JP2003013354A - 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 polybutylene 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 eccentric core-sheath type composite fibers or bimetallic type composite fibers composed of 1.2 kinds of polyester polymers, at least one of the two kinds of polyester polymers is polybutylene terephthalate. Characteristic 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. The spunbonded non-woven fabric according to item 1 or 2, wherein each of the two types of polyester polymers is polybutylene terephthalate.

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. 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 polybutylene 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.
At least one of the polyester polymers of the type needs to be polybutylene terephthalate. By using polybutylene terephthalate as one component of the composite fiber, it is possible to obtain a high crimping property which cannot be obtained with the conventional polyethylene terephthalate-based composite yarn, and the flexibility of the polybutylene terephthalate resin enhances the flexibility of the nonwoven fabric. Exploiting high dyeability, it can be expected to be applied to clothing applications.

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 polybutylene 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, 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 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 nonwoven fabric composed of the eccentric core-sheath type composite fiber or bimetal type composite fiber composed of two kinds of polyester polymers of the present invention, at least one of the two kinds of polyester polymers is polybutylene terephthalate. The other is a polyester polymer, and any of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate and the like may be used.

In order to further increase the flexibility of the nonwoven fabric, it is preferable to use polybutylene terephthalate as both of the two types of polyester polymers that constitute 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 polybutylene terephthalate and the sheath component is composed of low viscosity polybutylene 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 polybutylene 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. Also, titanium dioxide as a matting agent,
If necessary, 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.

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, polybutylene terephthalate 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 Polybutylene terephthalate having an intrinsic viscosity [η] of 1.51 as the first component, and intrinsic viscosity [η] 0.8 as the second component.
Polybutylene terephthalate of No. 2 was melted in different extruders and supplied to the composite spin block, and discharged as a bimetallic composite fiber so that the composite ratio of the first component and the second component was 40/60. At this time, the spinneret has a round discharge hole of 0.3 mmφ in the longitudinal direction.
An arrangement with 0 holes × 5 rows was 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
2kg / 5cm, elongation 82%, elongation at stress 2kg 38
%, The elastic recovery rate was 96%, indicating good elastic recovery and flexibility.

Example 2 Polybutylene terephthalate having an intrinsic viscosity [η] 0.82 as the first component and an intrinsic viscosity [η] 0.6 as the second component.
Example 6 except that polyethylene terephthalate of No. 6 was melted in different extruders and supplied to the 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 60/40 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
3 kg / 5 cm, elongation 72%, elongation at stress 2 kg 33
%, The elastic recovery rate was 91%, indicating good elastic recovery and flexibility.

Example 3 Polybutylene terephthalate having an intrinsic viscosity [η] of 1.51 was used as a core component, and polybutylene terephthalate having an intrinsic viscosity of [η] 0.82 was used as a sheath component. A spunbonded nonwoven fabric was obtained in the same manner as in Example 1 except that the mixture was supplied to a block and discharged as eccentric core-sheath composite fibers 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
0 kg / 5 cm, Elongation 78%, Elongation 39 at 2 kg stress
%, The elastic recovery rate was 94%, 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 polybutylene terephthalate having an intrinsic viscosity of [η] 0.82 was used as a sheath component, and each was melted in a different extruder to obtain a composite spin block. 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
4kg / 5cm, elongation 65%, elongation at stress 2kg 30
%, The elastic recovery rate was 91%, indicating good elastic recovery and flexibility.

Example 5 Polybutylene terephthalate having an intrinsic viscosity [η] of 1.51 as the first component, and intrinsic viscosity [η] 0.8 as the second component.
Polybutylene terephthalate of No. 2 was melted in different extruders and supplied to the composite spin block, and discharged as a bimetallic composite fiber so that the composite ratio of the first component and the second component was 40/60. At this time, the same method as in Example 1 was used except that the spinneret had slit-shaped discharge holes having a long side of 0.5 mm and a short side of 0.3 mm arranged in 220 holes × 5 rows in the longitudinal direction. A spunbonded nonwoven fabric was obtained.

The physical properties of this spunbonded nonwoven fabric are strength 1
5kg / 5cm, elongation 86%, elongation at stress 2kg 45
%, The elastic recovery rate was 95%, 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 54%, which was inferior in elastic recovery and flexibility.

[0046]

EFFECTS OF THE INVENTION By using the composite crimped fiber using polybutylene terephthalate as at least one component as in the present invention, excellent stretchability and flexibility, bulkiness, and air permeability which have not been hitherto obtained, and molding processing can be performed. A spunbonded nonwoven fabric having excellent properties 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. In a spunbonded nonwoven fabric composed of eccentric core-sheath type composite fibers or bimetal type composite fibers composed of two kinds of polyester polymers, at least one of the two kinds of polyester polymers is polybutylene terephthalate. Characteristic 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 polybutylene 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 composite fiber is polyethylene terephthalate and the sheath component is polybutylene 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%.