JP2003013353A - Spun-bond nonwoven fabric - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a spun-bond nonwoven fabric having bulkiness and flexibility which the conventional polyethylene terephthalate-based spun-bond nonwoven fabric has been unable to achieve. SOLUTION: This spun-bond nonwoven fabric comprises an eccentric core- sheath type conjugate fiber or bimetal type conjugate fiber having at least one component composed of polypropylene terephthalate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spunbonded nonwoven fabric, and more particularly to a spunbonded nonwoven fabric having excellent breathability, flexibility, bulkiness, stretchability and moldability.

[0002]

2. Description of the Related Art In recent years, non-woven fabrics are used for various purposes because of their excellent air permeability and flexibility, and their uses are expanding. Further, various characteristics are required according to the use, and improvement of the characteristics is required. Among them, spunbonded nonwoven fabrics are currently used for various purposes. The spunbonded nonwoven fabric has an advantage that it is superior in tensile strength or high in productivity as compared with the short fiber nonwoven fabric obtained by the card method. On the other hand, however, it has a drawback that it is inferior in bulkiness and flexibility as compared with the above-mentioned short fiber nonwoven fabric.

It is known that in order to impart bulkiness and flexibility to the spunbonded nonwoven fabric, it is effective to crimp the long fibers which are constituent fibers. This is because the crimping of the long fibers increases the volume of the gaps between the long fibers to increase the bulkiness, and the crimping provides the long fibers with ease of movement to improve flexibility.

As a conventional technique, for example, an eccentric core-sheath type composite fiber or a bimetal type composite fiber composed of two kinds of thermoplastic resins is accumulated to form a nonwoven fabric, and then the composite fiber is contracted to obtain different types. Japanese Patent Application Laid-Open No. 48-1471 discloses a spunbonded non-woven fabric having crimpable fibers that have been crimped by utilizing the difference in shrinkage of thermoplastic resins as constituent fibers.
It is disclosed in Japanese Patent Laid-Open No. 63-283350. In addition, polyethylene terephthalate and a polyethylene terephthalate copolymer having a different intrinsic viscosity from that of polyethylene terephthalate are used as raw materials, and these two polyesters are spun using a side-by-side type composite spinning hole. A method for forming a side-by-side type fiber having crimps and producing a non-woven fabric using the fiber is disclosed in JP-A-2-182963. However, in the above technique, since polyethylene terephthalate causes crimps due to a difference in shrinkage ratio due to a difference in intrinsic viscosity or a difference in copolymerization amount, crimp is insufficient and bulkiness is low. Due to the rigidity, the flexibility was insufficient.

[0005]

DISCLOSURE OF THE INVENTION The present invention provides a spunbonded nonwoven fabric having bulkiness and flexibility which cannot be achieved by conventional polyethylene terephthalate type spunbonded nonwoven fabrics.

[0006]

That is, the present invention has the following constitution in order to achieve the above object.

In a spunbonded non-woven fabric composed of an eccentric core-sheath type composite fiber or a bimetal type composite fiber composed of 1.2 kinds of polyester polymers, at least one of the two kinds of polyester polymers is polypropylene terephthalate. Spunbond nonwoven fabric.

2. The eccentric core-sheath composite fiber core-sheath composite or bimetal composite fiber has a composite range of 40/60 to 60 /
40 is a spunbonded nonwoven fabric according to item 1.

3. A spunbonded nonwoven fabric according to item 1 or 2, characterized in that polypropylene terephthalate is used as each of the two types of polyester polymers.

4. The spunbonded nonwoven fabric according to item 1 or 2, wherein the other of the two types of polyester polymers is polyethylene terephthalate.

5. 5. The spunbonded nonwoven fabric according to claim 4, wherein the eccentric core-sheath type composite fiber has a core component of polyethylene terephthalate and a sheath component of polypropylene terephthalate.

6. The spunbonded nonwoven fabric according to any one of items 1 to 5, wherein the single fiber fineness of the composite fiber is 1 dtex or more and less than 7 dtex.

7. 7. The spunbonded nonwoven fabric according to any one of items 1 to 6, wherein the cross-sectional shape of the composite fiber is a modified cross section.

8. 8. The spunbonded non-woven fabric according to any one of 1 to 7, wherein the non-woven fabric is point-bonded and has a bonded area of 5% or more and less than 30%.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a spunbonded nonwoven fabric composed of eccentric core-sheath type composite fibers or bimetal type composite fibers composed of two kinds of polyester polymers.
It is necessary that at least one of the types of polyester polymer is made of polypropylene terephthalate. By using polypropylene terephthalate as one component of the composite fiber, it is possible to obtain a high crimping characteristic which cannot be obtained by the conventional polyethylene terephthalate-based composite yarn, and the flexibility of the polypropylene terephthalate resin can enhance the flexibility of the nonwoven fabric.

The eccentric core-sheath type conjugate fiber of the present invention means a conjugate fiber in which the sheath component polymer covers the fiber surface as shown in FIG. 1 and the core component polymer is not exposed. Further, the bimetal type composite fiber is a composite fiber in which two kinds of polymer components are exposed to each other as shown in FIG. 2, and the shape of the composite interface may be a straight line or a curved line.

The polypropylene terephthalate used in the present invention may contain a copolymerization component capable of forming another ester bond in a proportion of 10 mol% or less. As the copolymerizable compound, for example, isophthalic acid,
Succinic acid, cyclohexanedicarboxylic acid, adipic acid,
Dicarboxylic acids such as dimer acid and sebacic acid, and glycol components such as ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol and polypropylene glycol can be used, but are not limited thereto. Not a thing.

In addition, titanium dioxide as a matting agent, fine particles of silica or alumina as a lubricant, a hindered phenol derivative as an antioxidant, a coloring pigment and the like can be added if necessary.

The composite range of the core-sheath composite or bimetal composite fiber of the eccentric core-sheath type composite fiber constituting the present invention may be any range as long as it exhibits crimp characteristics, but the composite range is 4
It is more preferably 0/60 to 60/40. If the crimping property is low, a spunbonded nonwoven fabric lacking elasticity tends to be formed.

In the spunbonded non-woven fabric composed of the eccentric core-sheath type composite fiber or bimetal type composite fiber composed of two kinds of polyester-based polymers of the present invention, it is necessary that one of the two kinds of polyester-based polymers is polypropylene terephthalate. And the other may be a polyester polymer, such as polypropylene terephthalate, polyethylene terephthalate, or polybutylene terephthalate.

In order to further increase the flexibility of the nonwoven fabric, it is preferable to use polypropylene terephthalate for both of the two types of polyester polymers constituting the eccentric core-sheath type composite fiber or the bimetal type composite fiber composite fiber. Further, in the eccentric core-sheath type composite fiber, it is more preferable that the core component is composed of high-viscosity polypropylene terephthalate and the sheath component is composed of low-viscosity polypropylene terephthalate.

In order to achieve both resilience and flexibility, the core component of the eccentric core-sheath type composite fiber is preferably polyethylene terephthalate and the sheath component is preferably polypropylene terephthalate. Polyethylene terephthalate may contain a copolymerization component capable of forming another ester bond in a proportion of 10 mol% or less. As the copolymerizable compound, for example, diphthalic acid such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, and the like, and as the glycol component, for example, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, Cyclohexanedimethanol, polyethylene glycol, polypropylene glycol and the like can be used, but the present invention is not limited thereto. In addition, titanium dioxide as a matting agent, fine particles of silica or alumina as a lubricant, a hindered phenol derivative as an antioxidant, a coloring pigment and the like can be added as required.

In order to maintain the flexibility and stretchability of the spunbonded nonwoven fabric, the single yarn fineness of the composite fiber constituting the nonwoven fabric is 1
It is preferably dtex or more and less than 7 dtex, and 2
It is more preferably dtex or more and less than 5 dtex. Fineness is 1
When it is less than dtex, the crimping property of the fiber is lowered and the stretchability is reduced. On the other hand, when the fineness is 7 dtex or more, the nonwoven fabric becomes stiff and the flexibility decreases.

Further, the conjugate fiber constituting the spunbonded nonwoven fabric of the present invention may have any cross-sectional shape such as a round cross section, a triangular cross section, an elliptical cross section, a daruma cross section, etc. In consideration of the anisotropy of crimp, a modified cross section is more preferable.

The spunbonded non-woven fabric of the present invention can be bonded by heat bonding using a binder, hot embossing bonding,
Existing bonding and entanglement methods such as ultrasonic embossing, thermal calendering, needle punch entanglement, and water jet entanglement can be used, but the flexibility of the composite fiber is high and the bulkiness and flexibility due to crimping are more easily exhibited. Ultrasonic or hot embossing adhesion is particularly preferred. Furthermore, in the case of ultrasonic or heat embossing adhesion, the adhesion area is 5% or more 30
It is preferably in the range of less than%.

The spunbond of the present invention can be manufactured by a spunbond nonwoven fabric manufacturing apparatus that can obtain existing composite fibers.

As an example, polypropylene terephthalates having different viscosities are separately melted and compounded into a bimetal type in a composite type spin block and discharged as a composite fiber. This composite fiber is pulled and drawn by an ejector and deposited on a net conveyor. It can be manufactured by heat-treating the deposited non-woven fabric before or after embossing to make the crimps visible and winding.

[0028]

EXAMPLES The present invention will be described below with reference to examples. Each characteristic value in the examples was obtained by the following method.

A. Intrinsic viscosity [η] 0.10 g sample for 10 ml orthochlorophenol
Was melted and measured at a temperature of 25 ° C. using an Ostwald viscometer.

B. The strength and elongation of the nonwoven fabric was measured using Tensilon UCT-100 manufactured by Orientec Co., Ltd. according to JIS L1906.

C. A sample with an elastic recovery rate of 5 × 30 cm was pulled by hand using a constant-speed extension type tensile tester with a self-recording device to prevent it from loosening.
It is attached to the gripping interval of 0 cm, and the pulling speed is set to 10% of the gripping interval to stretch it to a predetermined stress. right away,
From the stress-strain curve recorded by unloading at the same speed, the constant elongation up to a predetermined stress was determined as α, and the recovery elongation decreased until the stress became equal to the initial load was determined as β. Elastic recovery rate (%) = (β / α) × 100 Example 1 Polypropylene terephthalate having an intrinsic viscosity [η] of 1.26 as the first component, and intrinsic viscosity [η] of 0.26 as the second component.
80 polypropylene terephthalates were melted in different extruders and supplied to the composite spin block, and discharged as bimetal composite fibers so that the composite ratio of the first component and the second component was 50/50. At this time,
The spinneret has a round discharge hole of 0.3 mmφ in the longitudinal direction.
20 holes × 5 rows were used.

The discharged composite fiber was introduced into a rectangular ejector, pulled and drawn, opened by a frictional charging device, and deposited on a net conveyor equipped with suction inside. The fineness of the bimetal composite fiber at this time is 2.5 dt.
ex, and the net conveyor speed was adjusted so that the basis weight of the nonwoven fabric was 50 g / m ² .

This spunbonded non-woven fabric was introduced into an ultrasonic embossing device composed of a roll having dot-like dots and a plurality of ultrasonic horns without being wound up once, and was adhered. At this time, a roll provided with dot-like dots having an adhesion area of 20% was used.

Furthermore, the internal temperature of this nonwoven fabric is 100 ° C.
Was introduced into an infrared dryer for 10 minutes so that the crimp was developed to obtain a spunbonded nonwoven fabric.

The physical properties of this spunbonded non-woven fabric are strength 1
0kg / 5cm, elongation 80%, elongation at stress 2kg 40
%, The elastic recovery rate was 98%, indicating good elastic recovery and flexibility.

Example 2 Polypropylene terephthalate having an intrinsic viscosity [η] of 0.89 as the first component and an intrinsic viscosity [η] of 0.29 as the second component.
Example 66 except that 66 polyethylene terephthalate was used, melted in different extruders and supplied to a composite spin block, and was discharged as a bimetallic composite fiber so that the composite ratio of the first component and the second component was 50/50. 1
A spunbonded non-woven fabric was obtained by the same method as described above.

The physical properties of this spunbonded non-woven fabric are strength 1
4kg / 5cm, elongation 70%, elongation at stress 2kg 30
%, The elastic recovery rate was 90%, indicating good elastic recovery and flexibility.

Example 3 Polypropylene terephthalate having an intrinsic viscosity [η] 1.20 as a core component and an intrinsic viscosity [η] 0.89 as a sheath component.
Polypropylene terephthalate was used, melted in different extruders, supplied to a composite spin block, and discharged as eccentric core-sheath composite fiber so that the composite ratio of the first component and the second component was 50/50. A spunbonded nonwoven fabric was obtained in the same manner as in Example 1.

The physical properties of this spunbonded non-woven fabric are a strength of 9
kg / 5 cm, elongation 75%, elongation at stress 2 kg 37
%, The elastic recovery rate was 95%, indicating good elastic recovery and flexibility.

Example 4 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.66 was used as a core component, and polypropylene terephthalate having an intrinsic viscosity of [η] 0.89 was used as a sheath component, and melted in different extruders to form a composite spin block. Supply,
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the eccentric core-sheath composite fiber was discharged so that the composite ratio of the first component and the second component was 50/50.

The physical properties of this spunbonded non-woven fabric are strength 1
2kg / 5cm, elongation 63%, elongation at stress 2kg 28
%, The elastic recovery rate was 92%, indicating good elastic recovery and flexibility.

Example 5 Polypropylene terephthalate having an intrinsic viscosity [η] of 1.26 as the first component, and an intrinsic viscosity [η] of 0.26 as the second component.
80 polypropylene terephthalates were melted in different extruders and supplied to the composite spin block, and discharged as bimetal composite fibers so that the composite ratio of the first component and the second component was 50/50. At this time,
The spinneret was spunbonded in the same manner as in Example 1 except that slit-shaped discharge holes having a long side of 0.5 mm and a short side of 0.3 mm were arranged in a longitudinal direction of 220 holes × 5 rows. A non-woven fabric was obtained.

The physical properties of this spunbonded nonwoven fabric are strength 1
2 kg / 5 cm, elongation 85%, elongation at stress 2 kg 43
%, The elastic recovery rate was 92%, indicating good elastic recovery and flexibility.

Comparative Example 1 Polyethylene terephthalate having an intrinsic viscosity [η] of 0.66 as the first component, and intrinsic viscosity [η] 0.4 as the second component.
A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the polyethylene terephthalate of 7 was used.

This spunbond nonwoven fabric has a strength of 17 kg.
/ 5 cm, elongation 30%, elongation at stress 2 kg of 10%, elastic recovery rate of 60%, which was inferior in elastic recovery and flexibility.

[0046]

EFFECTS OF THE INVENTION By using the composite crimped fiber using polypropylene terephthalate as at least one component as in the present invention, excellent stretchability and flexibility, bulkiness and air permeability which have not been obtained in the past and molding processability can be obtained. An excellent spunbond nonwoven fabric can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a typical eccentric core-sheath type composite fiber of the present invention.

FIG. 2 is a cross-sectional view of a typical bimetal composite fiber of the present invention.

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Claims (8)

[Claims] 1. A spunbonded nonwoven fabric composed of eccentric core-sheath type composite fibers or bimetal type composite fibers composed of two kinds of polyester polymers, wherein at least one of the two kinds of polyester polymers is polypropylene terephthalate. Spunbond nonwoven fabric. 2. The eccentric core-sheath composite fiber core-sheath composite or bimetal composite fiber has a composite range of 40/60 to 60/40.
The spunbonded non-woven fabric according to claim 1, wherein 3. The spunbonded nonwoven fabric according to claim 1, wherein both of the two types of polyester polymers are polypropylene terephthalate. 4. The spunbonded nonwoven fabric according to claim 1, wherein the other of the two types of polyester polymers is polyethylene terephthalate. 5. The spunbonded non-woven fabric according to claim 4, wherein the core component of the eccentric core-sheath type composite fiber is polyethylene terephthalate and the sheath component is polypropylene terephthalate. 6. The single yarn fineness of the composite fiber is 1 dtex or more and 7 d.
It is less than tex, The spun bond nonwoven fabric according to any one of claims 1 to 5 characterized by things. 7. The spunbonded non-woven fabric according to claim 1, wherein the cross-sectional shape of the composite fiber is an irregular cross section. 8. The spunbonded non-woven fabric according to any one of claims 1 to 7, wherein the non-woven fabric is point-bonded and has an adhesion area of 5% or more and less than 30%.