwoven fabric under the same conditions as in Example 1.

Example 3 A web obtained under the same conditions as in Example 1 except that the web was collected and deposited on a net moving at a speed of 4 m / min to give 20
After supplying it on the wire mesh of the mesh and applying water with the water application device, a high-pressure water columnar flow with a water pressure of 30 kg / cm ² is applied,
A nonwoven fabric was obtained under the same conditions as in Example 1.

Example 4 Nylon 6 having a melting point of 214 ° C. and a relative viscosity of 2.4 was prepared at a spinning temperature of 32.
Melt-spin at 0 ℃, single hole discharge 0.2g / min, temperature 350
It was pulled by heated air having a pressure of 1.6 kg / cm ² at ℃. The obtained yarn is collected and deposited on a net moving at a speed of 6.7 m / min at a position 25 cm away from the spinneret to form a web, which is then fed onto a 20-mesh wire net and is then applied by a water applicator. After applying water, a high-pressure liquid stream was jetted to perform an open hole entanglement treatment. High pressure liquid flow has a hole diameter of 0.12 mm and hole pitch
It was a high-pressure water columnar flow that was sprayed at a water pressure of 40 kg / cm ² in a row of injection holes of 0.6 mm in three groups, and was treated twice on one side of the web from a position 8 cm above the web. Further, the water was squeezed with a mangle roll and dried with a drier at 98 ° C to obtain a nonwoven fabric.

Example 5 Polyethylene terephthalate having a melting point of 260 ° C. and a relative viscosity of 1.24 and polypropylene having an MFR of 400 were blended at a weight ratio of 90/10, and the spinning temperature was 350 ° C. and the single hole discharge rate was 0.2.
Melt spinning at g / min, temperature 380 ℃, pressure 1.2 kg / cm
Pulled with ² heated air. 15c of the obtained thread from the spinneret
A web is collected and deposited on a net moving at a speed of 6.7 m / min at a distance of m, and then this web is supplied onto a 20-mesh wire net and water is applied by a water applicator, and then a high pressure liquid is applied. A flow was jetted to perform an open hole confounding process. The high-pressure liquid flow is a high-pressure water column flow injected with a hole diameter of 0.12 mm, a hole pitch of 0.6 mm, three rows of injection holes, and a water pressure of 50 kg / cm ² , and is treated twice from the position 8 cm above the web to one side of the web. gave. In addition, squeeze the water with a mangle roll, 98
A non-woven fabric was obtained by drying with a dryer at ℃.

Comparative Example 1 The web obtained under the same conditions as in Example 1 was fed onto a 100-mesh wire net, water was applied by a water applicator, and then the water pressure was applied.
A high-pressure columnar flow of 30 kg / cm ² was jetted to obtain a nonwoven fabric.

Comparative Example 2 The web obtained under the same conditions as in Example 1 was fed onto a 100-mesh wire net and water was applied by a water applicator, followed by hydrostatic pressure.
A high-pressure water columnar flow of 60 kg / cm ² was jetted to obtain a nonwoven fabric.

Comparative Example 3 The web obtained under the same conditions as in Example 1 was fed onto a 6-mesh wire net, water was applied by a water applicator, and the water pressure was adjusted to 30.
A non-woven fabric was obtained by jetting a high-pressure columnar flow of kg / cm ² .

Comparative Example 4 Polypropylene having a melting point of 160 ° C. and MFR 400 was spun at a spinning temperature.
Melt spinning at 280 ℃, single hole discharge 0.2 g / min, temperature 320
It was pulled by heated air having a pressure of 1.4 kg / cm ² at ℃. The obtained yarn is collected and accumulated on a net moving at a speed of 6.7 m / min at a position 20 cm away from the spinneret to form a web, and then this web is supplied to an embossing roller with a pressure contact area of 14.2% and a temperature of 110 ° C. Then, thermocompression bonding was performed to obtain a nonwoven fabric. The characteristics of the nonwoven fabrics obtained in Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 1.

[0037]

[Table 1]

As is clear from Table 1, the non-woven fabrics obtained in Examples 1 to 5 had a mixture of interlaced parts and open parts and were excellent in mechanical properties and flexibility. On the other hand, the non-woven fabrics obtained in Comparative Examples 1 and 2 were excellent in mechanical properties, but were non-perforated and poor in flexibility. Further, the nonwoven fabric obtained in Comparative Example 3 was excellent in flexibility, but the area of the opening was too large, resulting in poor mechanical properties and impracticality. The non-woven fabric obtained in Comparative Example 4 was excellent in mechanical properties, but it was a non-perforated non-woven fabric because it was thermocompression bonded by an embossing roller, and was also inferior in flexibility.

[0039]

Industrial Applicability According to the present invention, there is provided an open-entangled ultrafine fiber nonwoven fabric which is excellent in mechanical properties, dimensional stability and flexibility and is suitable for various sanitary materials, industrial materials and clothing. Further, according to the production method of the present invention, it becomes possible to easily and stably produce the open-hole entangled ultrafine fiber nonwoven fabric having the above advantages.

Claims (2)

[Claims] 1. A non-woven fabric composed of ultrafine fibers having an average fiber diameter of 0.1 to 10 μm, wherein the constituent fibers are three-dimensionally entangled with each other and the area has an opening. Mixed, the average porosity is 20 to 50%, and the compression stiffness is
An open-cell entangled ultrafine fiber non-woven fabric, which is 0.3 g / g / m ² or less. 2. A fiber-forming resin is melt-spun, at a temperature 20 to 50 ° C. higher than the spinning temperature, and at a pressure of 1.0 to 2.5 Kg / c.
A high-speed gas of m ² was used to draw and deposit the web on a moving net, and then the web was transferred onto a wire mesh of 10 to 50 mesh, and a high-pressure liquid stream was made to act on the fibers to form tertiary fibers. A method for producing an open-entangled ultrafine fiber nonwoven fabric, which is characterized by causing original openings and opening.