JPH0782646A - Nonwoven fabric composed of combined filament - Google Patents

Abstract

PURPOSE:To obtain nonwoven fabric excellent in mechanical properties, flexibility, bulkiness and drapeability and suitable for a material for clothing and medical-sanitary use. CONSTITUTION:As the characteristics of this nonwoven fabric composed of combined filaments, three or more kinds of polyethylene terephthalate-based filaments having mutually different cross-sectional shapes combined and the filaments are three-dimensionally entangled with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention comprises a mixture of at least three types of polyethylene terephthalate long fibers having different cross-sectional shapes, and has excellent mechanical performance, flexibility, bulkiness and drapeability. The present invention relates to a long-fiber nonwoven fabric suitable as a material for clothing and medical / sanitary materials.

[0002]

2. Description of the Related Art Conventionally, short-fiber nonwoven fabrics or long-fiber nonwoven fabrics have been used as materials for clothing, medical / sanitary materials, civil engineering materials, agricultural materials or general industrial materials. In the case of short-fiber non-woven fabrics, a method of mixing different shrinkage twin yarns obtained by different heat history in the spinning process or drawing process, or the so-called high-speed spinning method, is used to vary the focusing position of the yarn spun from the spinneret. It is known that a non-woven fabric excellent in flexibility and drapability is obtained by, for example, a method of mixing different shrinkage fiber yarns having different birefringence and shrinkage performance. On the other hand, in the case of the long-fiber nonwoven fabric obtained by the spunbond method, when manufacturing the nonwoven fabric, the melt-spun fiber yarn is cold-stretched / thinned by air resistance using a take-up means such as an air sucker, and the fiber-spreading device is opened. Since the method of forming a web by continuously collecting and depositing on the movable collecting surface after opening the fiber by using the method, the mechanical performance and lint-free property are superior to the short fiber non-woven fabric. Although the number of manufacturing steps is low and the cost is low, it is difficult to make the shrinkage performance between constituent fibers different, and the resulting non-woven fabric has a smooth surface and is rigid. In addition, the flexibility, drapeability, and bulkiness were all inferior. In addition, when producing a long-fiber nonwoven fabric by the spunbond method, the melt-spun fiber yarn is cooled from one side of the fiber, or a combination of different polymers is used to develop crimp in the fiber, thereby making it flexible. It is also known to obtain a non-woven fabric having excellent properties, drapability, and bulkiness, but it has a problem that the manufacturing technique is complicated and the manufacturing cost is increased.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and comprises a mixture of at least three types of polyethylene terephthalate type continuous fibers having mutually different cross-sectional shapes,
An object of the present invention is to provide a long-fiber non-woven fabric which is excellent in mechanical performance, flexibility, bulkiness and drapeability and is suitable as a material for clothing and medical / sanitary materials.

[0004]

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 is characterized in that at least three types of polyethylene terephthalate long fibers having mutually different cross-sectional shapes are mixed and the long fibers are three-dimensionally entangled with each other. The main point is fiber non-woven fabric.

Next, the nonwoven fabric of the present invention will be described in detail. The first feature of the nonwoven fabric of the present invention is that it is composed of polyethylene terephthalate-based long fibers. The term "polyethylene terephthalate" as used herein is substantially composed of polyethylene terephthalate. In addition to ordinary polyethylene terephthalate, phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, adipic acid,
Acid components such as sebacic acid, paraoxybenzoic acid, 5-sodium sulfoisophthalic acid, diethylene glycol, 1,
As long as it is a copolyester obtained by copolymerizing 10 mol% or less of a diol component such as 4-butanediol, neopentyl glycol, polyalkylene glycol, etc. and that each has a fiber-forming property, it is not particularly limited. Absent. In addition, if it is within the range that does not impair the spinnability,
For example, matting agent, pigment, flame retardant, deodorant, antistatic agent,
Antioxidants, ultraviolet absorbers, etc. may be added.
In the non-woven fabric of the present invention, the single fiber fineness of the polyethylene terephthalate-based long fibers constituting the non-woven fabric is not particularly limited, but preferably 1.
It is preferable that it is not less than 2 denier and not more than 8 denier. If the single fiber fineness is less than 1.2 denier, the spinnability during melt spinning during the production of the nonwoven fabric of the present invention and the subsequent stretchability are reduced, while if the single fiber fineness exceeds 8 denier, Since the monofilament is too thick, the resulting non-woven fabric has a feeling of coarseness and hardness, and the openability in the web-making process is deteriorated, which are both unfavorable. Therefore, in the nonwoven fabric of the present invention, it is preferable that the monofilament fineness is 1.2 denier or more and 8 denier or less, and 1.5 denier or more and 6 denier or more.
It is particularly preferable that the denier is not more than that.

The second feature of the nonwoven fabric of the present invention is that at least three kinds of polyethylene terephthalate long fibers having different cross-sectional shapes are mixed. The cross-sectional shape is, for example, a normal circular type as shown in FIG. 1a, a triangular type shown as b, a hexagonal type shown as c, a flat type shown as d, a hollow type shown as e, and a spoon type shown as f. Examples include hollow molds. Of course, in addition to these molds, a T-shaped mold, a square mold, a pentagon mold, a flat hollow mold, and the like may be used. In the nonwoven fabric of the present invention, it is necessary that the polyethylene terephthalate-based long fibers constituting the nonwoven fabric have at least three mutually different cross-sectional shapes selected from the above-mentioned cross-sectional shapes. When the cross-sectional shape of the long fibers is two kinds, although the flexibility and the drapeability are slightly superior to those of a normal nonwoven fabric having one kind of cross-sectional shape, the flexibility excellent as far as the object of the present invention,
A non-woven fabric having bulkiness and drape cannot be obtained. In the nonwoven fabric of the present invention, the mixed fiber ratio (weight ratio) of the at least three types of polyethylene terephthalate-based filaments having mutually different cross-sectional shapes is equal to all the constituent filaments. It is more preferable in that a non-woven fabric having excellent flexibility, bulkiness and drapeability can be obtained. In the nonwoven fabric of the present invention, at least three types of long fibers having different cross-sectional shapes are mixed even though they are formed of the same material. As a result of simultaneously exhibiting different performances, the nonwoven fabric has excellent flexibility, bulkiness and drapeability. In addition, by appropriately selecting the cross-sectional shape, the non-woven fabric can have so-called shearing performance.

The third characteristic of the nonwoven fabric of the present invention is that the long fibers are three-dimensionally entangled with each other. In the non-woven fabric of the present invention, a three-dimensional entanglement is formed between the long fibers by a known so-called high-pressure liquid flow treatment, whereby the shape of the non-woven fabric is maintained and the strength which is generally required as the non-woven fabric is high. It is equipped, and the flexibility can be improved.

The nonwoven fabric of the present invention can be efficiently manufactured by the following method. That is, a polyethylene terephthalate polymer is melt-spun from a spinneret in which at least three types of modified spinning holes having different cross-sectional shapes are perforated, and a plurality of spun long fiber yarns are arranged under the spinneret. At the same time, at least three types of spun filament yarns having different cross-sectional shapes are introduced at the same time for each air sucker, and they are pulled / stretched / taken off, and a corona discharge opener in a high piezoelectric field is introduced. Alternatively, after the fiber is opened by the opening means such as a friction charger, it is continuously collected on the movable collection surface.
It is a method in which the long fibers are three-dimensionally entangled with each other by depositing them to form a web and then subjecting them to a high pressure liquid flow treatment. In addition, after the polyethylene terephthalate polymer is melt-spun from a spinneret having at least three types of modified spinning holes having different cross-sectional shapes, the spun long fiber yarn is taken up by a take-up roller. , A drawing roller arranged between the take-up roller and a drawing roller arranged on the downstream side of the take-up roller and heated to a temperature not lower than the glass transition temperature and not higher than the melting point of the polyethylene terephthalate polymer, thereby carrying out hot drawing, It is also a method in which the long fibers are three-dimensionally entangled with each other by introducing them into and taking them out, thereafter forming a web in the same manner as described above, and then performing a high pressure liquid flow treatment.

When melt-spinning a polyethylene terephthalate polymer from a spinneret having at least three types of modified spinning holes having different cross-sectional shapes, the configuration of the modified spinning holes drilled in the spinneret is It is important to appropriately optimize various dimensions such as the diameter of the spinning holes and the length and width of the slit holes in order to prevent the mutual fusion of the melt spun filaments or the occurrence of filament cutting due to the fusion. is there. The cross-sectional shape of the modified spinning hole is, for example, a normal circular shape as shown in FIG. 2a, a Y-shaped shape as shown in b, a hexagonal shape as shown in c, a flat shape as shown in d, and a double shape as shown in e. Examples include a heavy C-shape, a hollow hollow mold shown in f, and the like. Of course, besides these types,
It may be a T-shaped type, a square type, a pentagonal type, a flat hollow type or the like. In melt spinning, the single fiber fineness of the polyethylene terephthalate long fibers is preferably 1.2 denier or more and 8 denier or less in terms of circular cross section. As described above, when the single fiber fineness is less than 1.2 denier, the spinnability during melt spinning and the subsequent stretchability are deteriorated, while when the single fiber fineness exceeds 8 denier,
Both are not preferable because the openability in the web-making process is deteriorated and the obtained nonwoven fabric has a coarse and hard feeling because the single fibers are too thick. Therefore, in the present invention, the single fiber fineness is preferably 1.2 denier or more and 8 denier or less, and particularly preferably 1.5 denier or more and 6 denier or less. Further, as the stretching means, a heating plate, a heating cylinder or a heat roller having a temperature not lower than the glass transition temperature of the polyethylene terephthalate polymer and not higher than the melting point can be adopted. At this time, the temperature of the stretching means is polyethylene terephthalate polymer. If the temperature is below the glass transition temperature of, it becomes difficult to perform stretching efficiently and stably. On the other hand, if the temperature of the stretching means exceeds the melting point of the polyethylene terephthalate polymer, so-called super draw stretching is performed, neither of which is preferable. .

When performing the high-pressure liquid flow treatment, for example, the pore diameter is 0.05 to 1.0 mm, especially 0.1 to 0.4 m.
The injection pressure is 5 to 15 using a device in which a large number of m injection holes are arranged in one row or a plurality of rows with a hole interval of 0.3 to 10 mm.
It is preferable to adopt a method of ejecting a high-pressure liquid of 0 kg / cm ² G from the ejection hole. The injection holes are arranged in rows in a direction orthogonal to the direction of travel of the web. Water or warm water is generally used as the high-pressure liquid, and water mixed with an additive can also be used. The distance between the injection hole and the web is preferably 1 to 15 cm. If this distance is less than 1 cm, the texture of the nonwoven fabric obtained by this treatment is disturbed, while this distance is 15 cm.
If it exceeds, the impact force when the liquid stream collides with the web is reduced and three-dimensional entanglement is not sufficiently performed, either of which is not preferable. This high-pressure liquid flow treatment can be performed from one side of the web as well as from both sides at the same time. However, when the treatment from one side is performed by the following method, a nonwoven fabric excellent in uniformity and compactness can be obtained. It is possible to obtain and is preferable. That is, first, the pressure is 5 to 50 k as the first stage process.
A high-pressure liquid flow of g / cm ² G is jetted to collide with the web to pre-entangle the constituent long fibers of the web, and then the pressure is 50 to 150 kg / c as the second stage treatment.
This is a method in which a high-pressure liquid stream of m ² G is jetted and collided with a web, and the long fibers constituting the web are highly three-dimensionally entangled to be integrated as a whole. In this method, when the pressure of the liquid flow is less than 5 kg / cm ² G in the treatment of the first step, the constituent long fibers of the web cannot be pre-entangled, while the liquid flow is When the pressure exceeds 50 kg / cm ² G, when the high-pressure liquid flow is jetted into the web and collided, the long fibers constituting the surface layer of the web are disturbed by the action of the liquid flow, and the web itself is disturbed in texture and is unevenly spotted. Therefore, neither is preferable.
In addition, in the processing of the second stage, the pressure of the liquid flow is 50
If it is less than kg / cm ² G, the above-mentioned long fibers cannot be highly three-dimensionally entangled with each other, while
When the pressure of the liquid flow exceeds 150 kg / cm ² G, the flexibility of the obtained nonwoven fabric is not improved, which is not preferable.
Further, when performing this high-pressure liquid flow treatment, as a supporting material for supporting the web, for example, a mesh screen such as a wire mesh of 20 to 200 mesh, a perforated plate, or the like, through which the high-pressure liquid flow can penetrate the web. It is not particularly limited as long as it is.

After the high pressure liquid flow treatment, excess moisture is removed from the treated web. A known method can be adopted for removing the excess water. For example, a squeezing device such as a mangle roll may be used to mechanically remove excess water to some extent, and then a remaining amount of water may be removed using a drying device such as a continuous hot air dryer to obtain a final nonwoven product. In addition to the normal dry heat treatment, the dry treatment may be a wet heat treatment, if necessary. Further, when selecting the processing conditions such as the drying processing temperature and time for performing the drying processing, the conditions may be selected not only to simply remove water but also to allow appropriate shrinkage.

[0012]

EXAMPLES Next, the present invention will be specifically described based on Examples. The measurement and evaluation of various characteristics in the examples were carried out by the following methods. Melting point (° C.) of polymer: The temperature which gives the extreme value of the melting absorption heat curve measured at a temperature rising rate of 20 ° C./min using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elma Co., Ltd. is referred to as the melting point (° C.). did. Glass transition temperature (° C.) of polymer: using differential scanning calorimeter DSC-2 type manufactured by Perkin Elmer Co., Ltd., temperature rising rate 20 ° C. /
Measured in minutes. Intrinsic viscosity of polymer: Intrinsic viscosity of the polymer was measured by the following method. That is, an equal weight mixture of phenol and tetrachloroethane was used as a solvent, and the measurement was carried out by a conventional method at a temperature of 20 ° C. Tensile strength (kg / 5 cm width) of non-woven fabric: Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.
It was measured according to the strip method described in IS L-1096. That is, the sample width is 5 cm and the sample length is 10 cm.
10 pieces of the sample are prepared, and the pulling speed is 10 cm for each sample.
The maximum tensile strength (kg) was obtained by measuring in 1 / min, and the average value of the obtained tensile strength values was divided by the sample width of 5 cm to obtain the tensile strength (kg / 5 cm width) of the nonwoven fabric. Tensile elongation (%) of nonwoven fabric: Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.
Each piece was measured at a tensile speed of 10 cm / min, and the average value of the obtained tensile elongations (%) was defined as the tensile elongation (%) of the nonwoven fabric. Bulk density (g / cm ³ ) of the nonwoven fabric: A total of 5 sample pieces having a sample length of 10 cm and a sample width of 10 cm were prepared, and a basis weight w (g / m ² ) was measured for each sample piece. Then, using a thickness measuring instrument (manufactured by Daiei Kagaku Seiki Seisakusho) for each sample, 4.5 g
Thickness t after applying a load of / cm ² for 10 seconds
(Mm) was measured, and the average value of the bulk density (g / cm ³ ) values calculated by the following formula (1) was used to calculate the bulk density (g / c) of the nonwoven fabric.
m ³ ). Bulk density (g / cm ³ ) = w / t × 1000 (1) Non-woven fabric compression stiffness (g): sample length 10 cm, sample width 5 cm A total of 5 points were prepared, each sample piece was bent in the lateral direction to form a cylindrical object, and the end portions thereof were joined to each other to obtain a sample for measuring compression stiffness. Then, the axial direction of each measurement sample was compressed at a compression speed of 5 cm / min using a constant-speed extension type tensile tester (Tensilon UTM-4-1-100 manufactured by Toyo Baldwin Co., Ltd.) to obtain the maximum obtained. The average value of the load values (g) was defined as the compression stiffness of the nonwoven fabric (g).

EXAMPLE 1 A chip of a polyethylene terephthalate polymer having a melting point of 259 ° C., a glass transition temperature of 68 ° C. and an intrinsic viscosity of 0.70 was melted at a temperature of 290 ° C. by using a conventional melt spinning apparatus, and then, as shown in FIG. The spinneret in which three types of atypical spinning holes of circular type, Y-type and flat type described in 1) are alternately bored on the circumference (each spinning hole number is 40, total spinning hole number is 120) Through single-hole discharge was 2.0 g / min, melt spinning was performed, and the spun filament group was cooled using a cooling device. Subsequently, a total of 4 groups of the spun long fiber groups (the number of long fibers per group is 30)
The screen conveyor is divided into four parts, and each group is introduced into a total of four air saws arranged under the spinneret, towed, stretched, and picked up, and then opened by a corona discharge opener in a high-voltage field and then moved. A web was formed by depositing the web on top, and then the obtained web was subjected to a high-pressure liquid flow treatment to three-dimensionally entangle the long fibers. When performing the high-pressure liquid flow treatment, a web was placed on a mesh screen made of 100 mesh and a jet machine having a hole diameter of 0.12 mm was arranged in 5 groups with a hole interval of 0.6 mm. A jet of water with a jet pressure of 30 kg / cm ² G is jetted from a position 5 cm above the web to collide with the web, and then the web is turned over, and then a jet of water with a jet pressure of 80 kg / cm ² G is 5 cm above the web. It was ejected from the position of and was made to collide with the web. Then, excess water is mechanically removed from the web after the high-pressure liquid stream treatment by using a mangle roll, and then the remaining water is removed by a saxion dryer heated to a temperature of 95 ° C to obtain a final product. A mixed fiber long fiber non-woven fabric was obtained. The obtained mixed-fiber long-fiber nonwoven fabric has a basis weight of 60 g / m.
² , tensile strength is 16.8kg / 5cm width in longitudinal direction, 1.7kg / 5cm width in transverse direction, tensile elongation is 45% in longitudinal direction, 210% in transverse direction, compressive bending resistance is 8.4g, and bulk density is 0. .05
It had a characteristic of 8 g / cm ³ .

Comparative Example 1 A spinneret in which two types of circular and Y-shaped modified spinning holes shown in FIG. 1 were alternately punched on the circumference (60 spinning holes, total spinning holes) A mixed filament long fiber nonwoven fabric was obtained in the same manner as in Example 1 except that the number of holes was 120). The obtained mixed fiber long-fiber non-woven fabric has a basis weight of 62 g / m ² , a tensile strength of 17.4 kg / 5 cm in the longitudinal direction, and a transverse direction of 1.8 kg / 5.
cm width, tensile elongation 42% in lengthwise direction, 201% in widthwise direction, compression bending resistance 12.9 g, bulk density 0.088 g / cm ^3.
It had the characteristics of.

Comparative Example 1 Example 1 was repeated except that a spinneret having circular spinning holes having a hole diameter of 0.5 mm perforated on the circumference (total number of spinning holes was 120) was used.
In the same manner as described above, a mixed fiber long fiber non-woven fabric was obtained. The obtained mixed-fiber long-fiber non-woven fabric has a basis weight of 62 g / m ² , a tensile strength of 18.5 kg / 5 cm in the longitudinal direction, and a transverse direction of 1.7 kg / 5 c.
The m width and tensile elongation were 46% in the longitudinal direction, 213% in the transverse direction, the compression stiffness was 14.7 g, and the bulk density was 0.106 g / cm ³ .

In Example 1 using a spinneret having three types of modified spinning holes, the obtained mixed-fiber long-fiber nonwoven fabric has practically sufficient tensile strength, and is excellent in flexibility and bulkiness. It was a thing. On the other hand, in Comparative Example 1 using the spinneret in which two types of irregularly shaped spinning holes are punched, the obtained mixed-fiber long-fiber non-woven fabric has practically sufficient tensile strength, but has flexibility and bulkiness. It was inferior to that of Example 1.
Further, in Comparative Example 1 using the spinneret in which only the circular spinning holes were perforated, the flexibility and bulkiness were further inferior.

[0017]

EFFECTS OF THE INVENTION The mixed filament long-fiber nonwoven fabric of the present invention is formed by mixing at least three kinds of polyethylene terephthalate long filaments having mutually different cross-sectional shapes, and the long filaments are three-dimensionally entangled. It has excellent mechanical performance, flexibility, bulkiness and drape, and is suitable as a material for clothing and medical / sanitary materials.

[Brief description of drawings]

FIG. 1 is a schematic view showing a cross-sectional shape of long fibers constituting a nonwoven fabric of the present invention.

FIG. 2 is a schematic view showing a cross-sectional shape of atypical spinning holes that can be used when manufacturing the nonwoven fabric of the present invention.

Claims (1)

[Claims] 1. At least 3 having mutually different sectional shapes.
Polyethylene terephthalate type long fibers are mixed and
In addition, a mixed fiber long-fiber nonwoven fabric, wherein the long fibers are three-dimensionally entangled with each other.