Title of Invention	A MULTI-FILAMENT WITH EXCELLENT ABSORPTION-DRY PROPERTY AND ANTIBIOTIC PROPERTY
Abstract	The present invention discloses a multifilament having excellent antibacterial properties and sweat absorption and fast drying properties. The multifilament is characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a modified cross section in which six spherical protuberances, i.e., two on the top surface, two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (L1) of the cross section of the monofilaments, and (III) the multifilaments contains 0.3 to 2.0 % by weight of a silver-based inorganic antibacterial agent with silver (Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to1.0µm. -6 MAY 2008

Title of Invention

A MULTI-FILAMENT WITH EXCELLENT ABSORPTION-DRY PROPERTY AND ANTIBIOTIC PROPERTY

Abstract

The present invention discloses a multifilament having excellent antibacterial properties and sweat absorption and fast drying properties. The multifilament is characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a modified cross section in which six spherical protuberances, i.e., two on the top surface, two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (L1) of the cross section of the monofilaments, and (III) the multifilaments contains 0.3 to 2.0 % by weight of a silver-based inorganic antibacterial agent with silver (Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to1.0µm. -6 MAY 2008

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See section 10, Rule 13] A MULTI-FILAMENT WITH EXCELLENT ABSORPTION-DRY PROPERTY AND ANTIBIOTIC PROPERTY; KOLON INDUSTRIES, INC. A CORPORATION ORGANIZED AND EXISTING UNDER THE LAWS OF KOREA, WHOSE ADDRESS IS KOLON TOWER, 1-23, BYULYANG-DONG, KWACHEON-SI, KYUNGGI-DO 427-040, REPU BLIC OF KOREA. THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. TECHNICAL FIELD The present invention relates to yarn for apparel, and more particularly, to a multifilament which exhibit excellent sweat absorption properties as well as rapid drying of absorbed sweat (hereinafter, sweat absorption and fast drying properties') when used as yarn for sports apparel and which exhibit excellent suppression of the saturation and growth of bacteria that cause the discoloration and decolorization of fiber and are detrimental to human health (hereinafter, 'antibacterial properties'). BACKGROUND ART Recently, with the rise in the standard of living, the demand for clothes with various functions is increasing. In other words, there is a need for clothes with sweat absorption and fast drying properties as well as physical and chemical durability. Conventionally, cotton yarns or mixed yarns of cotton and polyester with good absorption have been commonly used as yarns for clothes. However, when subjected to heavy perspiration, the above-mentioned yarns absorb a great deal of sweat, and therefore they afford a wet and cold feeling and the clothes made from the yarn cling and stick to the body of the wearer. Moreover, fibers may be discolored or decolorized by bacteria or may produce foul odors, like sweat, when worn for a long time, in other words, antibiotic properties are insufficient. Meanwhile, U.S. Patent Application No. 4,470,407 discloses a polyester non-circular cross section fiber having a scalloped-oval cross section as shown in Fig. 4 in order to enhance the moisture diffusion of the fiber, and Korean Patent Laid-Open No. 1999-7736 discloses a non-circular cross section fiber with 3 to 5 spherical projections formed at equal intervals. The above-mentioned conventional non-circular cross section fibers have only 2 to 5 protuberances serving as a passage for dispersing sweat, and therefore they are inferior in sweat absorption and fast drying properties and comfort. Also they have no antibacterial properties. Meanwhile, Korean Patent Laid-Open No. 2002-71522 discloses a non-circular cross section fiber with six spherical protuberances formed symmetrically as shown in Fig. 2. The above-mentioned non-circular cross section fiber is excellent in sweat absorption and fast drying properties but is lacking in antibacterial properties. As a conventional technique for providing fiber with antibacterial properties, a method of providing antibacterial properties by immersing fabrics in an antibacterial agent solution has been used widely. In this case, however, the antibacterial function is lost after more than 10 washings, i.e., the washing resistance is low. 3 As another conventional technique for providing fiber with antibacterial properties, there have been used a method of copolymerizing a copolymer component comprising an antibacterially active substance in polymer resin that is a fiber material and a method of blending the polymer resin with a fine antibacterial agent and so on. As the antibacterial agent, a natural antibacterial agent such as chitosan or a silver based inorganic antibacterial agent or an antibacterial agent having a photocatalytic function is used, but an inorganic antibacterial agent which is highly resistant to high temperature spinning is more widely used. Although the aforementioned methods can provide antibacterial properties, they are inferior in washing resistance and cannot provide both sweat absorption and fast drying properties simultaneously. It is, therefore, an object of the present invention to overcome the above problems, and provide yarn (multifilament) which is excellent in both sweat absorption and fast drying properties and antibacterial properties. DISCLOSURE OF THE INVENTION TECHNOLOGICAL PROBLEM The present invention provides improved sweat absorption and rapid drying by forming the cross sections of monofilaments comprising yarn (multifilament) in a modified form in which six spherical 4 protuberances are symmetrically formed as shown in Fig. 2, and provides a multifilament with antibacterial properties without deteriorating workability by dispersing and containing a silver-based inorganic antibacterial agent (diameter: 0.1 to l.Ojum) with silver(Ag) substituted in zirconium phosphate. TECHNOLOGICAL SOLUTION To achieve the above objects, there is provided a multifilament according to the present invention, characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a non-circular cross section in which six spherical protuberances, that is, two on the top surface and two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (Li) of the cross section of the monofilaments, and (III) the multifilament contains 0.3 to 2.0% by weight of a silver-based inorganic antibacterial agent with silver(Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to 1.0im\. A preferred embodiment of the present invention will now be described with reference to the accompanying drawings. Firstly, the present invention relates to a multi-filament consisting of thermoplastic monofilaments. The cross section of the monofilament has six spherical protuberances of different sizes 5 symmetrically formed as shown in Fig 2. More specifically, the monofilaments have a cross section in which six spherical protuberances, i.e., two on the top surface, two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length(L1) of the cross section of the monofilaments. On the cross section of the monofilament, the ratio of the short axis length (L2) of the monofilament to the short axis width (Di) thereof [L2/D1] is 1.0 to 4.0. If the ratio of L2/D1 is less than 1.0, the sweat absorption and fast drying properties are degraded, if it exceeds 4.0, the sweat absorption and fast drying properties and the workability are degraded. In addition, it is preferred that the ratio of long axis length (L1) of monofilament to the short axis length (L2) of monofilament (L1/L2) is 1.0 to 4.0. Beyond this range, the workability and the sweat absorption and fast drying properties may be degraded. In the present invention, as thermoplastic resin, polyamide, polyester, polyacryl or the like can be used. More preferably, hydrophobic polyester is used as the thermoplastic resin. The multifilament (yarn) of the present invention has excellent sweat absorption properties because six protuberances of different sizes serve as a passage for rapidly discharging sweat from the body of a wearer to the surface of clothes. In addition, the non-multifilament (yarn) of the present invention exhibits a property of rapid evaporation 6 of sweat discharged to the surface of clothes in the air (rapid sweat drying property) because it has a very large surface area in contact with the air. Moreover, the multifilament (yarn) of the present invention prevents the phenomenon that clothes cling to the body even if a wearer perspires profusely because it has a small contact area with the body, thereby affording excellent comfot when worn. The multifilament (yarn) of the present invention can be mainly used in producing clothes such as jackets by using it alone or mixing it with cotton or polypropylene yarn. The multifilament (yarn) of the present invention contains 0.3 to 2.0% by weight, with respect to the total yarn weight, of a silver-based inorganic antibacterial agent having an average particle diameter of 0.1 to l.OjOTl. The aforementioned silver-based inorganic antibacterial agent is an antibacterial agent with silver substituted in zirconium phosphate (ZrO2P2O5), an inorganic carrier, that is to say, 'NOVARON®" manufactured by Toagosei Co. Ltd, Japan. The above silver-based inorganic antibacterial agent inhibits metabolic functions necessary for life support since silver ions act on bacteria, and destroys cell membranes of bacteria by generating active oxygen (O2) under the existence of water and light. If the average particle diameter of the silver-based inorganic 7 antibacterial agent exceeds l.0µm, it becomes difficult to produce fine yarn less than 2 deniers and the pressure of a spinning pack is sharply increased, thus deteriorating the workability (Full-Drum rate). If the average particle diameter is less than 0.1/µm, the dispersability of the antibacterial agent is poor, thus deteriorating the workability and increasing costs. If the content of the silver-based inorganic antibacterial agent in the yarn exceeds 2.0% by weight, the production costs become higher and the dispersability is lowered, thus deterioarting the workability. If less than 0.3% by weight, a sufficient antibacterial function cannot be obtained. The multifilament of the present invention can be produced through the process shown in Fig. 1. Fig. 1 is a schematic process chart illustrating the production of multifilament according to the present invention. Specifically, a thermoplastic polymer chip is supplied to an extruder 3 through a thermoplastic polymer chip feed pipe 1, and at the same time a thermoplastic polymer chip (hereinafter, 'master batch chip') to which a silver-based inorganic antibacterial agent has been added is supplied to the extruder 3 through a side feeder 2. Continuously, the thermoplastic polymer chip and the thermoplastic polymer chip (master batch chip) to which the silver-based inorganic antibacterial agent has been melted and mixed together in extruder 3. 8 Continuously, the melted polymer is melt-spun through a spinneret 4 having a cross section as shown in Fig. 3, cooled by a cooling chamber 5, drawn between a first godet roll 7 and a second godet roll 8 through a focusing guide 6, and is then wound by a take-up machine 9, thereby producing the multifilament of the present invention. Preferably, the temperature of the first godet roll 7 is about 85°C, and the rotational linear velocity thereof is about l,500m/min. Preferably, the temperature of the second godet roll 8 is about 123°C, and the rotational linear velocity thereof is about 4,300m/min. Preferably, the winding velocity of the take-up machine 9 is about 4,200m/min. In the present invention, however, the rotational linear velocity and temperature of the first godet roll 7, second godet roll 8 and take-up machine 9 are not specifically limited. At this time, it is more preferable to produce a master batch chip and then supply the master batch chip to the extruder 3 through the feeder 2 as shown above in terms of dispersability and workability, rather than to directly put the silver-based inorganic antibacterial agent into the extruder 3. The present invention has a full drum rate of more than 95% owing to excellence workability. The multifilament of the present invention has a bacteriostatic reduction rate of 99.00 to 99.99% and a bacteriostatic activity value of 2.2 to 6.3 as measured according to the KS K 0693-2001 method. Moreover, the multifilament of the present invention has an absorption rate of 100 to 185mm/10 min as measured by the Birack method (Wicking Test), and an absorption area of 8 to 14cm2/30sec as measured by a drop application method. Moreover, the multifilament of the present invention exhibits a drying time of 20 to 40 minutes for which the moisture of 0.05mC in the yarn is dried out. In the present invention, a variety of physical properties of the multifilament are evaluated as follows. ■ workability(F/D rate) The ratio of full drums to the total number of drums produced in a spinning process is obtained. • bacteriostatic reduction rate(%)/bacteriostatic activity value A comparison sample and a test sample are prepared according to KS K 0693-2001, then bacteria is cultivated on the respective sample for 18 hours, and then the viable count (Ma) of the comparison sample after 18 hours of cultivation and the viable count (Mb) of the test sample after 18 hours of cultivation are obtained. These values are substituted into the following expression to calculate the bateriostatic reduction rate(%) and the bacteriostatic activity value. Bacteriostatic reduction rate(%) = Bacteriostatic activity value = log Ma - log Mb ■ absorption property [I) absorption rate (mm/10 mm) The absorption rate is measured by Birack method (wicking test) which is the KS K 0815.5.27 method. A test sample is prepared by knitting a circular knit fabric by a 32-gauge interlock double circular knitting machine using the multifilament of the present invention and then cutting the same to a width of 2.5cm and a length of 20cm. One portion of the fabric sample is dipped in water to a depth of 2.5cm for ten minutes, and then the height of moisture absorbed into the woven fabric sample is measured three times to thus obtain the average value. (II) absorption area(cm2/30 min) The absorption area is measured by a drop application method. The circular knit fabric (20cm wide by 20cm long) made from the multifilament of the present invention is positioned and fixed around a cylindrical tube having a diameter of 7.5cm and then fixed, 0.05ml of water is dropped thereon, and after 30 seconds, the maximum width (a) and the minimum width (B) of the water diffused portion of the test sample are measured. Next, the measured values (a and b) are substituted into the following expression to calculated the absorption area. Absorption area = • fast drying property : drying time (min) A test sample is made by knitting a circular knit fabric by a 32-gauge interlock double circular knitting machine using the multifilament of the present invention and then cutting the same to a width of 20cm and a length of 20cm. The drying rate is obtained by dropping 0.05ml of water on the fabric sample and measuring the time required for the fabric sample to reach dryness. At this time, environmental conditions were 20°C and 65% RH. ADVANTAGEOUS EFECTS The multifilament of the present invention is excellent in sweat absorption and fast drying properties and also excellent in antibacterial properties, and continuously exhibits good antibacterial properties even after repeated washings. Consequently, the multifilament is not discolored or decolorized by bacteria, is sanitary because it does not give off a bad smell, and exhibits excellent comfort when worn. 2') BRIEF DESCRIPTION OF THE DRAWINGS Other objects and aspects of the present invention will become apparent from the following description of embodiments with reference 12 to the accompanying drawing in which: Fig. 1 is a schematic process chart for producing multifilament excellent in antibacterial properties and sweat absorption and fast drying properties according to the present invention; Fig. 2 is a pattern diagram of a cross section of monofilaments comprising the multifilament of the present invention; Fig. 3 is an expanded view of a cross section of a spinneret used in the present invention; Figs. 4 and 5 are pattern diagrams of a cross section of a conventional modified cross section fiber; and Fig. 6 is a pattern diagram of a moisture-diffused portion of a test sample when the absorption area is measured by a drop application method. Explanation of reference numerals in the drawings. 1: polymer chip feed pipe 2: side feeder 3: extruder 4: spinneret 5: cooling chamber 6: focusing guide 7: first godet roll 8: second godet roll 9: take-up machine L1: long axis length of cross section of monofilament L2: short axis length of cross section of monofilament L3: interval between central protuberances in major axial direction of cross section of monofilament 13 D1: short axis width of cross section of monofilament a: maximum width of moisture-diffused portion of test sample b: minimum width of moisture-diffused portion of test sample BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be explained in further detail with reference to the examples and comparative examples, with the understanding that the invention is not limited merely to these examples. Example 1 A spinning solution was prepared by supplying a polyester chip to an extruder 3 through a feed pipe 1 and a polyester chip (master batch chip) to the extruder 3 through a side feeder 2, the polyester chip containing a silver-based inorganic antibacterial agent (NOVARON®) with silver substituted in zirconium phosphate, an inorganic carrier, and then mixed-melting them. At this time, the content of the silver-based inorganic antibacterial agent in the spinning solution was 0.5% by weight. Continuously, the prepared spinning solution was spun at a spinning temperature of 289°C by a spinneret of Fig. 3 (discharge rate: 35.1g/min), was solidified by a cooling wind with a wind velocity of 0.5m/sec, and was passed through a first Godet roller of 82°C (rotational linear velocity: l,500m/min) and a second Godet roller of 125°C (rotational linear velocity: 4,300 m/min) in turns, and then wound at a speed of 4,200m/min, thereby manufacturing multifilament of 75 deniers/24 filaments having a [L1/L2] ratio of 2.5 and a [L2/D1] ratio of 1.5. By using the manufactured multifilament, a circular knit fabric with a diameter of 26 inches was manufactured by a 32-gauge interlock double circular knitting machine. The result of measuring various physical properties and workability of the manufactured filament and circular knit fabric is as shown in Table 2. Example 2 and Comparative Examples 1 to 3 Except that a cross section shape of monofilaments and the type and content of an antibacterial agent were changed as shown in Table 1, multifilament and its circular knit fabric were manufactured. The result of measuring various physical properties and workability of the manufactured filament and circular knit fabric is as shown in Table 2. 15 Table 1 Manufacturing Conditions Classification Cross section shape of monofilament Antibacterial agent Type (product name) Content in spun dope (% by weight) Example 1 Fig. 2 Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.5 Example 2 Fig. 2 Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.7 Comparative Example 1 circular Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.4 Comparative Example 2 circular Silver-zeolite based antibacterial agent 0.7 Comparative Example 3 circular Glass based anatibacterial agent 0.7 Table 2 Result of workability and physical properties Classification Workability (F/D rate, %) Antibacterial properties Absorption rate (cm/min) Drying rate (min) Bacteriosta tic reduction rate(%) Bacteriostatic activity value Absorption rate(mm/ 1 Omin) Absorption area(cm2/ 30min) Example 1 98.0 99.9 5.6 135 10.6 28 Example 2 96.0 99.9 6.3 145 13.2 32 Comparative Example 1 98.0 98.0 2.0 67 5.2 52 Comparative Example 2 78.3 99.1 2.2 58 4.4 54 Comparative Example 3 62.3 99.0 2.0 62 4.8 62 INDUSTRIAL APPLICABILITY The multifilament of the present invention is excellent in sweat absorption and fast drying properties and also excellent in antibacterial properties, and continuously exhibits good antibacterial properties even after repeated washings. Consequently, the fiber is not discolored or decolorized by bacteria, is sanitary because it does not give off a bad smell, and exhibits excellent wearing comfort. Resultantly, the multifilament of the present invention is useful as yarn for apparel such as sports clothes. WE CLAIM : 1. A multifilament, characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a non-circular cross section in which six spherical protuberances, that is, two on the top surface and two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (Li) of the cross section of the monofilaments, and (III) the multifilament contains 0.3 to 2.0% by weight of a silver-based inorganic antibacterial agent with silver(Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to l.0µm 2. The multifilament of claim 1, wherein the short axis length (L2) of the cross section of the monofilament is 1.0 to 4.0 times larger than the short axis width (D1) of the cross section of the monofilament and the long axis length (L1) of the cross section of the monofilament is 1.0 to 4.0 times larger than the short axis length (L2) of the cross section of the monofilament. 3. The multifilament of claim 1, wherein the thermoplastic resin is polyester resin. 4. The multifilament of claim 1, wherein the bacteriostatic reduction rate and bacteriostatic activity value measured by KS K 0693-2001 method are 99.00 to 99.99% and 2.2 to 6.3, respectively. 5. The multifilament of claim 1, wherein the absorption rate measured by Birack method (Wicking Test) is 100 to 185mm/10 min. 6. The multifilament of claim 1, wherein the absorption area measured by a drop application method is 8 to 14cm2/30sec. 7. The multifilament of claim 1, wherein the drying time required for complete removal of 0.05ml of moisture in the yarn is 20 to 40 minutes. Dated this 14th day of May, 2005 (SAIMA SAGHIR ANSARI) KRISHNA &SAURASTRI" FOR KOLON INDUSTRIES, INC. By their Agent.

Full Text

FORM 2
THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
A MULTI-FILAMENT WITH EXCELLENT ABSORPTION-DRY PROPERTY AND ANTIBIOTIC PROPERTY;
KOLON INDUSTRIES, INC. A
CORPORATION ORGANIZED AND EXISTING
UNDER THE LAWS OF KOREA, WHOSE
ADDRESS IS KOLON TOWER, 1-23,
BYULYANG-DONG, KWACHEON-SI,
KYUNGGI-DO 427-040, REPU BLIC OF KOREA.
THE FOLLOWING SPECIFICATION
PARTICULARLY DESCRIBES THE

INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD
The present invention relates to yarn for apparel, and more particularly, to a multifilament which exhibit excellent sweat absorption properties as well as rapid drying of absorbed sweat (hereinafter, sweat absorption and fast drying properties') when used as yarn for sports apparel and which exhibit excellent suppression of the saturation and growth of bacteria that cause the discoloration and decolorization of fiber and are detrimental to human health (hereinafter, 'antibacterial properties').
BACKGROUND ART
Recently, with the rise in the standard of living, the demand for
clothes with various functions is increasing. In other words, there is a
need for clothes with sweat absorption and fast drying properties as
well as physical and chemical durability. Conventionally, cotton yarns
or mixed yarns of cotton and polyester with good absorption have been
commonly used as yarns for clothes. However, when subjected to
heavy perspiration, the above-mentioned yarns absorb a great deal of sweat, and therefore they afford a wet and cold feeling and the clothes made from the yarn cling and stick to the body of the wearer. Moreover,

fibers may be discolored or decolorized by bacteria or may produce foul odors, like sweat, when worn for a long time, in other words, antibiotic properties are insufficient.
Meanwhile, U.S. Patent Application No. 4,470,407 discloses a polyester non-circular cross section fiber having a scalloped-oval cross section as shown in Fig. 4 in order to enhance the moisture diffusion of the fiber, and Korean Patent Laid-Open No. 1999-7736 discloses a non-circular cross section fiber with 3 to 5 spherical projections formed at equal intervals. The above-mentioned conventional non-circular cross section fibers have only 2 to 5 protuberances serving as a passage for dispersing sweat, and therefore they are inferior in sweat absorption and fast drying properties and comfort. Also they have no antibacterial properties.
Meanwhile, Korean Patent Laid-Open No. 2002-71522 discloses a non-circular cross section fiber with six spherical protuberances formed symmetrically as shown in Fig. 2. The above-mentioned non-circular cross section fiber is excellent in sweat absorption and fast drying properties but is lacking in antibacterial properties.
As a conventional technique for providing fiber with antibacterial properties, a method of providing antibacterial properties by immersing fabrics in an antibacterial agent solution has been used widely. In this case, however, the antibacterial function is lost after more than 10 washings, i.e., the washing resistance is low.
3

As another conventional technique for providing fiber with antibacterial properties, there have been used a method of copolymerizing a copolymer component comprising an antibacterially active substance in polymer resin that is a fiber material and a method of blending the polymer resin with a fine antibacterial agent and so on.
As the antibacterial agent, a natural antibacterial agent such as chitosan or a silver based inorganic antibacterial agent or an antibacterial agent having a photocatalytic function is used, but an inorganic antibacterial agent which is highly resistant to high temperature spinning is more widely used.
Although the aforementioned methods can provide antibacterial properties, they are inferior in washing resistance and cannot provide both sweat absorption and fast drying properties simultaneously.
It is, therefore, an object of the present invention to overcome the above problems, and provide yarn (multifilament) which is excellent in both sweat absorption and fast drying properties and antibacterial properties.
DISCLOSURE OF THE INVENTION TECHNOLOGICAL PROBLEM
The present invention provides improved sweat absorption and rapid drying by forming the cross sections of monofilaments comprising yarn (multifilament) in a modified form in which six spherical
4

protuberances are symmetrically formed as shown in Fig. 2, and provides a multifilament with antibacterial properties without deteriorating workability by dispersing and containing a silver-based inorganic antibacterial agent (diameter: 0.1 to l.Ojum) with silver(Ag) substituted in zirconium phosphate. TECHNOLOGICAL SOLUTION
To achieve the above objects, there is provided a multifilament according to the present invention, characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a non-circular cross section in which six spherical protuberances, that is, two on the top surface and two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (Li) of the cross section of the monofilaments, and (III) the multifilament contains 0.3 to 2.0% by weight of a silver-based inorganic antibacterial agent with silver(Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to 1.0im\.
A preferred embodiment of the present invention will now be described with reference to the accompanying drawings.
Firstly, the present invention relates to a multi-filament consisting of thermoplastic monofilaments. The cross section of the monofilament has six spherical protuberances of different sizes
5

symmetrically formed as shown in Fig 2. More specifically, the monofilaments have a cross section in which six spherical protuberances, i.e., two on the top surface, two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length(L1) of the cross section of the monofilaments. On the cross section of the monofilament, the ratio of the short axis length (L2) of the monofilament to the short axis width (Di) thereof [L2/D1] is 1.0 to 4.0. If the ratio of L2/D1 is less than 1.0, the sweat absorption and fast drying properties are degraded, if it exceeds 4.0, the sweat absorption and fast drying properties and the workability are degraded.
In addition, it is preferred that the ratio of long axis length (L1) of monofilament to the short axis length (L2) of monofilament (L1/L2) is 1.0 to 4.0. Beyond this range, the workability and the sweat absorption and fast drying properties may be degraded.
In the present invention, as thermoplastic resin, polyamide, polyester, polyacryl or the like can be used. More preferably, hydrophobic polyester is used as the thermoplastic resin.
The multifilament (yarn) of the present invention has excellent sweat absorption properties because six protuberances of different sizes serve as a passage for rapidly discharging sweat from the body of a wearer to the surface of clothes. In addition, the non-multifilament (yarn) of the present invention exhibits a property of rapid evaporation
6

of sweat discharged to the surface of clothes in the air (rapid sweat drying property) because it has a very large surface area in contact with the air.
Moreover, the multifilament (yarn) of the present invention prevents the phenomenon that clothes cling to the body even if a wearer perspires profusely because it has a small contact area with the body, thereby affording excellent comfot when worn. The multifilament (yarn) of the present invention can be mainly used in producing clothes such as jackets by using it alone or mixing it with cotton or polypropylene yarn.
The multifilament (yarn) of the present invention contains 0.3 to 2.0% by weight, with respect to the total yarn weight, of a silver-based inorganic antibacterial agent having an average particle diameter of 0.1
to l.OjOTl.
The aforementioned silver-based inorganic antibacterial agent is an antibacterial agent with silver substituted in zirconium phosphate (ZrO2P2O5), an inorganic carrier, that is to say, 'NOVARON®" manufactured by Toagosei Co. Ltd, Japan.
The above silver-based inorganic antibacterial agent inhibits metabolic functions necessary for life support since silver ions act on bacteria, and destroys cell membranes of bacteria by generating active oxygen (O2) under the existence of water and light.
If the average particle diameter of the silver-based inorganic
7

antibacterial agent exceeds l.0µm, it becomes difficult to produce fine yarn less than 2 deniers and the pressure of a spinning pack is sharply increased, thus deteriorating the workability (Full-Drum rate). If the average particle diameter is less than 0.1/µm, the dispersability of the antibacterial agent is poor, thus deteriorating the workability and increasing costs.
If the content of the silver-based inorganic antibacterial agent in the yarn exceeds 2.0% by weight, the production costs become higher and the dispersability is lowered, thus deterioarting the workability. If less than 0.3% by weight, a sufficient antibacterial function cannot be obtained.
The multifilament of the present invention can be produced through the process shown in Fig. 1.
Fig. 1 is a schematic process chart illustrating the production of multifilament according to the present invention.
Specifically, a thermoplastic polymer chip is supplied to an extruder 3 through a thermoplastic polymer chip feed pipe 1, and at the same time a thermoplastic polymer chip (hereinafter, 'master batch chip') to which a silver-based inorganic antibacterial agent has been added is supplied to the extruder 3 through a side feeder 2. Continuously, the thermoplastic polymer chip and the thermoplastic polymer chip (master batch chip) to which the silver-based inorganic antibacterial agent has been melted and mixed together in extruder 3.
8

Continuously, the melted polymer is melt-spun through a spinneret 4 having a cross section as shown in Fig. 3, cooled by a cooling chamber 5, drawn between a first godet roll 7 and a second godet roll 8 through a focusing guide 6, and is then wound by a take-up machine 9, thereby producing the multifilament of the present invention.
Preferably, the temperature of the first godet roll 7 is about 85°C, and the rotational linear velocity thereof is about l,500m/min.
Preferably, the temperature of the second godet roll 8 is about 123°C, and the rotational linear velocity thereof is about 4,300m/min.
Preferably, the winding velocity of the take-up machine 9 is about 4,200m/min.
In the present invention, however, the rotational linear velocity and temperature of the first godet roll 7, second godet roll 8 and take-up machine 9 are not specifically limited.
At this time, it is more preferable to produce a master batch chip and then supply the master batch chip to the extruder 3 through the feeder 2 as shown above in terms of dispersability and workability, rather than to directly put the silver-based inorganic antibacterial agent into the extruder 3.
The present invention has a full drum rate of more than 95% owing to excellence workability.
The multifilament of the present invention has a bacteriostatic

reduction rate of 99.00 to 99.99% and a bacteriostatic activity value of 2.2 to 6.3 as measured according to the KS K 0693-2001 method.
Moreover, the multifilament of the present invention has an absorption rate of 100 to 185mm/10 min as measured by the Birack method (Wicking Test), and an absorption area of 8 to 14cm2/30sec as measured by a drop application method.
Moreover, the multifilament of the present invention exhibits a drying time of 20 to 40 minutes for which the moisture of 0.05mC in the yarn is dried out.
In the present invention, a variety of physical properties of the multifilament are evaluated as follows. ■ workability(F/D rate)
The ratio of full drums to the total number of drums produced in a spinning process is obtained.
• bacteriostatic reduction rate(%)/bacteriostatic activity value
A comparison sample and a test sample are prepared according to KS K 0693-2001, then bacteria is cultivated on the respective sample for 18 hours, and then the viable count (Ma) of the comparison sample after 18 hours of cultivation and the viable count (Mb) of the test sample after 18 hours of cultivation are obtained. These values are substituted into the following expression to calculate the bateriostatic reduction rate(%) and the bacteriostatic activity value.

Bacteriostatic reduction rate(%) =

Bacteriostatic activity value = log Ma - log Mb ■ absorption property
[I) absorption rate (mm/10 mm)
The absorption rate is measured by Birack method (wicking test) which is the KS K 0815.5.27 method. A test sample is prepared by knitting a circular knit fabric by a 32-gauge interlock double circular knitting machine using the multifilament of the present invention and then cutting the same to a width of 2.5cm and a length of 20cm. One portion of the fabric sample is dipped in water to a depth of 2.5cm for ten minutes, and then the height of moisture absorbed into the woven fabric sample is measured three times to thus obtain the average value.
(II) absorption area(cm2/30 min)
The absorption area is measured by a drop application method.
The circular knit fabric (20cm wide by 20cm long) made from the multifilament of the present invention is positioned and fixed around a cylindrical tube having a diameter of 7.5cm and then fixed, 0.05ml of water is dropped thereon, and after 30 seconds, the maximum width (a) and the minimum width (B) of the water diffused portion of the test sample are measured. Next, the measured values (a and b) are substituted into the following expression to calculated the absorption area.

Absorption area =
• fast drying property : drying time (min)
A test sample is made by knitting a circular knit fabric by a 32-gauge interlock double circular knitting machine using the multifilament of the present invention and then cutting the same to a width of 20cm and a length of 20cm. The drying rate is obtained by dropping 0.05ml of water on the fabric sample and measuring the time required for the fabric sample to reach dryness. At this time, environmental conditions were 20°C and 65% RH.
ADVANTAGEOUS EFECTS
The multifilament of the present invention is excellent in sweat absorption and fast drying properties and also excellent in antibacterial properties, and continuously exhibits good antibacterial properties even after repeated washings.
Consequently, the multifilament is not discolored or decolorized by bacteria, is sanitary because it does not give off a bad smell, and exhibits excellent comfort when worn.
2') BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and aspects of the present invention will become apparent from the following description of embodiments with reference
12

to the accompanying drawing in which:
Fig. 1 is a schematic process chart for producing multifilament excellent in antibacterial properties and sweat absorption and fast drying properties according to the present invention;
Fig. 2 is a pattern diagram of a cross section of monofilaments comprising the multifilament of the present invention;
Fig. 3 is an expanded view of a cross section of a spinneret used in the present invention;
Figs. 4 and 5 are pattern diagrams of a cross section of a conventional modified cross section fiber; and
Fig. 6 is a pattern diagram of a moisture-diffused portion of a test sample when the absorption area is measured by a drop application method.
Explanation of reference numerals in the drawings.
1: polymer chip feed pipe 2: side feeder
3: extruder 4: spinneret
5: cooling chamber 6: focusing guide
7: first godet roll 8: second godet roll
9: take-up machine
L1: long axis length of cross section of monofilament L2: short axis length of cross section of monofilament L3: interval between central protuberances in major axial direction of cross section of monofilament
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D1: short axis width of cross section of monofilament
a: maximum width of moisture-diffused portion of test sample
b: minimum width of moisture-diffused portion of test sample
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention will now be explained in further detail with reference to the examples and comparative examples, with the understanding that the invention is not limited merely to these examples.
Example 1
A spinning solution was prepared by supplying a polyester chip to an extruder 3 through a feed pipe 1 and a polyester chip (master batch chip) to the extruder 3 through a side feeder 2, the polyester chip containing a silver-based inorganic antibacterial agent (NOVARON®) with silver substituted in zirconium phosphate, an inorganic carrier, and then mixed-melting them.
At this time, the content of the silver-based inorganic antibacterial agent in the spinning solution was 0.5% by weight.
Continuously, the prepared spinning solution was spun at a spinning temperature of 289°C by a spinneret of Fig. 3 (discharge rate: 35.1g/min), was solidified by a cooling wind with a wind velocity of 0.5m/sec, and was passed through a first Godet roller of 82°C (rotational linear velocity: l,500m/min) and a second Godet roller of

125°C (rotational linear velocity: 4,300 m/min) in turns, and then wound at a speed of 4,200m/min, thereby manufacturing multifilament of 75 deniers/24 filaments having a [L1/L2] ratio of 2.5 and a [L2/D1] ratio of 1.5.
By using the manufactured multifilament, a circular knit fabric with a diameter of 26 inches was manufactured by a 32-gauge interlock double circular knitting machine. The result of measuring various physical properties and workability of the manufactured filament and circular knit fabric is as shown in Table 2.
Example 2 and Comparative Examples 1 to 3
Except that a cross section shape of monofilaments and the type and content of an antibacterial agent were changed as shown in Table 1, multifilament and its circular knit fabric were manufactured.
The result of measuring various physical properties and workability of the manufactured filament and circular knit fabric is as shown in Table 2.
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Table 1
Manufacturing Conditions

Classification Cross section
shape of monofilament Antibacterial agent

Type (product name) Content in spun
dope
(% by weight)
Example 1 Fig. 2 Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.5
Example 2 Fig. 2 Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.7
Comparative Example 1 circular Silver-based inorganic antibacterial agent with silver substituted in zirconium phosphate (NOVARON®) 0.4
Comparative Example 2 circular Silver-zeolite based antibacterial agent 0.7
Comparative Example 3 circular Glass based anatibacterial agent 0.7

Table 2
Result of workability and physical properties

Classification Workability
(F/D
rate, %) Antibacterial properties Absorption rate (cm/min) Drying rate (min)

Bacteriosta
tic
reduction
rate(%) Bacteriostatic activity value Absorption
rate(mm/ 1
Omin) Absorption
area(cm2/
30min)

Example 1 98.0 99.9 5.6 135 10.6 28
Example 2 96.0 99.9 6.3 145 13.2 32
Comparative Example 1 98.0 98.0 2.0 67 5.2 52
Comparative Example 2 78.3 99.1 2.2 58 4.4 54
Comparative Example 3 62.3 99.0 2.0 62 4.8 62

INDUSTRIAL APPLICABILITY
The multifilament of the present invention is excellent in sweat absorption and fast drying properties and also excellent in antibacterial properties, and continuously exhibits good antibacterial properties even after repeated washings.
Consequently, the fiber is not discolored or decolorized by bacteria, is sanitary because it does not give off a bad smell, and exhibits excellent wearing comfort.
Resultantly, the multifilament of the present invention is useful as yarn for apparel such as sports clothes.

WE CLAIM :
1. A multifilament, characterized in that: (I) the multifilament consists of thermoplastic monofilaments, (II) the monofilaments have a non-circular cross section in which six spherical protuberances, that is, two on the top surface and two on the bottom surface, one on the left surface and one on the right surface are formed symmetrically with respect to the long axis length (Li) of the cross section of the monofilaments, and (III) the multifilament contains 0.3 to 2.0% by weight of a silver-based inorganic antibacterial agent with silver(Ag) substituted in zirconium phosphate, an inorganic carrier, with respect to the total yarn weight having an average particle diameter of 0.1 to l.0µm
2. The multifilament of claim 1, wherein the short axis length (L2) of the cross section of the monofilament is 1.0 to 4.0 times larger than the short axis width (D1) of the cross section of the monofilament and the long axis length (L1) of the cross section of the monofilament is 1.0 to 4.0 times larger than the short axis length (L2) of the cross section of the monofilament.
3. The multifilament of claim 1, wherein the thermoplastic resin is polyester resin.

4. The multifilament of claim 1, wherein the bacteriostatic reduction
rate and bacteriostatic activity value measured by KS K 0693-2001
method are 99.00 to 99.99% and 2.2 to 6.3, respectively.
5. The multifilament of claim 1, wherein the absorption rate measured by Birack method (Wicking Test) is 100 to 185mm/10 min.
6. The multifilament of claim 1, wherein the absorption area measured by a drop application method is 8 to 14cm2/30sec.
7. The multifilament of claim 1, wherein the drying time required for
complete removal of 0.05ml of moisture in the yarn is 20 to 40 minutes.
Dated this 14th day of May, 2005

(SAIMA SAGHIR ANSARI) KRISHNA &SAURASTRI"
FOR KOLON INDUSTRIES, INC. By their Agent.

A MULTI-FILAMENT WITH EXCELLENT ABSORPTION-DRY PROPERTY AND ANTIBIOTIC PROPERTY

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