KR20180031313A - SheathCore Hollow Composite Fiber With Dimensional Stability - Google Patents

Abstract

The present invention relates to hollow composite fibers having a sheath part and a core part while having excellent stability. The core part consists of polyester (PET) or polypropylene (PP) resin, while the sheath part consists of either the polyethylene or polyethylene copolymer having a melting point of 80°C to 135°C. The hollow composite fibers can be spun through a complex spinning nozzle having a dual-disk shape by including inner and outer disk-shaped nozzles having a predetermined gap between the nozzles. The inner disk-shaped nozzle spins out a core part resin while the outer disk-shaped nozzle spins out the sheath part resin. The complex spinning nozzle has two to five identical slits at predetermined intervals while inclined surfaces of the slits are parallel or match the extension lines of the core parts of the complex spinning nozzles. The hollow rate of the hollow parts satisfying the following formulas is 7% or greater. Formula 1 is described as 3.5 < IV/ a < 6.0, Formula 2 is described as 1.0 < MI/(a×100) < 2.0, and Formula 3 is described as 2.0 < a/b < 3.5, wherein a is the maximum width of the slits, b is the gap between the inner and outer disk nozzle, IV is the intrinsic viscosity (dL/g) of the polyester resin, and MI is the melt flow index.

Description

[0002] Sheath Core Hollow Composite Fiber With Dimensional Stability [

The present invention relates to a sheath core hollow composite fiber excellent in shape stability that can be used as a nonwoven binder, and more particularly, to a core portion of a fiber capable of maintaining the shape stability of a sheath portion and a hollow portion of a low melting point fiber which can be used as a binder And more particularly to a hollow composite fiber formed.

The heat-bondable composite fiber can be produced by heat fusion using thermal energy such as hot air. The heat-bondable conjugate fiber is generally composed of two components, and by melting only one component by heat, a bulk nonwoven fabric can be easily obtained through bonding of the fibers, and thus it is widely used in industrial materials. BACKGROUND ART [0002] Polyester thermally adhesive type conjugated fibers are widely used as household articles such as automobiles, building materials, sanitary materials, and nonwoven fabrics for filters.

Generally, the polyester-based heat-bonding type conjugate fiber is produced by forming a core by using a general polyester as a first component, forming a core by copolymerization of a copolymer polyol having a condensation product of a dicarboxylic acid component containing terephthalic acid and a diol component containing ethylene glycol And an ester is used as a second component to form a sheath. The two-component heat-bondable composite fibers having different melting points can be applied not only to the core-sheath form, but also to the parallel form, the split form, and the like. The core-sheath form can also be manufactured in the form of core-sheath concentricity and core-sheath eccentricity. On the other hand, the cross-sectional shape of the fibers may be a circular cross-section or a non-circular cross-section.

Korean Patent No. 1224095 discloses a thermosetting conjugate fiber comprising a first component made of a polyester resin and a second component made of a polyolefin resin having a melting point lower than the melting point of the polyester resin by at least 20 DEG C, However, since there is no formation of hollow part in the composite fiber, there is a limitation in improvement of the permeability and there is also a problem in elasticity.

U.S. Patent No. 4,065,439 discloses a method for producing a low melting point polyester by using terephthalic acid / isophthalic acid / adipic acid (or sebacic acid) and ethylene glycol / neopentyl glycol. In this case, however, It is very low at 60 ° C and it is difficult to use it as a wick for a garment.

U.S. Patent No. 788,377, Japanese Patent Application Laid-Open No. 8-143,657, and Korean Patent Publication No. 96-9776 disclose that other carboxylate materials capable of realizing an amorphous molecular structure have a carboxyl group position rather than a meta position of isophthalic acid Attempts have been made to polymerize using more or less bendable ortho-position phthalic acid or phthalic anhydride.

However, in the case of phthalic anhydride, the higher the content in the copolymer, the greater the drop in the glass transition temperature, which may lead to the fusion of the fibers during the drawing process, product transportation or dropping.

In recent years, the performance of nonwoven fabrics such as automobiles, building materials, and sanitary materials has been diversified, and functions such as lightweight, bulky, sound-absorbing and warming have been emphasized. Therefore, , Sound absorption properties, and bulkiness, etc., are required to be developed.

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the problems of the prior art as described above, and it is an object of the present invention to provide a sheath core conjugate fiber which is excellent in heat adhesion and is suitable for a nonwoven binder.

Another object of the present invention is to provide a sheath core conjugate fiber which is excellent in the shape stability of a hollow portion having an effect of being lightweight, bulky, sound-absorbing and heat-retaining as hollow fibers.

It is still another object of the present invention to provide a sheath core conjugated fiber having good processability.

According to an aspect of the present invention, there is provided a hollow composite fiber having a sheath portion and a core portion, wherein the core portion is formed of a polyester (PET) or polypropylene (PP) resin, ° C, and the hollow composite fibers are radiated through a composite spinneret having a double annular shape composed of inner and outer annular apertures having mutually constant intervals, wherein the inner annular recess is formed of a core resin Characterized in that the outer annular detachment is characterized in that the resin of the sheath is radiated and said composite spinneret has two to five identical shaped slits at a constant distance and wherein the slopes of the slits are parallel or coincident with the extension of the central part of the composite spinneret And the void ratio of the hollow part satisfying the following formula is 7% or more. It provides a metaphor.

Equation (1): 3.5 &lt; IV / a &lt; 6.0

(2): 1.0 &lt; MI / (a x 100) &lt; 2.0

Expression (3): 2.0 &lt; a / b &lt; 3.5

here,

a: the longest width of the slit, b: the spacing of the inner and outer annular detents

IV: Intrinsic viscosity (dL / g) of the polyester resin, MI: Melt flow index of the polypropylene resin (g / min, 230 deg.

In the present invention, the longest width a of the slit is 0.1 to 0.15 mm, the interval b between the inner and outer annular recesses is 0.03 to 0.05 mm, and the intrinsic viscosity IV of the polyester resin is 0.50 - 0.60 dL / g, and the polypropylene resin has a melt flow index (MI) of 15 to 35 (g / 10 min, 230 DEG C).

Also, the present invention provides a sheath core hollow fiber having excellent shape stability, wherein the sheath portion and the core portion are formed at a weight ratio of 30:70 to 70:30.

Also, the present invention provides a sheath core hollow fiber having excellent shape stability, wherein the sheath portion and the core portion are formed at a weight ratio of 30:70 to 70:30.

The present invention also provides a nonwoven fabric characterized by containing the heat-bonding conjugated fiber.

As described above, the sheath-core hollow composite fiber having excellent shape stability according to the present invention is suitable for a nonwoven fabric binder having excellent heat bonding performance through the copolymerized polyester resin of the sheath.

In addition, the function of lightweight, bulky, sound-absorbing, and heat-insulating properties can be applied to a nonwoven fabric through a hollow having excellent morphology stability formed in the sheath core hollow composite fiber of the present invention, have.

1A and 1B are conceptual diagrams of a cross-section of a spinneret used for spinning of a sheath core hollow composite fiber having excellent shape stability according to the present invention.
Fig. 2 is a photograph of a cross-sectional view of a sheath hollow hollow fiber having excellent shape stability, which is one embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts are denoted by the same reference numerals whenever possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms &quot; about, &quot; &quot; substantially, &quot; &quot; etc. &quot;, when used to refer to a manufacturing or material tolerance inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

1A and 1B are conceptual diagrams of a cross section of a composite spinneret 1 used for spinning of a sheath core hollow composite fiber having excellent shape stability according to the present invention. FIG. 2 is a cross- 1 is a photograph showing a cross-sectional view of a composite fiber.

In the hollow composite fiber having a sheath portion and a core portion, the core portion is formed of a polyester or a polypropylene resin, and the sheath portion may be formed of any one of a polyethylene or a polyethylene copolymer having a melting point of 80 to 135 DEG C .

The polyester resin of the core part may use any one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polytrimethylene terephthalate (PTT).

If the intrinsic viscosity of the polyester resin is high, the hollow shape in the core portion in the core portion may increase in the direction of the inner circumference during the manufacture of the hollow-type Cisco-type thermally adhesive composite fiber, and the hollow ratio of the hollow portion may also decrease. Therefore, The viscosity is preferably 0.50 to 0.64 dL / g.

A polypropylene resin may be used instead of the polyester resin of the core portion, and the melt flow index (MI) thereof is 15 to 35 (g / 10 min, 230 ° C).

The sheath is a low-melting-point polymer and has a melting point of about 80 ° C to 135 ° C. Suitable low-melting-point polyolefins include polyethylene, such as high density polyethylene, medium density polyethylene, low density polyethylene and linear low density polyethylene, polypropylene, for example isotactic polypropylene and atactic polypropylene; Polybutylenes such as poly (1-butene) and poly (2-butene); Polypentenes such as poly (2-pentene), and poly (4-methyl-1-pentene); Polyvinyl acetate; Polyvinyl chloride; polystyrene; And copolymers thereof, such as ethylene-propylene copolymers, and blends thereof.

Among these, more preferred polyolefins are polypropylene, polyethylene, polybutylene, polypentene, polyvinyl acetate, and copolymers and blends thereof.

The most preferred polyolefins for the present invention are polypropylene, polyethylene, copolymers of polypropylene and polyethylene, and combinations thereof

The sheath core hollow composite fiber is a hollow fiber composite fiber. The hollow fiber ratio is a factor that directly affects the multifunctional performance such as lightweight, bulky, sound-absorbing and thermal insulation. If the hollow fiber ratio is too low, the lightweight, , Heat retention and the like may be deteriorated, so that the hollow ratio is preferably 7% or more.

Therefore, in order to exhibit the above-mentioned multifunctional performance, not only the void ratio of the hollow portion 10 of the sheath core hollow composite fiber but also the shape stability of the hollow portion after the radiation is important.

In the present invention, the structural numerical limitations of the composite spinneret (1) are limited at the time of composite spinning for the shape stability of the hollow part. To this end, the composite fiber yarn is radiated through a composite spinneret (1) of a double annular configuration consisting of inner and outer annular sleeves of uniform spacing, the inner annular sleeve (20) comprising a core resin, an outer annular retainer ) Of the composite spinning tool (1) emits sheath resin, and the composite spinneret (1) has 2 to 5 slits of the same shape at a certain distance, and the slopes of the slits are parallel or coincide with extension lines of the center of the composite spinneret .

In addition, in order to maintain the characteristic that the hollow ratio is 7% or more and the shape stability is excellent, the numerical value by the following expression is necessary.

Equation (1): 3.5 &lt; IV / a &lt; 6.0

(2): 1.0 &lt; MI / (a x 100) &lt; 2.0

Expression (3): 2.0 &lt; a / b &lt; 3.5

here,

a: the longest width value of the slit, b: the interval value of the inner and outer annular detents

IV: Intrinsic viscosity of polyester resin, MI: Melt flow index of polypropylene resin

Generally, unstretched hollow composite fibers discharged through spinneret swell due to pressure difference. If the swelling direction is toward the hollow portion, a desired hollow ratio can not be obtained or a desired cross-sectional shape can not be obtained depending on the swelling direction.

Therefore, in order to improve the morphological stability of the conjugate fiber of the hollow portion, slits are formed at regular intervals in the annular-shaped spinneret in consideration of the physical properties of the discharged resin (IV) and the flow index (MI) It is possible to prevent the shape deformation caused by the contact.

The number of slits may be two or more, but preferably two to five, more preferably three to four. It is also appropriate that the intervals of the plurality of slits are the same and the shapes are also the same. If the number of slits is small, there is a problem in buffering discharge expansion. If the number of slits is too large, there may be difficulties in manufacturing and cost of spinning.

Also, in the case of sheath core composite spinning, the spacing (b) between the outer sheath and the inner annular sheath to which the sheath part and the core part are discharged is also important for shape stability. This is because the composition of the sheath portion and the core portion is different from that of the resin, so that the swelling degree is different.

The shape of the slope of the slit may be parallel or coincide with an imaginary line that coincides with an extension of the center of the composite spinneret.

Fig. 1B shows that the width of the slit becomes larger as the outer diameter of the spinneret increases, and the longest width a of the slit appears at the outermost angle. Due to the nature of the annular shape, the circumference becomes larger toward the outer side, and the ratio of the discharge expansion is also large. Therefore, it is possible to compensate the buffering action of the slit considering the difference of the swelling according to the distance from the spinneret center of the discharged composite yarn.

The sheath portion and the core portion may be formed to have a weight ratio of 30:70 to 70:30 to form the sheath core hollow composite fiber of the present invention.

The nonwoven fabric comprising the sheath core hollow conjugate fiber according to the present invention formed as described above will be capable of manifesting the functions of light weight, bulky property, sound absorption property, and warmth property of the sheath core hollow conjugate fiber through the nonwoven fabric.

Hereinafter, examples of the method for producing the multifunctional thermally adhesive composite fiber according to the present invention will be described, but the present invention is not limited to the examples.

Example  One

Polyethylene terephthalate (PET) having an intrinsic viscosity (IV) of 0.55 dL / g was used as a core part, and polyethylene (PE) having a melt flow index MI (g / 10 min, 190 degrees)

The polyethylene terephthalate (PET) and polyethylene (PE) were spun through a sheath core hollow composite spinneret (FIG. 1 (a)) at a spinning speed of 1000 m / min. To prepare a sheath core composite fiber having a fineness of 3 to 5 denier by cutting to 38 mm.

Example  2

The longest width (a) of the slits of the composite spinneret 1 was set to 0.1 mm, in the same manner as in Example 1 above.

Example  3,4

The longest width (a) of the slit of the composite spinneret and the interval (b) between the inner and outer ring-shaped spinneret were measured in the same manner as in Example 1, Used

Example  5 ~ 7

The core part was used as polypropylene (PP), and the values of a and b of the melt flow index and composite spinneret were as shown in Table 1.

Comparative Example  1 to 7

Table 1 shows the materials of the core and sheath, melt flow index, intrinsic viscosity, and a and b values of the composite spinneret.

The physical property data of the above Examples and Comparative Examples are shown in Tables 1 and 2.

The physical properties were measured by the following method.

(1) Hollowness (%): The ratio of the area occupied by the hollow fiber through the cross-sectional image of the fiber measured by the optical microscope was calculated by the following formula.

  - Hollow area / fiber area (including hollow) * 100 (%)

(2) Core / Sheath Cross-sectional shape: Judged by naked eye through the cross-sectional image of the fiber measured by optical microscope.

(3) Strength and elongation: The strength and elongation of the fiber were measured using a tensile strength tester manufactured by Instron, under conditions of a sample length of 20 cm and a tensile speed of 25 cm / min.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7


Core portion Material PET PET PET PET PP PP PP IV (dL / g) 0.55 0.55 0.55 0.55 - - - MI (g / 10 min, 230 degrees) - - - - 16 20 25 IV / a 3.6 5.5 4.58 5.5


Shebu

Material material PE PE PE PE PE PE PE IV - - - - - - - MI (g / 10 min, 190 degrees) 20 20 20 20 20 20 20 MI / (a x 100) 1.33 2 1.66 2 1.06 1.33 1.92 complex
radiation
Detention a Spacing (mm) 0.15 0.1 0.12 0.1 0.15 0.15 0.13 b Spacing (mm) 0.05 0.05 0.05 0.03 0.05 0.05 0.05 a / b 3 2 2.4 3.3 3 3 2.4

Properties
Hollowness (%) 10 11 10 10 11 12 12 Core / Sheath Sectional Form Good Good Good Good Good Good Good Strength (g / d) 3.8 3.6 3.9 3.5 3.6 3.7 3.5 Shinto (%) 60 57 60 54 82 79 81 Fairness Good Good Good Good Good Good Good

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7


Core portion
Material PET PET PET PET PET PP PP IV (dL / g) 0.55 0.55 0.55 0.64 0.49 - - MI (g / min, 230 degrees) - - - - - 10 25     IV / a 2.75 3.66 11 4.26 3.26 0.66 1.66



Shebu Material PE PE PE PE PE PE PE IV - - - - - - - MI (g / min, 190 degrees) 20 20 20 20 20 20 20 MI / (a x 100) One 1.33 4 1.33 1.33 1.33 1.33 complex
radiation
Detention a Spacing (mm) 0.2 0.15 0.05 0.15 0.15 0.15 0.15 b Spacing (mm) 0.05 0.1 0.05 0.05 0.05 0.05 0.05 a / b 4 1.5 One 3 3 3 3

Properties
Hollowness (%) 5 4 3 5 3 5 4 Core / Sheath Sectional Form Bad Bad Bad Bad Bad Bad Bad Strength (g / d) 3 3.1 3.2 3.5 1.2 3.1 1.4 Shinto (%) 40 45 45 43 43 50 60 Fairness Bad Bad Bad Bad Very bad Bad Very bad

(1), (2) and (3) using the composite spinneret of the present invention (Fig. 1 (a) As shown in Fig. 3, the sheath part, the core part, and the hollow part are clearly distinguished, and the hollow part is also close to the circular shape, so that the hollow part (%) is at least 10 or more and the shape stability can be influenced on the warmth and lightness And the elongation is also superior to the comparative example.

On the other hand, the comparative example shows that the void ratio is less than 7% and the cross-sectional shape of the sheath core is poor when the numerical limitations of the equations (1), (2) and (3) are exceeded. Fairness is also poor.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. It will be clear to those who have knowledge of.

1: composite spinneret 10: hollow
20: internal annular detention 30: external annular detention
a: the longest width of the slit b: the spacing of the inner and outer annular indentations

Claims (4)

A hollow composite fiber having a sheath portion and a core portion,
The core portion is formed of a polyester (PET) or polypropylene (PP) resin,
The sheath is formed of any one of a polyethylene or a polyethylene copolymer having a melting point of 80 to 135 DEG C,
Wherein the hollow composite fibers are spun through a composite spinneret having a double annular shape composed of inner and outer annular spacers having a constant spacing,
Wherein the inner annular nipple has a core portion resin and the outer annular nipple has a sheath portion resin, the composite spinneret has two to five identical-shaped slits at a certain distance,
The inclined surface of the slit is parallel or coincides with an extension of the central portion of the composite spinneret,
Wherein the hollow portion satisfying the following formula has a hollow ratio of 7% or more.

Equation (1): 3.5 &lt; IV / a &lt; 6.0
(2): 1.0 &lt; MI / (a x 100) &lt; 2.0
Expression (3): 2.0 &lt; a / b &lt; 3.5

here,
a: the longest width of the slit, b: the spacing of the inner and outer annular detents
IV: Intrinsic viscosity (dL / g) of the polyester resin, MI: Melt flow index of the polypropylene resin (g / min, 230 deg.
The method according to claim 1,
The longest width a of the slit is 0.1 to 0.15 mm, the interval b between the inner and outer annular detents is 0.03 to 0.05 mm,
Wherein the polyester resin has an intrinsic viscosity (IV) of 0.50 to 0.60 dL / g and a melt flow index (MI) of 15 to 35 (g / 10 min, 230 DEG C) Excellent sheath core hollow fiber.
The method according to claim 1,
Wherein the sheath portion and the core portion have a weight ratio of 30:70 to 70:30.
A nonwoven fabric comprising the thermally adhesive composite fiber according to any one of claims 1 to 3.

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