KR101350508B1 - Thermally bondable core-sheath type composite fiber, manufacturing method thereof and use thereof - Google Patents

Abstract

The present invention provides a thermally bondable core-sheath type composite fiber consisting of a core containing a polyester-based resin and inorganic minute particles and a sheath containing a polyolefin-based resin having a lower melting point than the polyester-based resin constituting the core by at least 10°C and inorganic minute particles. Here, the weight ratio of the core to the sheath is 55:45 to 65:35 in the composite fiber; the content of the inorganic minute particles in the core is 0.5-5 parts by weight based on 100 parts by weight of the polyester-based resin; the content of the inorganic minute particles in the sheath is 0.1-1.5 parts by weight based on 100 parts by weight of the polyolefin-based resin; and the elongation at break of the composite fiber is 30-80%. The thermally bondable core-sheath type composite fiber according to the present invention has good spinning property at the time of melt-spinning and has no occurrence of core-sheath interface delamination. In addition, when a woven fabric is made by using the thermally bondable core-sheath type composite fiber according to the present invention, the web formation is good and dust particles are hardly generated. Further, the woven fabric made of the thermally bondable core-sheath type composite fiber according to the present invention has excellent bulkiness and tensile strength.

Description

Thermo-bondable core sheath type composite fiber, manufacturing method thereof and use thereof {Thermally bondable core-sheath type composite fiber, manufacturing method etc.

The present invention relates to a heat-sealable edible composite fiber and a method for manufacturing the same, and more particularly, to a heat-fused composite fiber and a method for producing the same, which have excellent bulk properties and minimize interfacial peeling between the core and the core.

The present invention also relates to the use of the heat-sealing cardiac composite fiber as a nonwoven material.

Conventionally, thermally fused composite fibers, which can be formed by thermal fusion using thermal energy such as hot air or a heating roll, can easily obtain bulkiness. Thus, hygienic materials such as diapers, napkins, and pads can be obtained. Or widely used in industrial materials such as household goods and filters. In particular, hygiene materials are required to have a liquid-absorbing property because they are in direct contact with the skin, and need to quickly absorb liquids such as touch, touch, urine, and menstrual blood, and have bulk properties A method of obtaining a fiber and a nonwoven fabric having a fiber-reinforced polypropylene fiber has been proposed.

For example, a bulky nonwoven fabric is produced by using a sheath-core composite fiber having a polypropylene of high isotacticity as a core component and a sheath component mainly composed of a resin composed of polyethylene. A method is disclosed (see Japanese Patent Laid-Open No. 63-135549). This method imparts bulkiness to the resulting nonwoven fabric by using a high rigid resin on the core side of the composite fiber, but it is not sufficient in flexibility, and particularly when the thermal fusion temperature becomes high, the bulkiness of the resulting nonwoven fabric also decreases. Compatibility of eggplant properties was difficult. Moreover, the method of providing bulkiness using polyester or a sheath component for polyester and a sheath component for a core component is also proposed (Japanese Unexamined-Japanese-Patent No. 2000-336526, Unexamined-Japanese-Patent No. 3-21648). In Japanese Unexamined Patent Application Publication No. 2000-336526, a sheath-core composite fiber using a polyester having a melting point of 20 ° C. or more higher than the melting point of the polyolefin in the sheath component and the core component is stretched and crimped. ) After imparting, the hot air superheat treatment is performed at a temperature of 10 ° C. or higher than the glass transition temperature of the polyester and at a temperature of 20 ° C. or higher for the melting point of the polyolefin, thereby imparting flexibility and bulkiness to the nonwoven fabric. When thermal fusion was carried out at a temperature equal to or higher than the melting point of the polyolefin, the morphological stability of the crimp against heat was insufficient, resulting in a decrease in thickness due to the growth or shrinkage of the crimp, which made it difficult to obtain a bulky nonwoven fabric. On the other hand, Japanese Unexamined Patent Application Publication No. 3-21648 discloses a bulky nonwoven fabric by using polyethylene or polypropylene as the adhesive component and polyester as another component, and performing heat treatment for adjustment in a predetermined temperature range after stretching or crimping. Although it provided, in this case, although the bulk property was excellent, the flexibility of the nonwoven fabric obtained was inadequate. Moreover, in this method, elongation of crimp may generate | occur | produce in the adjustment process, and the form stability of crimp still remains.

In order to overcome the above problems, Korean Patent Publication No. 10-1224095 discloses a first component composed of a polyester resin and a second polyolefin resin having a melting point of 20 ° C. or lower than the melting point of the polyester resin. A thermal bonding conjugate fiber having crimps composed of components, and as an index of stabilization of the crimp shape, when the thermally adhesive composite fiber is made of a web, the bulk retention after heat treatment of the web A heat-adhesive composite fiber is disclosed which has a bulk retention rate of 20% or more. Heat-sealed composite fibers, which are used as a material for manufacturing nonwoven fabrics, are generally of a herbicidal type in which heterogeneous components are compatible with each other. The composite fiber of Korea Patent Publication No. 10-1224095 has a core part made of polyester resin and the sheath part is made of polyolefin resin. At this time, the interface between the core part and the sheath part is inferior in adhesive strength due to heterogeneous components, and the interface is peeled off. Occurs. Interfacial delamination between the core and the sheath that occurs in a deep sheath composite fiber may make subsequent nonwoven processability difficult or cause poor quality of the nonwoven product (eg, roughening). Therefore, there is a need for the development of a heat-sealable composite fiber having excellent bulk properties and at the same time minimizing the interfacial separation between the core and the core.

The present invention has been drawn under such a background, and an object of the present invention is to provide a heat-sealable composite fiber having a good spinning property in a manufacturing step, an excellent bulk property, and minimizing interfacial delamination between core parts and initial parts, and a method of manufacturing the same. It is in It is also an object of the present invention to provide a heat-sealable composite fiber and a method for producing the same, which are excellent in processability to nonwoven fabrics and can impart excellent physical properties to nonwoven fabrics.

In addition, another object of the present invention is to provide a nonwoven fabric having excellent tensile strength and bulk properties as a heat-sealable composite fiber.

The inventors of the present invention, in order to obtain good results in both the spinning, the physical properties of the prepared composite fiber, the workability in the step of manufacturing the nonwoven fabric using the composite fiber and the physical properties of the manufactured nonwoven fabric Recognizing that various parameters need to be adjusted, such as types of components constituting the core and their content ratios, types and contents of components constituting the core, weight ratio of core and core in the composite fiber, elongation at break of the composite fiber, etc. The present invention was completed through numerous experiments.

In order to achieve the object of the present invention, the present invention is a core containing a polyester-based resin and inorganic fine particles and a polyolefin-based resin and inorganic having a melting point 10 ℃ or more lower than the polyester-based resin constituting the core A composite fiber composed of sheath comprising fine particles, wherein the weight ratio of core to core in the composite fiber is 55:45 to 65:35, and the content of inorganic fine particles in the core is 100 parts by weight of the polyester resin. 0.5 to 5 parts by weight, the content of the inorganic fine particles in the sheath portion is 0.1 to 1.5 parts by weight per 100 parts by weight of polyolefin resin, the elongation at break of the composite fiber (elongation at break) characterized in that the heat is 30 to 80% Provides a fusible cardiac composite fiber. At this time, the polyester resin constituting the core is preferably characterized in that the melting point is 220 ~ 280 ℃, more preferably selected from polyethylene terephthalate (polyethylene terephthalate) or polytrimethylene terephthalate (polytrimethylene terephthalate) Can be. In addition, the polyolefin resin constituting the initial portion may preferably be selected from high density polyethylene, straight chain low density polyethylene or polypropylene. In addition, the inorganic fine particles constituting the core portion or the second portion are preferably titanium dioxide. At this time, the content of the titanium dioxide in the core is preferably characterized in that 1 to 4 parts by weight per 100 parts by weight of the polyester resin.

In addition, in order to achieve the object of the present invention, the present invention is a first composition comprising a polyester-based resin and inorganic fine particles is disposed in the core portion and has a melting point 10 ℃ or more lower than the polyester resin constituting the core portion Supplying a second composition comprising a polyolefin-based resin and inorganic fine particles to the core sheath spinneret so as to be disposed at the beginning to melt spinning to form an unstretched composite fiber; Stretching the unstretched composite fiber at a temperature higher than or equal to the glass transition temperature of the polyester resin constituting the core portion to a temperature lower than 10 ° C. below the melting temperature of the polyolefin resin constituting the initial portion to form the stretched composite fiber; And imparting crimp to the stretched composite fiber, followed by heat treatment, wherein the weight ratio of core portion to core portion in the composite fiber is 55:45 to 65:35, and the content of inorganic fine particles in the core portion is polyester resin. 0.5 to 5 parts by weight per 100 parts by weight, the content of the inorganic fine particles in the sheath portion is 0.1 to 1.5 parts by weight per 100 parts by weight of polyolefin resin, the elongation at break of the heat-treated composite fibers (30) It provides a method for producing a heat-sealing cardiac composite fiber, characterized in that 80%. At this time, the polyester resin constituting the core is preferably characterized in that the melting point is 220 ~ 280 ℃, more preferably selected from polyethylene terephthalate (polyethylene terephthalate) or polytrimethylene terephthalate (polytrimethylene terephthalate) Can be. In addition, the polyolefin resin constituting the initial portion may preferably be selected from high density polyethylene, straight chain low density polyethylene or polypropylene. In addition, the inorganic fine particles constituting the core portion or the second portion are preferably titanium dioxide. At this time, the content of the titanium dioxide in the core is preferably characterized in that 1 to 4 parts by weight per 100 parts by weight of the polyester resin. Further, the stretching temperature of the unstretched composite fiber is preferably 70 to 110 ° C, and the stretching ratio is preferably 2.5 to 3.5. Further, the heat treatment temperature of the crimped composite fiber is preferably 80 to 120 ° C.

In addition, in order to achieve another object of the present invention, the present invention provides a nonwoven fabric formed by thermal fusion of the composite fiber described above or the composite fiber produced by the above-described manufacturing method. At this time, the thermal fusion of the composite fiber is preferably characterized in that it is performed by a through-air boning method (calender bonding).

The heat-sealable sheath-type composite fiber according to the present invention has good spinning properties during melt spinning and hardly occurs interfacial peeling phenomenon between the core and the core. In addition, when the nonwoven fabric is manufactured from the heat-sealing cardiac composite fiber according to the present invention, web formation is good and dust is hardly generated. In addition, the nonwoven fabric made of the heat-sealing cardiac composite fiber according to the present invention has excellent bulk and tensile strength.

1 shows the types and chemical structures of aliphatic polyester resins.
2 shows the types and physical properties of various polyester resins.
3 is a photograph taken with a scanning electron microscope (SEM) of the cross-section of the heart sheath composite fiber prepared in Comparative Preparation Example 1, Figure 4 is a scanning electron microscope (SEM) a cross section of the heart sheath composite fiber prepared in Preparation Example 1 This picture was taken with).

Hereinafter, the present invention will be described in detail.

The heat-sealable core sheath composite fiber of the present invention comprises a core containing a polyester-based resin and inorganic fine particles and a polyolefin-based resin and inorganic fine particles having a melting point of 10 ° C. or lower than that of the polyester-based resin constituting the core. It consists of a sheath containing. In the myocardial composite fibers, the sheath is arranged in a shape surrounding the core. On the other hand, it is preferable that the weight ratio of core part to initial part in the said composite fiber is 55: 45-65: 35. When the total weight of the core part and the core part in the composite fiber is 100, the heat sealability of the nonwoven fabric is improved when the core weight is less than 55, but the bulk property may not be sufficient, and when the core weight exceeds 65, the bulk property is improved. But there is a risk of poor adhesion. In addition, the content of the inorganic fine particles in the core portion is 0.5 to 5 parts by weight per 100 parts by weight of the polyester resin, the content of the inorganic fine particles in the sheath portion is preferably 0.1 to 1.5 parts by weight per 100 parts by weight of the polyolefin resin. In general, the inorganic fine particles contained in the fiber serves to improve the whiteness of the nonwoven fabric made of the fiber, the inventors of the present invention when adjusting the content of the inorganic fine particles contained in the core and the beginning to the appropriate level in We found that the interface between the core and the core can be minimized. In addition, it is preferable that the elongated elongation at break is 30 to 80%. If the elongation at break of the sheath sheath type fiber is less than 30%, the frequency of trimming of the unstretched fiber increases during the stretching process, and there is a concern that the interfacial peeling between the core and the sheath may be deepened. In addition, when the elongation at break of the core sheath composite fiber exceeds 80%, the interfacial peeling phenomenon between the core and the core can be reduced, but the stretch orientation of the polyester resin constituting the core is insufficient, resulting in poor bulk properties of the nonwoven fabric. There is a risk of breaking.

The polyester resin which comprises the core part of the heat-sealable composite fiber of this invention can be generally obtained by diol and dicarboxylic acid polycondensation reaction. Examples of the dicarboxylic acid used for the polycondensation reaction of the polyester resin include terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, sebacic acid, and the like. In addition, as a diol used for the polycondensation reaction of polyester resin, ethylene glycol, diethylene glycol, 1, 3- propanediol, 1, 4- butanediol, neopentyl glycol, 1, 4- cyclohexane dimethanol, etc. are mentioned. Can be mentioned. As the polyester resin used in the present invention, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate can be preferably used. In addition to the aromatic polyesters, aliphatic polyesters may also be used, and polylactic acid and polybutylene adipate terephthalate may be mentioned as preferred resins. 1 shows the types and chemical structures of aliphatic polyester resins usable in the present invention. These polyester resins may be not only homopolymerized polyester but also copolyester (copolyester). At this time, as a copolymerization component, dicarboxylic acid components, such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diol components, such as diethylene glycol and neopentyl glycol, and optical isomers, such as L-lactic acid, Can be used. Two or more of these polyester resins may be used in combination. The polyester resin constituting the core portion of the above-described various polyester resins is polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate in consideration of its physical properties. (PEN), polyethylene terephthalate glycol (PETG) and polycyclohexanedimethylene terephthalate (PCT) may be selected from one or more, and polyethylene terephthalate (polyethylene terephthalate) or polytrimethylene terephthalate (polytrimethylene terephthalate ) Is preferably selected, and it is most preferable that the polyethylene terephthalate (Intrinsic viscosity, Iv) is 0.6 ~ 0.7 dl / g. 2 shows the types and physical properties of various polyester resins. Referring to Figure 2, it is preferable that the melting point of the polyester-based resin constituting the core portion is 220 ~ 280 ℃.

The polyolefin resin constituting the initial portion of the heat-sealable composite fiber of the present invention is a high-density polyethylene, linear low-density polyethylene, low-density polyethylene, polypropylene (propylene homopolymer), propylene-based ethylene-propylene copolymer, propylene Ethylenepropylenebutene-1 copolymer, polybutene-1, polyhexene-1, polyoctene-1, poly 4-methylpentene-1, polymethylpentene, 1,2-polybutadiene, 1,4-poly as a main component Butadiene, maleic anhydride modified product of ethylene polymer, maleic anhydride modified product of propylene polymer, etc. can be used. Moreover, these homopolymers may contain a small amount of α-olefins such as ethylene, butene-1, hexene-1, octene-1, or 4-methylpentene-1 other than the monomers constituting the homopolymer as a copolymerization component. Moreover, other ethylenically unsaturated monomers, such as butadiene, isoprene, 1, 3-pentadiene, styrene, and (alpha) -methylstyrene, may be contained in small quantities as a copolymerization component. Moreover, 2 or more types of said polyolefin resin can also be mixed and used. These can preferably use not only the polyolefin resin superposed | polymerized from the normal Ziegler-Natta catalyst but the polyolefin resin superposed | polymerized from a metallocene catalyst and their copolymers. Further, the melt flow index (MFI) of the polyolefin resin which can be used as the first component of the present invention is not particularly limited as long as it is a spinnable range, and it is preferably 1 to 100 g / 10 minutes, preferably 10 to 40 g / 10 minutes. desirable. Among the above-mentioned various polyolefin resins, the polyolefin resin constituting the first part is selected from high density polyethylene, linear low density polyethylene or polypropylene in consideration of various physical properties such as melting point difference and melt flow index (MFI) and the like. It is preferable that it is high density polyethylene.

In the heat-sealing cardiac composite fiber of the present invention, preferred combinations of the resin constituting the core and the resin constituting the core are polypropylene / polyethylene terephthalate, high density polyethylene / polyethylene terephthalate, and linear low density polyethylene / polyethylene terephthalate. Phthalate, low density polyethylene / polyethylene terephthalate can be illustrated. In addition to polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid may also be used.

The heat-sealing cardiac composite fiber of the present invention contains inorganic fine particles in both the core and the core. In this case, the content of the inorganic fine particles in the core portion is preferably 0.5 to 5 parts by weight per 100 parts by weight of the polyester resin, the content of the inorganic fine particles in the sheath portion is preferably 0.1 to 1.5 parts by weight per 100 parts by weight of the polyolefin resin. . When the content of the inorganic fine particles in the sheath in the heat-sealable sheath type composite fiber of the present invention is less than 0.1 parts by weight per 100 parts by weight of the polyolefin resin, the effect of minimizing the interfacial peeling of the core and the sheath due to the addition of the inorganic fine particles is insufficient, and the weight is 1.5 weight. In the case of excess part, there is a risk of poor radioactivity during fusion spinning and deterioration of workability due to generation of dust in the nonwoven fabric manufacturing step. The inorganic fine particles used in the heat-sealable sheath type composite fiber of the present invention are not particularly limited as long as they are compatible with the resin of the core and the resin of the core and have a function of suppressing the interfacial separation of the core and the core. For example, titanium dioxide, calcium carbonate, zinc oxide, barium titanate, barium carbonate, barium sulfate, zirconium oxide, zirconium silicate, alumina, magnesium oxide, silicon dioxide, cobalt, and the like, preferably titanium dioxide and zinc oxide, It is more preferable that it is titanium dioxide, considering the compatibility with the resin which comprises a core part and a sheath part, the effect of suppressing the interface peeling of a core part and a sheath part, etc. When using titanium dioxide as the inorganic fine particles, the content of titanium dioxide in the core is preferably 1 to 4 parts by weight per 100 parts by weight of the polyester resin. In addition, in consideration of the dispersibility and the radioactivity in melt extrusion with the polyolefin resin, the polyester resin and the polyolefin resin, the titanium dioxide preferably has an average particle size of 0.4 µm or less, and the narrower the particle size distribution, the better. Titanium dioxide is divided into rutile type, anatase type, and brookite type depending on the crystal, and one of them or a mixture thereof can be used.

The cross-sectional shape of the heat sealable composite fiber according to the present invention is generally circular, but the cross-section of the core or sheath may be a hetero-shaped cross-sectional shape (non-circular cross-sectional shape), for example, star, oval, triangle, square, It may be a pentagonal, multileafed, arrayed, special character type such as X, Y, T, etc., horseshoe type, or irregular cross-sectional shape. Further, in the heat-sealable composite fiber according to the present invention, the core portion may be arranged concentrically at the beginning or eccentrically. In addition, a hollow may be formed in the core portion. According to the selection of the cross-sectional shape of the composite fiber, it is possible to variously adjust the bulk properties, absorption characteristics and the like of the nonwoven fabric. For example, when the cross section of the composite fiber is manufactured in a non-circular shape, light is diffusely reflected to improve covering or uniformity of the nonwoven fabric. In addition, when giving a hollow to a core part, weight reduction and bulkiness of a nonwoven fabric can be improved.

According to the present invention, a method of manufacturing a heat-sealing heart-shaped composite fiber has a melting point of 10 ° C. or lower than that of a polyester-based resin comprising a polyester-based resin and a first composition including inorganic fine particles disposed at a core thereof and constituting the core. Supplying a second composition comprising a polyolefin-based resin and inorganic fine particles to the core sheath spinneret so as to be disposed at the beginning to melt spinning to form an unstretched composite fiber; Stretching the unstretched composite fiber at a temperature higher than or equal to the glass transition temperature of the polyester resin constituting the core portion to a temperature lower than 10 ° C. below the melting temperature of the polyolefin resin constituting the initial portion to form the stretched composite fiber; And heat treatment after imparting crimp to the stretched composite fiber. At this time, the weight ratio of the core portion to the core portion in the composite fiber is 55:45 to 65:35, the content of the inorganic fine particles in the core portion is 0.5 to 5 parts by weight per 100 parts by weight of the polyester resin, the inorganic fine particles in the sheath The content of is 0.1 to 1.5 parts by weight per 100 parts by weight of the polyolefin resin, the elongation at break of the heat-treated composite fibers (elongation at break) is preferably 30 to 80%.

In the method for manufacturing a heat-sealing heart-shaped composite fiber according to the present invention, the first composition containing a polyester-based resin and inorganic fine particles or the second composition containing a polyolefin-based resin and inorganic fine particles may be prepared by various methods. . For example, in the step of polymerizing the resin of the core portion or the resin of the initial portion, the inorganic fine particles may be mixed at a predetermined ratio, and may be prepared. The inorganic fine particles may be masterbatched and mixed immediately before melt spinning.

The stretching step in the manufacturing method of the heat-sealing cardiac composite fiber according to the present invention is made in a specific temperature range, the preferred stretching temperature range is 70 ~ 110 ℃. Moreover, it is preferable that a draw ratio is 2.5-3.5. In the method for producing a heat-sealing composite vinegar composite fiber according to the present invention, when the unstretched composite fiber is stretched at or below the glass transition temperature of the polyester resin, the stretching characteristics of the core portion and the core portion become too different, and the interface separation between the core portion and the edge portion is performed. The phenomenon can be enhanced. In addition, when the unstretched composite fiber is stretched at a temperature higher than the melting temperature of the polyolefin resin-10 ° C, there is a fear that the superstructure melts during the stretching process and loses its original shape. In the present invention, the unoriented composite fibers undergo some orientation and crystallization by a drawing process. In addition, the stretched composite fiber is further subjected to crystallization by heat treatment after the crimp is applied, wherein the heat treatment temperature is preferably 80 ~ 120 ℃.

The heat-sealable poncho composite fiber according to the present invention can maintain the shape stability of the crimp even when heat-bonded, and has excellent flexibility in bulk as well as tensile strength, so that a net, web, knitted fabric, nonwoven fabric, etc. can be used as a manufacturing material. It can be used as a manufacturing material of the nonwoven fabric. As a method for bonding the composite fibers when the heat-sealing edible-type composite fibers according to the present invention are processed into a nonwoven fabric, various known methods such as thermal bonding, airlaid, needle punching, and waterjet methods are known. Can be used. In consideration of the thermal adhesion of the myocardial composite fibers according to the present invention, it is preferable to use thermal bonding, for example, through-air boning or calender bonding. bonding).

Examples of the fibrous product using the heat-sealable composite fiber of the present invention or the nonwoven fabric prepared therefrom include absorbent articles such as diapers, inner skins, incontinence pads, sanitary napkins, medical hygiene materials such as gowns, surgical garments, wall sheets, window papers, and flooring materials. Interior materials, covering cloth, cleaning wiper, living materials such as cover for food waste, bathroom products such as disposable toilet paper, toilet cover, pet sheet, pet diapers, pet towels, etc. Wiping materials, filters, cushioning materials, oil adsorption materials, industrial materials such as ink tank adsorption materials, general medical materials, bedding materials, nursing supplies and the like, but is not limited thereto.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to clearly illustrate the technical features of the present invention, and do not limit the scope of protection of the present invention.

1. Explanation of analysis method

(1) Radioactivity: The number of times of trimming, drop, etc. occurring during 1 hr when forming an unstretched composite fiber by composite spinning was measured, and evaluated by dividing it into S to D grades. The evaluation criteria for each grade are as follows.

S: 0 times; A: once; B: 2-3 times; C: 4-6 times; D: 7 or more times

(2) Composite fiber fineness: It measured based on ASTMD1577.

(3) Composite Fiber Tensile Strength and Elongation at Break: The tensile properties of the composite fibers were measured according to ASTM D3822.

(4) Deep / superficial interfacial delamination state of the deep sheath type composite fiber: The deep sheath type composite fiber obtained through stretching, crimping, and heat treatment after complex spinning was put in liquid nitrogen, removed, and cut in the longitudinal direction. Then, the cross section of the composite fiber was photographed with a scanning electron microscope (SEM), and the evaluation was performed based on the ratio of the fibers having a peeling interval of 0.4 μm or more at the center and the beginning of the 30 fibers. Specific evaluation criteria are as follows.

S: less than 10%; A: 11-20%; B: 21-30%; C: 31-40%; D: 41% or more

(3) Degree of web formation in nonwoven fabric manufacturing: 5 professional panels were visually observed and classified into D grades in S.

S: very good web formation; A: good web formation; B: web formation usually; C: poor web formation; D: very bad web formation

(4) Degree of dust generation during nonwoven fabric manufacturing: Non-woven fabric with a basis weight of about 20 g / m2 is produced by thermally fusion-bonding fibers on the web by through-air boning while winding the web at a speed of 80 m / min. When the amount of dust dropped under the carding machine and the oven belt was visually confirmed, it was evaluated by dividing it into S to D grade. The evaluation criteria for each grade are as follows.

S: almost none; A: small amount of occurrence; B: moderately occurring; C: occurs a lot; D: very often

(5) Nonwoven basis weight: The basis weight of the nonwoven fabric was measured according to the ERT method (EDANA RECOMMENDED TEST METHODS) 40.3-90.

(6) Nonwoven Thickness: The thickness of the nonwoven fabric was measured according to the ERT method (EDANA RECOMMENDED TEST METHODS) 30.5-99.

(7) Non-woven fabric tensile strength: The tensile strength of the nonwoven fabric is determined by the ERT method (EDANA RECOMMENDED TEST METHODS) 20.2-89, the longitudinal tensile strength of the nonwoven fabric (hereinafter referred to as "MD tensile strength") and the transverse tensile strength of the nonwoven fabric. (Hereinafter referred to as "CD tensile strength") was measured.

2. Heart-shaped  Preparation of Composite Fiber

The core component and the core component were melt-extruded at a predetermined weight ratio through separate extruders, and fed to the core sheath-type spinneret, followed by complex spinning to form unstretched composite fibers. Thereafter, the surface of the unstretched composite fiber was stretched while being treated with a hydrophilic spinning oil in an amount of 0.5% by weight of the composite fiber. Thereafter, the stretched composite fibers were crimped, and then heat-treated at a predetermined temperature in a hot air dryer. The heat treated composite fiber was cut to a length of about 40 mm to obtain a deep sheath type composite short fiber. Tables 1 and 2 show the materials and process conditions used for each composite short fiber preparation.

Comparative Production Example Core Sheath Weight ratio of core and core Composite Fiber Manufacturing Conditions Suzy TiO ₂ added amount (%) Extrusion temperature (℃) Suzy TiO ₂ added amount (%) Extrusion temperature (℃) Deep First Radiated fineness (De ') Stretching temperature Draw ratio Heat treatment temperature (℃) One PET 0.3 290 HDPE 0.0 235 60 40 4.85 65 2.65 100 2 PET 0.0 290 HDPE 0.0 235 45 55 4.82 85 2.65 100 3 PET 4.0 290 HDPE 0.4 235 40 60 4.90 65 2.65 100 4 PET 0.0 290 HDPE 0.0 235 60 40 4.80 85 2.65 100 5 PET 4.0 290 HDPE 0.2 235 70 30 4.84 85 2.65 100 6 PP 2.0 260 HDPE 0.4 235 60 40 6.65 95 4.35 100 7 PET 2.0 290 HDPE 0.0 235 60 40 4.85 85 2.65 100 8 PET 4.0 290 HDPE 4.0 235 60 40 4.85 85 2.65 100 9 PET 0.0 290 HDPE 1.0 235 60 40 4.80 85 2.65 100 10 PET 2.0 290 HDPE 0.05 235 50 50 3.65 85 2.00 100 11 PET 2.0 290 HDPE 0.05 235 60 40 4.81 120 2.65 100 12 PET 4.0 290 HDPE 0.4 235 50 50 4.90 85 2.70 100 13 PET 4.0 290 HDPE 0.1 235 60 40 4.20 85 2.20 100 14 PET 4.0 290 HDPE 0.05 235 60 40 6.15 110 3.20 100 15 PTT 4.0 290 HDPE 0.05 235 60 40 4.80 70 2.70 100

Manufacturing Example Core Sheath Weight ratio of core and core Composite Fiber Manufacturing Conditions Suzy TiO ₂ added amount (%) Extrusion temperature (℃) Suzy TiO ₂ added amount (%) Extrusion temperature (℃) Deep First Radiated fineness (De ') Stretching temperature Draw ratio Heat treatment temperature (℃) One PET 4.0 290 HDPE 0.4 235 60 40 4.88 85 2.65 100 2 PET 1.0 290 HDPE 0.1 235 55 45 4.95 90 2.80 100 3 PET 4.0 290 HDPE 0.4 235 65 35 4.80 85 2.65 100 4 PET 1.5 290 HDPE 1.5 235 60 40 4.82 85 2.65 100 5 PET 4.0 290 HDPE 0.4 235 55 45 4.91 85 2.65 100 6 PET 4.0 290 HDPE 0.1 235 60 40 4.26 85 2.24 100 7 PET 4.0 290 HDPE 0.1 235 60 40 6.12 110 2.98 100 8 PTT 4.0 290 HDPE 0.1 235 60 40 4.82 70 2.68 100

Abbreviations and additional descriptions used in Table 1 and Table 2 are as follows.

* PET (Polyethylene terephthalate): Intrinsic viscosity (Iv) is 0.663 ㎗ / g, specific gravity is 1.38, melting point is 256 ℃, glass transition temperature is 75 ~ 80 ℃

* PTT (Polytrimethylene terephthalate): Intrinsic viscosity (Iv) is 0.9 ㎗ / g, specific gravity is 1.33, melting point is 228 ℃ and glass transition temperature is 45 ~ 65 ℃

* HDPE (High Density Polyethylene): The melt flow index (MFI) measured at 190 ℃ and 2.16kg load conditions according to ASTM D1238 is 17.0 / 10 minutes, specific gravity is 0.95, melting point is 129 ℃, and glass transition temperature is -100 ℃ or less

* PP (Polypropylene): Melt Flow Index (MFI) measured at 230 ℃ and 2.16kg load condition according to ASTM D1238, 25.0 / 10 minutes, specific gravity 0.9, melting point 162 ℃, glass transition temperature -16 ~ -20 ℃

In addition, Table 1, and TiO ₂ amount added of the core in Table 2, and 100 parts by weight of the resin constituting the core by weight percent, based on, TiO ₂ amount of the sheath is the weight of 100 parts by weight of the resin constituting the sheath by %being

HDPE constituting the first part in Table 1 can be replaced with LLDPE (linear low density polyethylene). LLDPE generally has a melt flow index (MFI) of 16.2 / 10 minutes, specific gravity of 0.924, melting point of 115.9 ° C, and glass transition temperature of -100 ° C, measured at 190 ° C and 2.16kg under load conditions in accordance with ASTM D1238. Hereinafter, it has similar physical properties to HDPE.

3. Heart-shaped  Evaluation of Physical Properties of Composite Fibers

In Comparative Examples 1 to 15 and Preparation Examples 1 to 8, the spinning properties and the fineness, tensile strength, elongation at break and deep / superficial interfacial peeling state of the prepared composite fibers were evaluated. It is shown in Table 3 below.

Composite fiber separator Radioactive Composite Fiber Fineness (De ') Composite Fiber Tensile Strength (g / De ') Composite Fiber Break Elongation (%) Composite Fiber Core / Super Interfacial Peeling State Comparative Preparation Example 1 S 2.16 3.75 52 D Comparative Production Example 2 S 2.15 3.22 61 D Comparative Production Example 3 A 2.18 2.92 70 C Comparative Production Example 4 S 2.14 3.56 41 C Comparative Preparation Example 5 A 2.16 3.93 45 A Comparative Preparation Example 6 S 2.14 3.36 127 S Comparative Preparation Example 7 S 2.16 3.75 52 B Comparative Preparation Example 8 C 2.10 3.56 49 A Comparative Production Example 9 A 2.08 3.64 54 C Comparative Production Example 10 C 2.15 2.43 121 S Comparative Production Example 11 A Melting at the drawing stage melts the final composite fibers Comparative Production Example 12 A 2.14 3.45 42 A Comparative Production Example 13 A 2.15 2.88 90 S Comparative Production Example 14 S 2.27 4.21 35 B Comparative Production Example 15 A 2.10 3.30 51 B Production Example 1 S 2.17 3.48 54 S Production Example 2 S 2.09 3.60 40 S Production Example 3 A 2.14 3.95 52 A Production Example 4 A 2.10 3.44 47 S Production Example 5 A 2.15 3.48 41 A Production Example 6 A 2.14 3.12 80 S Production Example 7 S 2.25 4.11 34 A Production Example 8 A 2.13 3.33 50 A

3 is a photograph taken with a scanning electron microscope (SEM) of the cross-section of the heart sheath composite fiber prepared in Comparative Preparation Example 1, Figure 4 is a scanning electron microscope (SEM) a cross section of the heart sheath composite fiber prepared in Preparation Example 1 This picture was taken with). As shown in FIGS. 3 to 4, the core sheath-type composite fiber prepared in Comparative Preparation Example 1 is very severe in the core / secondary interface peeling, whereas the core sheath-type composite fiber prepared in Preparation Example 1 does not generate the core / secondary interface peeling. Did.

4. Fabrication and Properties Evaluation of Nonwovens

Nonwoven fabrics were prepared using the composite short fibers prepared in Comparative Preparation Examples 1 to 10, Comparative Preparation Examples 12 to 15, and Preparation Examples 1 to 8. Specifically, the composite short fibers are carded in a card at a speed of 80 m / min to produce a web of a certain basis weight, the non-woven fabric was manufactured by heat-sealing the web by the through-air boning method (through-air boning). When the through-air boning was applied, the winding speed of the web was 80 m / min, the temperature of the belt dryer was 140 ° C, and the residence time of the dryer of the web was 7 seconds. The workability and the various physical properties of the final nonwoven fabric when the nonwoven fabric was manufactured with the composite short fibers were evaluated, and the results are shown in Table 4 below. In Table 4, the thickness of the nonwoven fabric is interpreted as the bulk property of the nonwoven fabric.

Classification of Composite Fibers Used in Nonwoven Fabrics Workability in nonwoven fabric manufacturing Properties of Final Nonwovens Degree of web formation Dust generation degree Basis weight (g / ㎡) Thickness (mm) MD tensile strength
(Kg / 5 cm) CD tensile strength
(Kg / 5 cm) Comparative Preparation Example 1 A D 20.3 1.42 2.54 0.65 Comparative Production Example 2 B C 20.5 0.92 2.35 0.60 Comparative Production Example 3 B C 20.5 0.83 2.12 0.55 Comparative Production Example 4 A C 20.0 1.40 2.67 0.60 Comparative Preparation Example 5 S A 20.0 1.48 1.73 0.42 Comparative Preparation Example 6 A A 20.5 0.80 2.28 0.47 Comparative Preparation Example 7 A B 20.2 1.44 2.66 0.61 Comparative Preparation Example 8 A B 19.8 1.34 2.48 0.56 Comparative Production Example 9 A C 20.3 1.45 2.58 0.58 Comparative Production Example 10 B A 20.1 0.95 2.63 0.63 Comparative Production Example 12 S A 21.0 1.22 2.89 0.78 Comparative Production Example 13 S S 20.2 1.27 2.70 0.71 Comparative Production Example 14 A C 20.5 1.64 2.75 0.73 Comparative Production Example 15 A A 20.0 1.25 2.56 0.60 Production Example 1 S S 20.1 1.60 2.82 0.72 Production Example 2 S S 20.7 1.51 2.77 0.70 Production Example 3 S A 20.5 1.65 2.52 0.52 Production Example 4 S A 20.4 1.54 2.77 0.70 Production Example 5 S A 20.7 1.49 2.84 0.76 Production Example 6 S S 20.1 1.50 2.71 0.73 Production Example 7 A A 20.2 1.62 2.74 0.72 Production Example 8 A A 20.1 1.48 2.57 0.69

As shown in Table 1 to Table 4 when manufacturing the heart sheath type composite fiber according to Comparative Preparation Example 1 to Comparative Production Example 15 and a nonwoven fabric therefrom to produce a deep sheath type composite fiber by composite spinning the core component and the core component Good results were not obtained in the steps, the physical properties of the prepared composite fiber, the step of preparing the nonwoven fabric using the composite fiber, and the physical properties of the manufactured nonwoven fabric. Table 5 summarizes the problems arising when manufacturing the sheath type composite fiber according to Comparative Production Example 1 to Comparative Production Example 15 and manufacturing a nonwoven fabric therefrom. In addition, although not shown in Table 4, when the nonwoven fabric is manufactured from a composite fiber having a poor core / secondary interface peeling state, a roughing phenomenon occurs in which the surface of the nonwoven fabric is rough.

Composite fiber separator Composite Fiber Manufacturing Step Issues Composite Fiber Property Issues Nonwoven Fabrication Step Problems Nonwoven Property Problems Comparative Preparation Example 1 Deep / Super Interfacial Peel Status Dust generation degree Comparative Production Example 2 Deep / Super Interfacial Peel Status Web formation degree, dust generation degree Thickness (Bulkness) Comparative Production Example 3 Deep / Super Interfacial Peel Status Web formation degree, dust generation degree Thickness (Bulkness) Comparative Production Example 4 Deep / Super Interfacial Peel Status Dust generation degree Comparative Preparation Example 5 The tensile strength Comparative Preparation Example 6 Thickness (Bulkness) Comparative Preparation Example 7 Deep / Super Interfacial Peel Status Dust generation degree Comparative Preparation Example 8 Radioactive Dust generation degree Thickness (Bulkness) Comparative Production Example 9 Deep / Super Interfacial Peel Status Dust generation degree Comparative Production Example 10 Radioactive Degree of web formation Thickness (Bulkness) Comparative Production Example 11 Composite fiber cannot be manufactured Comparative Production Example 12 Thickness (Bulkness) Comparative Production Example 13 Thickness (Bulkness) Comparative Production Example 14 Deep / Super Interfacial Peel Status Dust generation degree Comparative Production Example 15 Deep / Super Interfacial Peel Status Thickness (Bulkness)

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the protection scope of the present invention should be construed as including all embodiments falling within the scope of the claims appended to the present invention.

Claims (16)

A composite fiber comprising a core containing a polyester resin and inorganic fine particles and a polyolefin resin having a melting point of 10 ° C. or lower than the polyester resin constituting the core and a sheath including inorganic fine particles. ,
The weight ratio of core to sheath in the composite fiber is 55:45 to 65:35,
The content of the inorganic fine particles in the core portion is 1 to 4 parts by weight per 100 parts by weight of the polyester resin,
The content of the inorganic fine particles in the chobu portion is 0.1 to 1.5 parts by weight per 100 parts by weight of the polyolefin resin,
The weight ratio of the inorganic fine particles contained in the core to the inorganic fine particles contained in the core portion is 1: 1 to 1: 0.025,
A heat-sealing cardiac composite fiber, wherein the elongation at break of the composite fiber is 34 to 80%.
The heat-sealing cardiac composite fiber according to claim 1, wherein the polyester resin constituting the core portion has a melting point of 220 to 280 ° C.
The heat-sealing cardiac composite fiber of claim 2, wherein the polyester resin is selected from polyethylene terephthalate or polytrimethylene terephthalate.
The heat-sealing cardiac composite fiber according to claim 1, wherein the polyolefin-based resin constituting the sheath portion is selected from high density polyethylene, straight chain low density polyethylene or polypropylene.
The heat-sealing cardiac composite fiber according to claim 1, wherein the inorganic fine particles are titanium dioxide.
6. The fusible tachycardia composite fiber according to claim 5, wherein the content of titanium dioxide in the sheath portion is 0.1 to 0.4 parts by weight per 100 parts by weight of the polyolefin resin.
A first composition comprising a polyester resin and inorganic fine particles is disposed in the core, and a second composition containing a polyolefin resin and inorganic fine particles having a melting point of 10 ° C. or lower than the polyester resin constituting the core is included in the core. Supplying to the deep sheath spinneret to be disposed and then melt spinning to form an unstretched composite fiber;
Stretching the unstretched composite fiber at a temperature higher than or equal to the glass transition temperature of the polyester resin constituting the core portion to a temperature lower than 10 ° C. below the melting temperature of the polyolefin resin constituting the initial portion to form the stretched composite fiber; And
Imparting crimp to the stretched composite fiber, followed by heat treatment,
The weight ratio of core to sheath in the composite fiber is 55:45 to 65:35,
The content of the inorganic fine particles in the core portion is 1 to 4 parts by weight per 100 parts by weight of the polyester resin,
The content of the inorganic fine particles in the chobu portion is 0.1 to 1.5 parts by weight per 100 parts by weight of the polyolefin resin,
The weight ratio of the inorganic fine particles contained in the core to the inorganic fine particles contained in the core portion is 1: 1 to 1: 0.025,
Elongation at break of the heat-treated composite fibers (elongation at break) is characterized in that the manufacturing method of the heat-sealing cardiac composite fiber.
8. The method for producing a heat-sealing cardiac composite fiber according to claim 7, wherein the polyester resin constituting the core portion has a melting point of 220 to 280 캜.
The method of claim 8, wherein the polyester-based resin is selected from polyethylene terephthalate or polytrimethylene terephthalate.
8. The method for producing a heat-sealed cardiac composite fiber according to claim 7, wherein the polyolefin-based resin constituting the sheath portion is selected from high density polyethylene, straight chain low density polyethylene or polypropylene.
8. The method for producing a heat-sealed cardiac composite fiber according to claim 7, wherein the inorganic fine particles are titanium dioxide.
The method of claim 11, wherein the content of titanium dioxide in the sheath portion is 0.1 to 0.4 parts by weight per 100 parts by weight of the polyolefin resin.
8. The method of claim 7, wherein the stretching temperature of the unstretched composite fiber is 70 to 110 ° C, and the draw ratio is 2.5 to 3.5.
8. The method for producing a heat-sealed cardiac composite fiber according to claim 7, wherein a heat treatment temperature of the crimped composite fiber is 80 to 120 ° C.
A nonwoven fabric formed by thermal fusion of a composite fiber according to any one of claims 1 to 6 or a composite fiber produced by the production method according to any one of claims 7 to 14.
The nonwoven fabric according to claim 15, wherein the thermal fusion of the composite fiber is performed by through-air boning or calender bonding.

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