JPH0841765A - Continuous filament non-woven fabric and its production - Google Patents

Abstract

PURPOSE:To produce a continuous filament nonwoven fabric which can be readily bonded by thermal compression without paying prudent care and keeps its surface not flattened like film even when it is strongly heat-compressed, thus shows very excellent mechanical properties, flexibility and draping properties. CONSTITUTION:This non-woven fabric is formed of continuous conjugated filament constituted with the first fiber-forming polymer 1 and the second fiber- forming polymer which melts at a temperature 20 deg.C or more lower than that of the first polymer. On the cross section of this conjugated filament, the first polymer 1 and the second one 2 occupy each a certain range along the circumference and the proportion of the second polymer 2 amounts to 5-15% in the total cross section, when it is calculated along the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a long-fiber non-woven fabric used for a wide variety of purposes such as sanitary materials, daily life materials and industrial materials, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method for producing a long-fiber nonwoven fabric, a fiber-forming polymer is melt-spun, and a spun yarn is pulled and thinned by an air sucker and then deposited on a conveyor net. There is a method in which a web is formed and the web is subjected to heat pressure contact with a heat pressure contact device. Examples of the heat-pressure welding device include a device including an embossing roll and a flat roll, and a device including a pair of embossing rolls.

Various cross-sections of this spun yarn are selected depending on the required characteristics of the nonwoven fabric. That is,
When using the fiber-forming polymer alone, a single-layer circular cross section,
Single-layer hollow sections, single-layer irregular sections, etc. are applied. When two or more kinds of fiber-forming polymers are used, composite core-sheath cross section, composite hollow cross section, composite irregular cross section, composite side-by-side cross section, composite split fiber section, mixed fiber composite, etc. are widely applied. For example, a composite core-sheath cross section is required if high mechanical properties are required for a nonwoven fabric, a hollow cross section is given if lightweight properties are given to the nonwoven fabric, a modified cross section or a composite side-by-side cross section is given if flexibility is given to the nonwoven fabric, and a filter effect is applied to the nonwoven fabric. In addition, various transverse cross-section structures are selected depending on the required properties of the non-woven fabric, such as a composite split cross-section made of fine-fineness yarns, if drapeability is given.

[0004]

However, such a conventional nonwoven fabric has the following disadvantages. That is, in the single-layer cross section, since it is a fully melted type, the heat contact temperature must be delicately controlled. In other words, when the heat-welding temperature is too high for the fiber web, partial melting of the heat-welding portion occurs and the boundary portion between the non-pressure-welding portion and the pressure-welding portion is significantly weakened. However, serious problems such as adherence of the melted material to deteriorate the operability, melting of the pressure contact portion more than necessary to form a hole, or cutting of the product from the pressure contact portion will occur. On the other hand, if the hot press contact temperature is too low, no fusion occurs at all, or the fusion force becomes extremely weak.
Therefore, the obtained product is inferior in mechanical performance, and fluff is liable to be generated in appearance, so that it cannot be used at all. This obstacle cannot be improved by changing the yarn cross section.

In order to obtain a long-fiber non-woven fabric which is a fully melted type and has excellent mechanical performance, it is generally heat-pressed at a temperature 30 to 50 ° C. lower than the melting point and then impregnated with a resin as a binder. It's dried. However, this method has a drawback that the resin cost, the apparatus cost, and the running cost such as energy are high.

On the other hand, even a composite cross section using two or more kinds of fiber-forming polymers, the conventional one has the following disadvantages. For example, in JP-A-63-165564, a fiber having a cross-section of a composite core-sheath in which a fiber-forming polymer having a low melting point is arranged in a sheath part and a fiber-forming polymer having a high melting point is arranged in a core part is disclosed. A non-woven fabric is disclosed. In this case, it is true that the sheath portion has an indefinite shape due to the heat pressure contact at a temperature in the vicinity of the melting point of the low melting point component, but the core portion remains without significant deterioration due to heat. Also, in the hot-pressing step, if the melting point difference between the two components is set to 15 ° C. or more, the core part remains without melting even if the hot-pressing temperature is slightly high, so that the product has significantly poor mechanical properties. Concerns are small. However,
Since the low-melting point component is present all around the fiber surface, if the hot-pressing temperature is too high, the melt of the fiber may adhere to the emboss used in the hot-pressing step, resulting in a significant loss of operability. This may result in deterioration of flexibility and drape of the obtained product. Even if the composite ratio of the core-sheath portion or the yarn cross-sectional shape is changed, this obstacle cannot be improved as long as the low melting point component is present on the entire circumference of the fiber surface.

In the case of a composite side-by-side cross section, for example, by bonding a fiber-forming polymer having a different viscosity,
A crimp is developed in high-order processing, and a differentiated nonwoven fabric excellent in bulkiness and flexibility can be obtained. However, this composite side-by-side cross section has a composite ratio of both materials of about 50.
It is generally set to / 50 (weight ratio). If the compounding ratio is changed extremely, the yarn bending angle becomes large when the two melts bonded together are spun from the spinneret in the yarn making process. For this reason, the spinneret is soiled over time, spinning operability is impaired, and the desired bulkiness and flexibility cannot be imparted to the nonwoven fabric. In order to prevent this, the composite ratio is set to about 50/50 (weight ratio) as described above, but the fiber web obtained under these conditions has the composite core-sheath cross section described above. Similarly, increasing the hot press temperature can result in melt sticking to the embossments and in the resulting softness and drape of the resulting product.

Further, in the case of imparting a filter effect and drapability to a non-woven fabric, that is, in the case of applying a composite split cross section to form a fine-fineness yarn in a high-order processing, and imparting a filter effect and a drapability to the non-woven fabric (Japanese Patent Laid-Open No. Hei 10-1999) 3-2
According to 94557 and Japanese Patent Laid-Open No. 4-82952, the non-woven fabric composed of fine fiber certainly has many excellent properties as compared with the conventional non-woven fabric composed of yarn of 2 to 15 denier. . However, since the yarn cross section before splitting is intended to obtain more and smaller fineness, the number of laminated layers of both components in the circumferential direction of the fiber cross section increases. As a result, similar to the cross section of the composite core-sheath described above, if the hot press contact temperature is increased, the same trouble will occur.

In the case of the mixed fiber composite, different components are pulled and thinned at the same suction speed, so that the spinning operability is poor. Moreover, similar to the cross section of the composite core-sheath described above, if the hot press contact temperature is increased, the same trouble will occur. Also, the products obtained with this type generally tend to have poor mechanical performance uniformity.

The present invention solves such a problem and
It can be easily heat-pressed without particular care, the surface of the non-woven fabric does not become a film even when strongly heat-pressed, and it has excellent mechanical properties, flexibility and drapeability. The present invention provides a fibrous nonwoven fabric and a method for inexpensively producing this long-fiber nonwoven fabric.

[0011]

The present inventors have arrived at the present invention as a result of earnest studies to achieve the above object. That is, the gist of the present invention is the following configuration. (1) A non-woven fabric in which a nonwoven web made of composite long fibers is partially heat-pressed to maintain a predetermined shape, and comprises a first fiber-forming polymer and the first fiber-forming polymer. It is formed by a composite long fiber composed of a second fiber-forming polymer having a melting point of 20 ° C. or more lower than that of the coalescence, and in the cross section of the composite long fiber, the first fiber-forming polymer and the second fiber-forming polymer are formed. Of the second fiber-forming polymer occupying a constant range in the circumferential direction and occupying the entire cross-sectional area of the cross section of the composite continuous fiber in the circumferential direction. A long-fiber non-woven fabric characterized by a ratio of 5 to 15%. (2) A method for producing a non-woven fabric in which a nonwoven web made of composite long fibers is partially heat-pressed to maintain a predetermined shape, the first fiber-forming polymer and the first fiber. A second fiber-forming polymer having a melting point of 20 ° C. or more lower than that of the polymer forming polymer, and the first fiber-forming polymer and the second fiber-forming polymer are arranged in a circumferential direction in a cross section. Of the composite fiber in such a manner that the ratio of the cross-sectional area of the second fiber-forming polymer to the total cross-sectional area along the circumferential direction of the cross section is 5 to 15%. Spinning
A non-woven web is formed by the composite long fibers, and when the non-woven web is represented by the melting point of the second fiber-forming polymer as t, the thermal pressing temperature T is set in the range of the following equation, and t <T < t + 15 ° C. A method for producing a long-fiber non-woven fabric, which comprises performing partial heat pressure contact with an embossing roll having a pressure contact area ratio of 4 to 40%.
Next, the present invention will be described in detail.

First, the composite long fibers for forming the nonwoven fabric will be described. This composite continuous fiber comprises a first fiber-forming polymer (hereinafter referred to as “high melting point component”) and 20 ° C. higher than the first fiber-forming polymer, that is, a low melting point component.
The second fiber-forming polymer having a low melting point (hereinafter referred to as "low melting point component").

The fiber-forming polymers that form the high melting point component and the low melting point component are typically polyesters such as polyethylene terephthalate, polybutylene terephthalate, and isophthalic acid copolymerized polyethylene terephthalate, nylon 6, nylon 66, and the like. It is made of a polymer such as polyamide or polyolefin such as polyethylene or polypropylene. It also includes blends of these polymers and copolymers of these polymers.

The high melting point component and the low melting point component include
Any additive such as a matting agent, a pigment, a flameproofing agent, an antiseptic agent, an antistatic agent, an antioxidant, and an ultraviolet absorber may be added to the extent that the object of the present invention is not impaired.

In the combination of the high melting point component and the low melting point component, it is preferable that the two components are compatible with each other. The reason for this is that if both components are incompatible, phase separation of both components occurs in the composite cross-sectional form, and various obstacles are induced in the deposition and pressure welding steps when obtaining a nonwoven fabric, which is not preferable. For this reason, it is preferable that the high melting point component is a homopolymer and the low melting point component is a copolymerization polymer of the high melting point component.

It is preferable that the low melting point component has a higher melt viscosity than the high melting point component. This is because embedding the low melting point component of the high viscosity material in the high melting point component of the low viscosity material is effective in terms of stability of the composite cross section.

It is necessary that the melting point of the low melting point component is lower than the melting point of the high melting point component by 20 ° C. or more. 20 ° C difference in melting point
If it is less than, not only the high melting point component is softened or melted during thermocompression bonding using a thermocompression bonding apparatus, but also the softening of the fiber and the melt adhere to the embossing roll which is a thermocompression bonding apparatus, impairing the operability. However, the surface of the non-woven fabric becomes a film to impair the quality, and a long fiber non-woven fabric excellent in mechanical properties and flexibility cannot be obtained. For this reason, the melting point difference is 25 ° C.
It is more preferable that the above is satisfied.

The single yarn fineness of the composite long fibers is preferably 1.5 to 15 denier. If it is less than 1.5 denier, the fibers are too thin, so that a stable composite cross section cannot be obtained in the spinning process and also yarn breakage is induced.
Not preferred. On the other hand, if it exceeds 15 denier, the pressure contact between the fibers is easily displaced due to the thick fibers, and the mechanical performance and flexibility of the obtained nonwoven fabric are impaired. For this reason, 2-12 denier is more preferred.

In the composite continuous fiber according to the present invention, the cross section of the composite fiber is such that the low melting point component is partly exposed with respect to the high melting point component, so that the conventional low melting point component covers 100% of the fiber surface. With a composite core-sheath cross section,
The low melting point component and the high melting point component are alternately laminated in the circumferential direction, and the hot pressing temperature which cannot be applied at all in the case of the composite split fiber cross section in which the low melting point component occupies about 50% of the fiber surface can be applied. That is, according to the present invention, since the low melting point component occupies only a part of the fiber surface in the cross section of the composite long fiber, the low melting point component has a very short cycle with respect to the heated thermocompression bonding device and Contact and leave in a short time. Therefore, even if the hot press contact temperature is equal to or higher than the melting point of the low melting point component, the melt of the low melting point component does not adhere to the hot press contacting device and impair the operability. Moreover, since the surface of the obtained long-fiber nonwoven fabric does not become a film, the product is of good quality.

Here, the low melting point component acts as a binder function, but a sufficient amount of heat is imparted to the low melting point component even though the low melting point component occupies a part of the fiber surface. As a result, it exhibits excellent adhesion performance and anti-fluffing property. In addition, the high-melting point component does not become a film because it becomes the matrix of the long fibers that make up the non-woven fabric and does not deteriorate or become atypical with respect to the applied heat, and it has excellent mechanical performance and flexibility. Shows sexuality and drape.

Therefore, the ratio of the cross-sectional area of the low melting point component to the total cross-sectional area along the circumferential direction of the cross section is 5 to 5.
It must be in the range of 15%. When the cross-sectional ratio of the low-melting point component exceeds 15%, the pressure-bonding area between the fibers becomes too large, so the long-fiber nonwoven fabric obtained has excellent mechanical performance, but the hot-pressing temperature is equivalent to the melting point of the low-melting-point component. Alternatively, if the melting point is higher than the melting point, the melt of the fibers adheres to the emboss used in the heat-pressing process, resulting in a marked loss of operability, or the flexibility and drape of the obtained product are impaired. Or On the other hand, when the content is less than 5%, although the material is hot pressed in the vicinity of the melting point of the low melting point component, the fusion of the fibers is insufficient because the low melting point component is too small, and the flexibility of the obtained long fiber nonwoven fabric is Although it is excellent, it is inferior in mechanical properties, and further, fluff is generated on the surface of the non-woven fabric, so that it cannot be used at all.
For this reason, it is more preferable that the cross-sectional ratio of the low melting point component is 7 to 12%.

A schematic view of a composite cross section applicable to the present invention is shown in FIGS. Here, the fiber has a circular cross section, 1 is a high melting point component, and 2 is a low melting point component. In FIG. 1, the fan-shaped low-melting point component 2 is arranged at one position in the circumferential direction with respect to the high-melting point component 1. In FIG. 2, the fan-shaped low-melting point component 2 having a small angle is arranged at three locations in the circumferential direction with respect to the high-melting point component 1. However, this is only a schematic diagram, and the number of the low melting point components 2 to be arranged may be appropriately determined, and the arrangement of 1 to 10 places is preferable. Furthermore, even if the fiber cross section is irregular or hollow, there is no problem.

Next, a method for manufacturing the long fiber nonwoven fabric of the present invention will be described. When producing the long-fiber nonwoven fabric of the present invention, two types of fiber-forming polymers having different melting points are separately melted, and the low melting point component occupying in the total cross-sectional area along the circumferential direction of the cross section is cut. After being individually weighed so that the area ratio is 5 to 15%, both molten materials are supplied to, for example, a composite spinneret capable of forming the cross-sectional structure shown in FIGS.
The yarn spun from the spinneret is cooled using a conventionally known cooling device such as horizontal spraying or annular spraying, and then drawn and drawn to a target fineness using an air sucker. The pulling speed is preferably 3500 m / min or more, and particularly preferably 4000 m / min or more because the dimensional stability of the nonwoven fabric is improved. The composite fiber discharged from the air sucker is opened by a general method, and then opened and accumulated on a moving and accumulating device such as a conveyor including a screen to form a web. Then, the web is partially heat-pressed with an embossing roll, which is a heat-pressing device, to obtain a long-fiber nonwoven fabric.

For the heat pressure welding of the web, a heat pressure welding device having an embossing roll and a flat roll, or a heat pressure welding device having a pair of two embossing rolls is used. You may use several thermocompression bonding apparatuses.

At this time, the heat-welding temperature and the pressure-welding area ratio given to the web during the heat-welding are important.
That is, when the web composed of the composite fiber of the high melting point component and the low melting point component is hot pressed by the hot pressing device, the hot pressing temperature T must be within the range of the following formula.

Melting point of low-melting point component <T <melting point of low-melting point component + 15 ° C. When a temperature lower than the melting point of the low-melting point component is applied as the hot pressing temperature T, the mechanical performance and fluff prevention of the obtained long-fiber nonwoven fabric are improved. The result is inferior, which is not preferable. On the contrary, when a temperature higher than the melting point of the low melting point component + 15 ° C. is applied as T, the web is fused to the embossing roll or the flat roll and the operability is remarkably impaired, and the surface of the obtained non-woven fabric becomes a film and the quality is improved. It is inferior to the product and is not preferable. For this reason, T is more preferably in the range of the following formula.

Melting point of low melting point component <T <melting point of low melting point component + 10 ° C. The pressure contact area ratio must be in the range of 4 to 40%.
Here, the pressed area ratio is defined as the ratio of the area of the pressed portion to the entire area of the nonwoven fabric sheet. This is 4
When it is less than%, the long-fiber nonwoven fabric is excellent in flexibility but poor in mechanical performance and fluff prevention property because the pressure contact area is too small, which is not preferable. Conversely, 40
If it exceeds%, the pressure contact area between the fibers is too large, so that the flexibility of the nonwoven fabric is impaired, which is not preferable. For this reason, it is more preferably 10 to 30%.

[0028]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to these examples.

In the following examples, each characteristic value was obtained as follows. -Melting point of polymer: The temperature that gives the maximum value of the melting endothermic peak measured at a temperature rising rate of 20 ° C / min using a DSC-2 type differential scanning calorimeter manufactured by Perkin Elmer was taken as the melting point.

Relative viscosity of polyester: 0.5 g of a sample was dissolved in 100 ml of a mixed solvent of phenol and ethane tetrachloride in an equal weight ratio, and the viscosity was measured by a conventional method at a temperature of 20 ° C.

Melt flow rate of polypropylene (hereinafter referred to as "MFR"): ASTM D1238
It was measured by the method described in (L). -Cross-section ratio of low-melting point component: With respect to the composite fiber pulled and thinned by an air gun, the cross-sectional area of the entire fiber and the cross-sectional area of only the low-melting point component were read using an electron microscope and calculated by the following formula.

Cross-sectional ratio = (cross-sectional area of low melting point component / total cross-sectional area) x 100 (%) Fineness of yarn: Obtained by density correction using an electron microscope for composite fibers pulled and thinned by an air gun. It was

Tensile strength of non-woven fabric: Tensilon UTM-4- manufactured by Toyo Baldwin Co., Ltd., which is a constant-speed extension type test machine
Using a 100 type, a test piece having a width of 5 cm and a length of 30 cm was grabbed, measured under the conditions of an interval of 20 cm and a pulling speed of 20 cm / min, and the average value of 10 measurements was obtained.

Compression stiffness of the nonwoven fabric: Tensilon UTM-4-100 type manufactured by Toyo Baldwin Co., Ltd. was used to bend a test piece having a width (longitudinal direction) of 5 cm and a length (horizontal direction) of 10 cm in the lateral direction to form a cylinder. Shape, and join the ends to make a sample,
This cylindrical material was compressed in the longitudinal direction at a compression speed of 5 cm / min, and the stress at the maximum load was measured to obtain the value. The smaller the value of this compression stiffness is, the more excellent the flexibility is.

Example 1 As a high melting point component, the melting point was 160 ° C. and the MFR was 50 g.
While preparing a polypropylene polymer for / 10 minutes,
Low melting point component, melting point 138 ° C, MFR 30g
/ 10 minutes, and a propylene-based copolymer in which 4% by weight of ethylene was randomly copolymerized was prepared. Using this copolymer, a known melt composite spinning machine and a spinneret capable of forming the composite cross section shown in FIG. 1 were used, and the spinning temperature was 230 ° C.
Spinning was carried out under the conditions that the discharge rate was 1.4 g / hole / min and the composite ratio (high melting point component / low melting point component) was 92/8 wt%. After cooling the spun yarn, 4 by air soccer
The web was collected at a speed of 200 m / min, opened by a known method, and collected and deposited on a moving collecting surface to form a web. The web was heat-pressed using a hot-pressing device including an embossing roll under the conditions of a point pattern, a processing temperature of 145 ° C., and a pressing area ratio of 15% to obtain a long-fiber nonwoven fabric having a basis weight of 30 g / m ² . The fineness of the composite fiber collected from the fiber assembly was 3 denier, and the cross-sectional ratio of the low melting point component was 8%. Table 1 shows the physical properties of this long-fiber nonwoven fabric.

Example 2 Using the same raw material as in Example 1 and using a die capable of forming the composite cross section shown in FIG. 2, the temperature was 230 ° C., the discharge rate was 1.5 g / 1 hole · min, and the composite ratio ( The high-melting point component / low-melting point component) was spun under the condition of 88/12% by weight.
After cooling the spun yarn, 4500 by air sucker
The web was collected at a speed of m / min, opened by a known method, and collected and deposited on a moving collecting surface to form a web. This web was point-patterned, the processing temperature was 145 ° C., and the pressure-contact area ratio was 15 using a heat-pressure welding device consisting of an embossing roll.
% Under the condition of%, and a long fiber nonwoven fabric having a basis weight of 30 g / m ² was obtained. The fineness of the composite fiber collected from the fiber assembly was 3 denier and the cross-sectional ratio of the low melting point component was 12%. Table 1 shows the physical properties of this long-fiber nonwoven fabric.

Example 3 A high melting point component having a melting point of 260 ° C. and a relative viscosity of 1.
A polyethylene terephthalate polymer of No. 38 was prepared, and a copolymer polyester having a melting point of 215 ° C., a relative viscosity of 1.35 and 15 mol% of isophthalic acid as a low melting point component was prepared. Using such a raw material, a known melt composite spinning machine and a spinneret capable of forming the composite cross section shown in FIG. 2 are used, and the spinning temperature is 290.
Spinning was carried out under conditions that the temperature was ℃, the discharge rate was 1.6 g / 1 hole · min, and the composite ratio (high melting point component / low melting point component) was 88/12 wt%. After the spun yarn was cooled, it was taken up by air sucker at a speed of 4800 m / min, opened by a known method, and collected and accumulated on a moving collecting surface to obtain a web. This web was hot pressed with a hot pressing device consisting of an embossing roll under the conditions of a point pattern, a processing temperature of 215 ° C., and a press contact area ratio of 15%, and a basis weight of 30 g / m 2.
A long fiber non-woven fabric of ² was obtained. The fineness of the composite fiber collected from the fiber assembly is 3 denier, and the cross-sectional ratio of the low melting point component is 12
%Met. Table 1 shows the physical properties of this long-fiber nonwoven fabric.

Example 4 Using the same raw material as in Example 3, using a known melt composite spinning machine and a spinneret capable of forming the composite cross section shown in FIG. 2, the spinning temperature was 290 ° C. and the discharge rate was 5.2 g. / 1 hole / minute,
Composite ratio (high melting point component / low melting point component) 88/12% by weight
It was spun under the condition. After cooling the spun yarn, it is taken up by air sucker at a speed of 5000 m / min,
The web was opened by a known method and collected and deposited on the moving collecting surface to form a web. This web was point-patterned at a processing temperature of 2 using a thermocompression bonding device consisting of an embossing roll.
Thermal pressing was performed under the conditions of 35 ° C. and a pressing area ratio of 5% to obtain a long fiber nonwoven fabric having a basis weight of 50 g / m ² . The fineness of the composite fiber collected from the fiber assembly was 8 denier, and the cross-sectional ratio of the low melting point component was 12%. Table 1 shows the physical properties of this long-fiber nonwoven fabric.

Example 5 A nonwoven fabric was obtained in the same manner as in Example 1 except that the pressure contact area ratio was 35%. The results are shown in Table 1.

Comparative Example 1 An attempt was made to obtain a long fiber nonwoven fabric under the same conditions as in Example 1 except that the conditions were changed so that the cross-sectional ratio of the low melting point component was 3%. However, the fusion of the fibers was insufficient because the low-melting point component was too small, and the obtained long-fiber non-woven fabric was excellent in flexibility, but inferior in mechanical properties, and further fluffing of the non-woven fabric surface occurred. However, it was not durable enough to use. In addition, many thread dropouts occurred.

Comparative Example 2 An attempt was made to obtain a long-fiber nonwoven fabric under the same conditions as in Example 1 except that the conditions were changed so that the cross-sectional ratio of the low melting point component was 18%. However, since the cross-section ratio was too high, a melt of polypropylene copolymer, which is a low melting point component, adhered to the embossing roll, and the desired long-fiber nonwoven fabric was not obtained.

Comparative Example 3 An attempt was made to obtain a long-fiber nonwoven fabric under the same conditions as in Example 3 except that the processing temperature of the embossing roll was 210 ° C. However, the temperature of the embossing roll was too low, the fusion force was insufficient, and the surface of the long fiber non-woven fabric had a lot of fluff, so that it was hardly usable.

Comparative Example 4 An attempt was made to obtain a long fiber nonwoven fabric under the same conditions as in Example 3 except that the processing temperature of the embossing roll was 245 ° C. However, since the temperature of the embossing roll was too high, the melt of the polyester copolymer, which is a low melting point component, adhered, and the desired long-fiber nonwoven fabric was not obtained.

Comparative Example 5 An attempt was made to obtain a long fiber non-woven fabric under the same conditions as in Comparative Example 3 except that hot pressing was carried out with the pressing area ratio of the embossing roll being 2%. However, due to insufficient pressure contact, the surface of the long fiber non-woven fabric had many fluffs, and the intended long fiber non-woven fabric could not be obtained.

Comparative Example 6 An attempt was made to obtain a long fiber non-woven fabric under the same conditions as in Comparative Example 3 except that hot pressing was performed with the pressing area ratio of the embossing roll being 50%. However, because the pressure contact was too much,
The surface of the non-woven fabric was formed into a film, and the intended long-fiber non-woven fabric was not obtained.

Comparative Example 7 Using the same material as in Example 3, and using a known melt-composite spinning machine, polyethylene terephthalate having a high melting point component forms a core, and 15 mol% of isophthalic acid having a low melting point component is copolymerized. A die having a core-sheath composite cross section in which the copolymerized polyester thus formed forms a sheath was used. Then, spinning was carried out under the conditions that the spinning temperature was 290 ° C., the discharge rate was 1.5 g / 1 hole · minute, and the composite ratio (high melting point component / low melting point component) was 50/50 wt%. After the spun yarn was cooled, it was taken up by air sucker at a speed of 4500 m / min, opened by a known method, and collected and accumulated on the moving collecting surface to form a web. This web was point-patterned at a processing temperature of 245 using a thermocompression bonding device consisting of an embossing roll.
Heat-pressing was performed under the conditions of a temperature of 15 ° C. and a pressing area ratio of 15% to obtain a long-fiber nonwoven fabric having a basis weight of 30 g / m ² . The fineness of the composite fiber collected from the fiber assembly was 3 denier. In the long fiber nonwoven fabric obtained in this case, the pressure contact portion was melted and a hole was formed, and a part was formed into a film.

[0047]

[Table 1]

As is clear from Table 1, according to Examples 1 to 5 of the present invention, the low melting point component is disposed in a part of the cross section of the conjugate fiber in the circumferential direction, and the embossing roll temperature is set to the low melting point component. Since the temperature was close to the melting point of No. 3, no problems such as the non-woven fabric sticking to the embossing roll occurred, and the obtained long-fiber non-woven fabric was excellent in mechanical performance and flexibility.

On the other hand, in each of Comparative Examples 2, 4, 6, and 7, the melt of the low-melting point component adhered to the hot-pressing device (embossing roll), which markedly impaired the operability. Further, even when a long-fiber nonwoven fabric was obtained, the surface thereof was formed into a film and the flexibility and drape property were impaired. On the contrary, in the case of Comparative Examples 1, 3, and 5, only the result of insufficient thermal pressure welding was obtained.

[0050]

According to the long-fiber nonwoven fabric and the method for producing the same of the present invention, the first fiber-forming polymer (high melting point component) and the second fiber-forming polymer ( Low melting point component) occupies a certain range in the circumferential direction,
The fiber-forming polymer of is exposed on a part of the fiber surface, and the web made of the composite long fibers has a temperature higher than the melting point of the low-melting point component by the embossing roll. Since it is thermocompression-bonded to the web, unlike the conventional method in which the web is pressure-welded at a temperature lower than the melting point of the constituent fiber, excellent adhesive properties can be obtained because the web can be sufficiently thermocompressed. Since it is the matrix of the above, a long-fiber nonwoven fabric excellent in mechanical properties and flexibility can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a composite cross-sectional structure of long fibers constituting a long fiber nonwoven fabric of the present invention.

FIG. 2 is a schematic view showing another example of a composite cross-sectional structure of long fibers.

[Explanation of symbols]

 1 High melting point component 2 Low melting point component

Claims (3)

[Claims] 1. A non-woven fabric in which a nonwoven web made of composite long fibers is partially heat-pressed to maintain a predetermined shape, which comprises a first fiber-forming polymer and the first fiber-forming polymer. Formed by a composite long fiber composed of a second fiber-forming polymer having a melting point of 20 ° C. or more lower than that of the organic polymer, and in the cross section of the composite long fiber, the first fiber-forming polymer The second fiber-forming polymer occupies a certain range in the circumferential direction, and the cross section of the second fiber-forming polymer occupies the entire cross-sectional area of the cross section of the composite continuous fiber in the circumferential direction. A long-fiber nonwoven fabric having an area ratio of 5 to 15%. 2. The continuous fiber non-woven fabric according to claim 1, wherein the single filament fineness of the composite continuous fiber is 1.5 to 15 denier. 3. A method for producing a non-woven fabric in which a nonwoven web made of composite long fibers is partially heat-pressed to maintain a predetermined shape, the first fiber-forming polymer and the first fiber-forming polymer. Of the second fiber-forming polymer having a melting point lower than that of the fiber-forming polymer of 20 ° C. or more, and the first fiber-forming polymer and the second fiber-forming polymer are The composite length occupies a certain range in the circumferential direction and the ratio of the cross-sectional area of the second fiber-forming polymer to the total cross-sectional area along the circumferential direction of the cross section is 5 to 15%. A fiber is spun to form a non-woven web by the composite long fiber, and when the non-woven web is represented by the melting point of the second fiber-forming polymer by t, the hot pressing temperature T is set within the range of the following formula. , T <T <t + 15 ° C For embossing rolls with a pressure contact area ratio of 4 to 40% A method for producing a long-fiber non-woven fabric, which is characterized in that partial heat-bonding is performed.