KR20240081803A - Polyethylene yarn with improved weaving properties and functional fabric containing the same - Google Patents

Abstract

The present invention relates to a polyethylene yarn with improved weaving properties and a functional fabric containing the same. More specifically, the present invention relates to a polyethylene yarn with improved weaving properties and a functional fabric containing the same. More specifically, the present invention relates to a weaving property that can provide the user with an appropriate cooling sensation and an excellent wearing feeling and is capable of producing a fabric with a very low frequency of hair generation. It relates to improved polyethylene yarn and functional fabric containing it.
The polyethylene yarn according to the present invention has a polydispersity index (PDI) of 5 or more and 20 or less, a strength measured according to ASTM D885 of 1.5 to 10 g/d, and an elongation at maximum strength of 10 to 50%.

Description

Polyethylene yarn with improved weaving properties and functional fabric containing the same {Polyethylene yarn with improved weaving properties and functional fabric containing the same}

The present invention relates, more specifically, to polyethylene yarn with improved weaving properties and functional fabric containing the same. The present invention relates to a polyethylene yarn with improved weaving properties that can provide an appropriate cool feeling and excellent fit to the user and can produce a fabric with a very low incidence of wool, functional fabrics containing the same, and cool-sensitive products.

Recently, due to improvements in living standards and population growth, the demand for fibers is changing from general-purpose yarns for general clothing and industrial fibers to high-performance, high-performance, high-tech fiber materials with various functions. In particular, the development of textile materials with cooling properties that provide users with a sense of comfort in summer or high-temperature working environments is being actively conducted.

Cold-sensitive textile materials are given cold sensitivity by using the thermal conductivity of the fiber itself, or by adjusting the thermal conductivity of the surface of the fiber material through coating of a metal component with high thermal conductivity. In particular, cool-sensitive textile materials using the thermal conductivity of the fiber itself can be manufactured only through the weaving process of the fabric, and can maintain cool sensitivity even after washing, so they are currently produced in a variety of industrial fields.

Conventionally, cold-sensitive textile materials using the thermal conductivity of the fiber itself include the excellent thermal conductivity of high molecular weight polyethylene (HMWPE) fibers, as disclosed in Japanese Patent Publication JP 2010-236130A and Korean Patent Publication No. 10-2017-0135342. Attempts are being made to apply it to various fields of fashion clothing and technical textiles that require high coolness, such as sportswear, mountaineering clothing, and workwear.

However, conventional high molecular weight polyethylene fibers have high strength as they are manufactured into yarn by maximizing crystallinity and orientation to develop cold sensitivity. Accordingly, there is a disadvantage that the elongation of the yarn is low, so weaving properties are poor, and the fabric produced has a relatively poor wearing comfort due to low flexibility.

The purpose of the present invention is to provide a polyethylene yarn with improved weaving properties, which can provide an appropriate cool feeling and excellent fit to the user, and which can produce a fabric with a very low frequency of hair generation, a functional fabric containing the same, and a cold-sensitive product. .

The polyethylene yarn according to the present invention has a polydispersity index (PDI) of 5 or more and 20 or less, a strength measured according to ASTM D2256 of 1.5 to 10 g/d, and an elongation at maximum strength of 10 to 50%.

In the polyethylene yarn according to an embodiment of the present invention, the polyethylene yarn is subjected to gel filtration chromatography (GPC) analysis with the log scale of molecular weight (Mw) as the x-axis and the weight distribution (dw/dLogM) as the y-axis. The following equation 1 is satisfied in the weight distribution graph, and the weight distribution graph may be unimodal.

[Equation 1]

(Mw _max - Mw _aver )< (Mw _aver - Mw _min )

(In the above formula, Mw _aver is the molecular weight with the maximum weight distribution in the weight distribution graph, and Mw _max and Mw _min mean the two molecular weights corresponding to 0.25Q in the weight distribution graph with respect to the weight distribution value Q in Mw _aver . (Mw _maw refers to the maximum value of the two molecular weights, and Mw _min refers to the minimum value.)

In the polyethylene yarn according to an embodiment of the present invention, the yarn may have an initial modulus of 30 to 80 d/g, as measured according to ASTM 2256.

In the polyethylene yarn according to an embodiment of the present invention, the yarn may have a crystallinity of 65 to 85%.

In the polyethylene yarn according to an embodiment of the present invention, the yarn may have a density of 0.93 to 0.97 g/cm ³ .

In the polyethylene yarn according to an embodiment of the present invention, the yarn may have a weight average molecular weight of 90,000 to 400,000 g/mol.

The polyethylene fabric according to the present invention includes the polyethylene yarn described above.

In the polyethylene fabric according to an embodiment of the present invention, the fabric is heated at 20±2℃, 65±2% R.H. by contacting a heating plate (T-box) at 30±2℃ with respect to the fabric at 20±2℃. The measured contact cooling may be 0.18 to 0.30 W/cm2.

In the polyethylene fabric according to an embodiment of the present invention, the fabric is contacted with a heat source plate (BT-box) at 30±2°C for the fabric at 20±2°C at 20±2°C and 65±2% R.H. The thermal conductivity in the thickness direction measured may be 0.05 to 0.20 W/mK.

In the polyethylene fabric according to an embodiment of the present invention, the number of hairs generated in the fabric may be 10 or less per 100,000 m2.

In the polyethylene fabric according to an embodiment of the present invention, the fabric may have an area density of 150 to 800 g/m2.

The cool-sensitive product according to the present invention is manufactured from the above-described fabric.

The polyethylene yarn according to the present invention has excellent thermal conductivity and improved weaving properties, making it possible to manufacture a fabric with appropriate cooling characteristics and a very low incidence of fuzz.

In addition, since the functional fabric according to the present invention contains polyethylene yarns with excellent thermal conductivity and high weaving properties, it can have excellent quality with cooling characteristics and fewer defects such as fuzz.

In addition, the functional fabric according to the present invention not only has a cooling effect but also has excellent drape properties, so when a user wears a product made from such a fabric, the contact area between the user and the product is high, so that a substantially better cooling effect can be achieved. there is.

Figure 1 is a schematic diagram schematically showing a polyethylene yarn manufacturing apparatus according to an embodiment of the present invention.
Figure 2 is a schematic diagram schematically showing a device for measuring the contact cooling sensation of a fabric.
Figure 3 is a schematic diagram schematically showing a device for measuring thermal conductivity in the thickness direction of a fabric.
Figure 4 is a weight distribution graph through GPC analysis of the yarn according to Example 3.

Unless otherwise defined, the technical and scientific terms used in this specification have the meanings commonly understood by those skilled in the art to which this invention pertains, and the gist of the present invention is summarized in the following description and accompanying drawings. Descriptions of known functions and configurations that may unnecessarily obscure are omitted.

Additionally, as used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise.

In addition, units used without special mention in this specification are based on weight, and as an example, the unit of % or ratio means weight % or weight ratio, and weight % refers to the amount of any one component of the entire composition unless otherwise defined. It refers to the weight percent occupied in the composition.

In addition, the numerical range used in this specification includes the lower limit and upper limit and all values within the range, increments logically derived from the shape and width of the defined range, all double-defined values, and the upper limit of the numerical range defined in different forms. and all possible combinations of the lower bounds. Unless otherwise specified in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

The term 'comprise' in this specification is an open description with the same meaning as expressions such as 'comprising', 'contains', 'has' or 'characterized by', and includes elements that are not additionally listed, Does not exclude materials or processes.

Conventional high molecular weight polyethylene fibers are manufactured into yarn by maximizing the degree of crystallinity and orientation to develop cold sensitivity, so there is a disadvantage in that the strength of the yarn is high and the elongation is low, resulting in poor weaving properties. In addition, the tensile strength of the manufactured yarn is poor, which not only further reduces weaving properties, but also makes the fabric manufactured from it have poor drapability and wearability. Accordingly, when the user actually wears it, there is a disadvantage in that the actual cooling effect felt by the user is not excellent because the contact area between the user and the fabric is not high.

Accordingly, the present applicant conducted long-term, in-depth research to develop polyethylene fibers that maintain cooling properties but have excellent weaving properties. As a result, polyethylene fibers with a specific polydispersity index, strength, and elongation have appropriate thermal conductivity but have excellent weaving properties. It was discovered that it could be manufactured as a fabric with superior physical properties, and as a result of in-depth research on this, the present invention was completed.

In this specification, polyethylene yarn refers to mono and multifilaments manufactured through processes such as spinning and stretching using polyethylene chips as raw materials. As an example, polyethylene fibers may include 40 to 500 filaments each having a fineness of 1 to 3 denier, and may have a total fineness of 100 to 1,000 denier.

The polyethylene yarn of the present invention has a polydispersity index (PDI) of 5 or more and 20 or less, a strength measured according to ASTM D2256 of 1.5 to 10 g/d, and an elongation at maximum strength of 10 to 50%, and has excellent thermal conductivity. At the same time, the weaving properties are improved, so it can be manufactured into a fabric with appropriate cooling characteristics but with a very low frequency of hair generation.

The cold sensitivity of the fabric containing the polyethylene yarn according to the present invention is a characteristic that allows the user wearing the fabric to feel an appropriate cold sensation, that is, a cooling feeling, through the high thermal conductivity of the yarn. Specifically, in the case of polymers, heat is mainly transferred within the polymer (particularly in the direction of molecular chains connected through covalent bonds) through lattice vibrations called phonons. In other words, the thermal conductivity of the yarn, even if the yarn is manufactured from the same resin, can be adjusted differently depending on the structural characteristics of the polymer itself, such as the degree of crystallinity and orientation of the yarn.

As described above, yarns with a polydispersity index (PDI) of 5 or more and 20 or less, a strength measured according to ASTM D2256 of 1.5 to 10 g/d, and an elongation at maximum strength of 10 to 50% have excellent thermal conductivity. However, it has high flexibility and can have excellent weaving properties, so it can be manufactured into a fabric with high cooling characteristics but low incidence of wool.

Specifically, the polydispersity index may be 7 or more and 20 or less, or 11 to 16, more specifically, 12 to 15. At this time, the strength measured according to ASTM D2256 may be 5 to 10 g/d, or 6 to 9 g/d, specifically, 7 to 8 g/d, and the elongation at maximum strength may be 10 to 30%, or 15 to 25%. %, more specifically, it may be 17 to 23%, but is not limited thereto. However, within the above range, it can have high thermal conductivity and at the same time an appropriate stiffness that is advantageous for weaving properties.

In particular, polyethylene yarn is measured in a weight distribution graph through gel permeation chromatography (GPC) analysis, with the log scale of molecular weight (Mw) as the x-axis and the weight distribution (dw/dlogM) as the y-axis. When the following equation 1 is satisfied, the fabric can be manufactured with superior thermal conductivity and a very low frequency of hair generation. At this time, the weight distribution graph is unimodal.

[Equation 1]

(Mw _max - Mw _aver ) < (Mw _aver - Mw _min )

(In the above formula, Mw _aver is the molecular weight with the maximum weight distribution in the weight distribution graph, and Mw _max and Mw _min mean the two molecular weights corresponding to 0.25Q in the weight distribution graph with respect to the weight distribution value Q in Mw _aver . (Mw _maw refers to the maximum value of the two molecular weights, and Mw _min refers to the minimum value.)

Polyethylene yarn that satisfies Equation 1 above has a wide weight distribution at a relatively low molecular weight. Such polyethylene yarn has excellent thermal conductivity due to phonons and can have high flexibility and strength, so it has better weaving properties, and thus can be manufactured into a cold-sensitive fabric with a very low frequency of hair generation.

Additionally, as Equation 1 is satisfied, the value of (Mw _max - Mw _aver ) - (Mw _aver - Mw _min ) may be a negative number. As an example, it may be more than 0 and less than -3, specifically more than 0 and less than -1, and more specifically more than 0 and less than -0.5, but of course, it is not limited thereto.

Gel permeation chromatography analysis was performed using the following analysis equipment after completely dissolving the polyethylene yarn in the solvent below.

- Analysis device: Tosoh HLC-8321 GPC/HT

- Column: PLgel guard (7.5 x 50 mm) + 2 x PLgel mixed-B (7.5 x 300 mm)

- Column temperature: 160 ℃

- Solvent: Trichlorobenzene (TCB) + 0.04 wt.% dibutylhydroxytoluene (BHT) (after drying with 0.1% CaCl ₂ )

- Injector, detector temperature: 160 ℃

- Detector: RI Detector

- Flow rate: 1.0 ㎖/min

- Injection volume: 300 mL

- Sample concentration: 1.5 mg/mL

- Standard sample: polystyrene

In addition, polyethylene yarn may have a lower initial modulus than conventional polyethylene yarn for cooling, that is, the initial modulus measured according to ASTM D2256 may be 50 to 100 g/d, specifically, 30 to 80 g/d. If the initial modulus of the polyethylene yarn is higher than the above range, the elasticity is good, but the stiffness may deteriorate. If the initial modulus of the polyethylene yarn is lower than the above range, the stiffness is good, but the elastic recovery power is lowered, which may deteriorate the toughness of the fabric. In other words, as it has appropriate stiffness and toughness within the above range, it can have better weaving properties, and thus can be manufactured into a fabric with excellent drape properties.

In one aspect, the polyethylene yarn may have a weight average molecular weight of 20,000 to 200,000 g/mol, preferably 30,000 to 150,000 g/mol. Within the above range, when melt extruding yarn, the flowability of the melt is good, thermal decomposition is prevented, and processability is ensured such that thread breakage does not occur during stretching, so yarn with uniform physical properties can be manufactured and fabric with excellent durability is provided. can do

In addition, the polyethylene yarn may have a density of 0.93 to 0.97 g/cm ³ and a degree of crystallinity through spinning of 50 to 90%, specifically 60 to 85%. The crystallinity degree of the polyethylene yarn can be derived along with the crystallite size when analyzing crystallinity using an X-ray diffraction analyzer. As described above, in the range where the crystallinity satisfies the above range, heat is rapidly diffused and dissipated through lattice vibration called 'phonon' in the direction of the molecular chain connected through covalent bonds of high-density polyethylene (HDPE). The moisture discharge function, such as sweat and breath, is improved, thereby providing a fabric with excellent wearing comfort.

Hereinafter, a method for manufacturing polyethylene yarn according to an aspect of the present invention will be described in detail with reference to FIG. 1. The polyethylene yarn of the present invention is not limited in its manufacturing method as long as it satisfies the range of the above-mentioned physical properties such as PDI, strength, and elongation at maximum strength. One aspect is described below.

First, polyethylene in the form of chips is put into an extruder 100 and melted to obtain a polyethylene melt.

Molten polyethylene is transported through the spinneret 100 by a screw (not shown) in the extruder 100 and is extruded through a plurality of holes formed in the spinneret 200. The number of holes in the spinneret 200 may be determined depending on the DPF (Denier Per Filament) and fineness of the yarn to be manufactured. For example, when manufacturing yarn with a total fineness of 75 denier, the spindle 200 may have 20 to 75 holes, and when manufacturing yarn with a total fineness of 450 denier, the spinneret 200 may have 20 to 75 holes. It may have 90 to 450 holes, preferably 100 to 400 holes.

The melting process within the extruder 100 and the extrusion process through the die 200 can be changed depending on the melt index of the polyethylene chip, but specifically, for example, 150 to 315 ° C., preferably 250 to 315 ° C. More preferably, it is carried out at 265 to 310°C. That is, it is preferable that the extruder 100 and the spinneret 200 are maintained at 150 to 315°C, preferably 250 to 315°C, and more preferably 265 to 310°C.

If the spinning temperature is less than 150°C, spinning may be difficult because the polyethylene is not uniformly melted due to the low spinning temperature. On the other hand, if the spinning temperature exceeds 315°C, thermal decomposition of polyethylene may occur and the desired strength may not be achieved.

L/D, which is the ratio of the hole length (L) to the hole diameter (D) of the spinneret 200, may be 3 to 40. If L/D is less than 3, die swell phenomenon occurs during melt extrusion and it becomes difficult to control the elastic behavior of polyethylene, resulting in poor spinability. If L/D exceeds 40, it passes through the spinneret 200. In addition to thread breakage due to the necking phenomenon of molten polyethylene, discharge unevenness due to pressure drop may occur.

As the molten polyethylene is discharged from the holes of the spinneret 200, solidification of the polyethylene begins due to the difference between the spinning temperature and room temperature, and the filaments 11 in a semi-solidified state are formed. In this specification, both fully solidified filaments as well as semi-solidified filaments are collectively referred to as “filaments.”

The plurality of filaments 11 are completely solidified by cooling in a cooling zone (or “quenching zone”) 300. Cooling of the filaments 11 may be performed by air cooling.

The cooling of the filaments 11 in the cooling unit 300 is preferably performed to 15 to 40° C. using cooling wind with a wind speed of 0.2 to 1 m/sec. If the cooling temperature is less than 15 ℃, the elongation may be insufficient due to supercooling, which may cause thread breakage during the stretching process. If the cooling temperature exceeds 40 ℃, the fineness deviation between the filaments 11 increases due to non-uniform solidification and the stretching process may occur. Defects may occur.

In addition, by performing multi-stage cooling during cooling in the cooling unit, crystallization can be achieved more uniformly, thereby facilitating the discharge of moisture and sweat, and producing yarn with excellent cold sensitivity. More specifically, the cooling unit may be divided into three or more sections. For example, in the case of three cooling sections, it is desirable to design the temperature to gradually decrease from the first cooling section to the second cooling section. Specifically, for example, the first cooling unit may be set to 50 to 80 °C, the second cooling unit may be set to 30 to 50 °C, and the third cooling unit may be set to 15 to 30 °C.

Additionally, by setting the wind speed to the highest in the first cooling unit, fibers with a smoother surface can be manufactured. Specifically, the first cooling unit is cooled to 50 to 80 ℃ using cooling wind with a wind speed of 1.0 to 1.5 m/sec, and the second cooling unit is cooled to 30 to 50 ℃ using cooling wind with a wind speed of 0.6 to 1.0 m/sec. cooling, and the third cooling unit may be cooled to 15 to 30 ℃ using cooling wind with a wind speed of 0.3 to 0.6 m/sec. By controlling these conditions, yarn with higher crystallinity and a smoother surface can be produced. It can be manufactured.

Next, the cooled and completely solidified filaments 11 are collected using the focuser 400 to form the multifilament 10.

As illustrated in Figure 1, the polyethylene yarn of the present invention can be manufactured through a direct spin stretching (DSD) process. That is, the multifilament 10 is directly transferred to the multi-stage stretching unit 500 including a plurality of godet roller units (GR1...GRn) and multi-stage stretching at a total stretching ratio of 2 to 20, preferably 3 to 15 times. After that, it can be wound on the winder 600. In addition, by providing 1 to 5% shrinkage and stretching (relaxation) in the last stretching section during multi-step stretching, it is possible to provide yarn with more excellent durability.

Alternatively, the polyethylene yarn of the present invention may be manufactured by first winding the multifilament 10 as an undrawn yarn and then stretching the undrawn yarn. That is, the polyethylene yarn of the present invention may be manufactured through a two-step process of first manufacturing undrawn yarn by melt spinning polyethylene and then stretching the undrawn yarn.

If the total draw ratio applied in the stretching process is less than 2, the final polyethylene yarn cannot have a crystallinity of more than 60%, and there is a risk of causing pilling on the fabric made from the yarn.

On the other hand, if the total elongation ratio exceeds 15 times, there is a possibility that thread breakage may occur, and the strength of the final polyethylene yarn is not suitable, so not only is the weaving property of the polyethylene yarn poor, but the fabric manufactured using it is too stiff. Users may feel uncomfortable.

Once the linear speed of the first godet roller unit (GR1), which determines the spinning speed of the melt spinning of the present invention, is determined, a total draw ratio of 2 to 20, preferably 3 to 15, in the multi-stage stretching unit 500 is set to the multi-stage stretching unit 500. To be applied to the filament 10, the linear speeds of the remaining godet roller parts are appropriately determined.

According to one embodiment of the present invention, polyethylene is formed through the multi-stage stretching unit 500 by appropriately setting the temperature of the godet roller parts (GR1...GRn) of the multi-stage stretching unit 500 in the range of 40 to 140 ° C. Heat-setting of the yarn may be performed. Specifically, for example, the multi-stage stretching section may be composed of three or more stretching sections, specifically 3 to 5 stretching sections. Additionally, each stretching section may be comprised of multiple godet roller units.

Specifically, for example, the multi-stage stretching section may be composed of four stretching sections, and after stretching to a total stretching ratio of 2 to 15 times in the first to fourth stretching sections, shrinkage and stretching by 1 to 3% in the fifth stretching section. It may be to perform (relaxation). The total draw ratio refers to the final draw ratio of the fiber that has passed from the first stretching section to the third stretching section compared to the fiber before stretching.

More specifically, the first stretching section may be performed at 40 to 80° C., and the stretching ratio of the first stretching section may be 1.5 to 3 times. The second stretching section may be performed at a higher temperature than the first stretching section, specifically at 80 to 130° C., and may be stretched so that the stretching ratio of the second stretching section is 1.05 to 3 times. The third stretching section may be performed at 100 to 150° C. and may be stretched so that the stretching ratio is 1.05 to 3 times. The fourth stretching section may be performed at the same or lower temperature as the second stretching section, and specifically, may be performed at 80 to 140° C. and may perform 1 to 3% shrinkage stretching (relaxation).

Multi-stage stretching and heat setting of the multi-filament 10 are simultaneously performed by the multi-stage stretching unit 500, and the multi-stage stretched multifilament 10 is wound on the winder 600, thereby completing the polyethylene yarn of the present invention.

The functional fabric according to the present invention includes the above-described polyethylene yarn. As it contains polyethylene yarn with excellent thermal conductivity and high weaving properties, it has cooling characteristics and has fewer defects such as wool, so it can have excellent quality. . In addition, as the functional fabric contains the above-mentioned polyethylene yarn, it not only has a cooling sensation but also has excellent drape properties, so when the user wears a product made from such fabric, the contact area between the user and the product is high, which is substantially superior. It can have a cooling effect.

The functional fabric according to the present invention may be made by using the above-described polyethylene yarn alone, and may further include heterogeneous yarns to further provide other functionalities, but from the viewpoint of having cold sensitivity and weaving properties at the same time, the polyethylene yarn may be used alone. It is preferable to use the yarn alone.

Specifically, the functional fabric has a contact cooling value of 0.15 to 0.45 W/measured by contacting the fabric at 20±2℃ with a heat plate (T-box) at 30±2℃ at 20±2℃, 65±2% R.H. ㎠, and the thermal conductivity in the thickness direction can be 0.01 to 0.30 W/mK at 20°C by contacting a heat source plate (BT-box) at 30±2°C with the fabric at 20±2°C. More specifically, contact cooling may be 0.18 to 0.30 W/cm2, and thermal conductivity in the thickness direction may be 0.05 to 0.2 W/mK. When functional fabrics with such a cooling sensation are later manufactured or processed into products and worn by a user, they can provide an appropriate cooling sensation that allows the user to feel comfortable in a high-temperature environment.

In addition, the functional fabric may have a wool occurrence of 10 or less per 100,000 ㎡, specifically, 8 or less. In other words, functional fabrics can be manufactured with high quality by containing polyethylene yarns with improved weaving properties.

The functional fabric may be a woven or knitted fabric having a weight per unit area (i.e., area density) of 150 to 800 g/m2. If the areal density of the fabric is less than 150 g/m2, the density of the fabric is insufficient and many voids exist within the fabric, and these voids reduce the cold sensitivity of the fabric. On the other hand, if the areal density of the fabric exceeds 800 g/㎡, the fabric becomes stiff due to an overly dense fabric structure, problems with the tactile sensation felt by the user occur, and problems in use occur due to the high weight.

Such fabrics can be processed into cold-sensitive products that require appropriate cold sensitivity. The product can be any conventional textile product, but preferably it can be summer summer clothes, sportswear, masks, and work clothes to provide cold sensitivity to the human body.

As the cool-sensitive product of the present invention is manufactured from the above-described fabric, it has a low stiffness of 5 gf or less, more preferably 2 to 5 gf, and has excellent drapability and excellent wearing comfort. In addition, as it exhibits excellent drape properties, when the user wears it, the contact area with the user's body is high, so it can have a substantially better cooling effect.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only a reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

Additionally, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. The terminology used in the description herein is merely to effectively describe particular embodiments and is not intended to limit the invention. Additionally, the unit of additives not specifically described in the specification may be weight percent.

The physical properties were measured as follows.

[Measurement of yarn properties]

<1. Weight distribution graph, weight average molecular weight (Mw) (g/mol) and polydispersity index (PDI)>

After completely dissolving the polyethylene yarn in the solvent below, use the following gel permeation chromatography (GPC) to obtain a weight distribution graph, weight average molecular weight (Mw), and polydispersity index (Mw/Mn: PDI) of the polyethylene yarn, respectively. Saved.

- Analysis device: Tosoh HLC-8321 GPC/HT

- Column: PLgel guard (7.5 x 50 mm) + 2 x PLgel mixed-B (7.5 x 300 mm)

- Column temperature: 160 ℃

- Solvent: Trichlorobenzene (TCB) + 0.04 wt.% dibutylhydroxytoluene (BHT) (after drying with 0.1% CaCl2)

- Injector, detector temperature: 160 ℃

- Detector: RI Detector

- Flow rate: 1.0 ㎖/min

- Injection volume: 300 mL

- Sample concentration: 1.5 mg/mL

- Standard sample: polystyrene

<2. Strength (g/d), initial modulus (g/d), and elongation (%)>

According to the ASTM D2256 method, the strain-stress curve of polyethylene yarn was obtained using a universal tensile tester from Instron Engineering Corp. (Canton, Mass.). The sample length was 250 mm, the tensile speed was 300 mm/min, and the initial load was set at 0.05 g/d. Strength (g/d) and elongation (%) at maximum strength were obtained from the stress and elongation at the breaking point, and the initial modulus (g/d) was obtained from the tangent line giving the maximum gradient near the origin of the curve. . Each yarn was measured 5 times and the average value was calculated.

<3. Crystallinity>

The crystallinity of polyethylene yarn was measured using an XRD device (X-ray Diffractometer) [manufacturer: PANalytical, model name: EMPYREAN]. Specifically, polyethylene yarn was cut to prepare a sample with a length of 2.5 cm, the sample was fixed to a sample holder, and measurement was performed under the conditions below.

- Light source (X-ray Source): Cu-Kα radiation

- Power: 45 KV x 25 mA

- Mode: Continuous scan mode

- Scan angle range: 10~40°

- Scan speed: 0.1°/sec

[Measurement of fabric properties]

<1. Contact cold feeling>

We commissioned the Korea Apparel Testing & Research Institute and measured it using a KES-F7 (Thermo Labo II) device in a test environment of 20 ± 2 ℃, 65 ± 2 % R.H.

Specifically, a fabric sample measuring 20cmХ20cm was prepared and left for 24 hours under conditions of a temperature of 20±2°C and RH of 65±2%. Next, the contact cooling sensation (Q max) of the fabric was measured using a KES-F7 THERMO LABO Ⅱ (Kato Tech Co., LTD.) device in a test environment of 20 ± 2°C and 65 ± 2% RH. Specifically, as illustrated in Figure 2, the fabric sample 23 is placed on a base plate (also referred to as 'Water-Box') 21 maintained at 20 ° C, and a hot plate heated to 30 ° C ( T-Box, 22a) (contact area: 3cmХ3cm) was placed on the fabric sample 23 for only 1 second. That is, the other side of the fabric sample 23, whose one side is in contact with the base plate 21, was momentarily brought into contact with the T-Box 22a. The contact pressure applied to the fabric sample 23 by the T-Box 22a was 6 gf/cm2. Subsequently, the Q max value displayed on the monitor (not shown) connected to the device was recorded. This test was repeated 10 times, and the arithmetic mean of the Q max value was calculated.

<2. Thermal conductivity>

A fabric sample measuring 20cmХ20cm was prepared and left for 24 hours at a temperature of 20±2°C and RH of 65±2%. Next, the thermal conductivity and heat transfer coefficient of the fabric were obtained using a KES-F7 THERMO LABO Ⅱ (Kato Tech Co., LTD.) device in a test environment of 20 ± 2°C and 65 ± 2% RH. Specifically, as illustrated in Figure 3, the fabric sample 23 is placed on the base plate 21 maintained at 20°C, and a heat source plate (BT-Box, 22b) at 30±2°C (contact area : 5cmХ5cm) was placed on the fabric sample 23 for 1 minute. Heat was continuously supplied to the BT-Box (22b) so that its temperature was maintained at 30°C even while the BT-Box (22b) was in contact with the fabric sample 23. The amount of heat (i.e., heat flow loss) supplied to maintain the temperature of the BT-Box (22b) was displayed on a monitor (not shown) connected to the device. This test was repeated five times, and the arithmetic mean of heat flow loss was calculated. Next, the thermal conductivity and heat transfer coefficient of the fabric were calculated using Equations 2 and 3 below.

Equation 2: K = (W·D)/(A·ΔT)

Equation 3: k = K/D

Here, K is the thermal conductivity (W/cm·°C), D is the thickness of the fabric sample 23 (cm), A is the contact area of the BT-Box (22b) (=25 cm2), and ΔT is The temperature difference between both sides of the fabric sample 23 (= 10°C), W is the heat flow loss (Watt), and k is the heat transfer coefficient (W/cm2·°C).

<3. Stiffness(gf)>

After collecting a fabric sample (width: 60mm, height: 60mm), the stiffness of the specimen was measured according to section 38 of ASTM D885/D885M-10a (2014). The measuring device was as follows.

(i) CRE-type Tensile Testing Machine (model: INSTRON 3343)

(ii) Loading Cell, 2 KN [200 kgf]

(iii) Specimen Holder: Specimen holder as specified in section 38.4.3.

(iv) Specimen Depressor: Specimen depressor as defined in section 38.4.4.

Specifically, the sample was placed in the center of the specimen holder so that the sample was directly supported by the specimen holder. The sample remained flat without bending. At this time, the distance between the specimen supporting part of the specimen holder and the depressing part of the specimen depressor was 5 mm. Next, the maximum force was measured while raising the specimen holder to 15 mm while leaving the specimen depressor still.

[Example 1]

<Manufacture of polyethylene yarn>

Polyethylene yarn containing 200 filaments and having a total fineness of 150 denier was manufactured using the device illustrated in FIG. 1.

Specifically, the polyethylene chip was put into the extruder 100 and melted. Molten polyethylene was extruded through a spindle 200 having 200 holes. L/D, which is the ratio of the hole length (L) to the hole diameter (D) of the spinneret 200, was 6. Detention temperature was 270°C.

The filaments 11 formed while being discharged from the nozzle holes of the spinneret 200 were sequentially cooled in the cooling section 300 consisting of three sections. In the first cooling part, it was cooled to 70 ℃ by a cooling wind with a wind speed of 1.2 m/sec, in the second cooling part it was cooled to 40 ℃ by a cooling wind with a wind speed of 0.8 m/sec, and in the third cooling part, it was cooled to 70 ℃ by a cooling wind with a wind speed of 0.8 m/sec. It was finally cooled to 20°C by cooling wind at a wind speed of m/sec. After cooling, it was collected into multifilament yarn 10 by the collector 400.

Subsequently, the multifilament yarn was moved to the stretching unit 500. The stretching section consists of a multi-step stretching section consisting of four sections. Specifically, the first stretching section is stretched at a total stretching ratio of 1.5 times at a maximum stretching temperature of 70°C, and the second stretching section is stretched at a total stretching ratio of 2.0 times at a maximum stretching temperature of 100°C. Stretched, the third stretching section is stretched at a total stretching ratio of 1.5 times at a maximum stretching temperature of 120°C, and the fourth stretching section is stretched and stretched (relaxed) by 2% compared to the third stretching section at a maximum stretching temperature of 125°C. Fixed.

Subsequently, the stretched multifilament yarn was wound on a winder (600). The winding tension was 0.8 g/d.

The physical properties of the manufactured yarn were measured and shown in Table 1 below.

<Manufacture of functional fabric>

The polyethylene yarn prepared above was woven to produce a functional fabric with a surface density of 500 g/m2. The physical properties of the manufactured functional fabric were measured and shown in Table 3 below.

[Examples 2 to 7]

Fabric was manufactured in the same manner as in Example 1, except that the yarn conditions were changed as shown in Table 1 below. In addition, the physical properties of the fabric manufactured in the same manner as in Example 1 were measured and shown in Table 3 below.

[Comparative Examples 1 to 4]

Fabric was manufactured in the same manner as Example 1, except that the yarn conditions were changed as shown in Table 2 below. In addition, the physical properties of the fabric manufactured in the same manner as in Example 1 were measured and shown in Table 4 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Physical properties of yarn PDI 12.4 8.1 15.2 12.4 12.2 12.3 12.7 Mw (g/mol) 82,786 128,531 147,452 114,551 916,331 79,321 83,214 (Mw _max - Mw _aver ) -
(Mw _aver - Mw _min ) -0.13 -0.10 -0.12 -0.15 -0.70 0.11 0.15 Crystallinity (%) 75.1 75.6 74.2 75.3 75.8 71.2 69.5 Strength (g/d) 7.2 8.2 8.8 7.5 7.3 5.7 5.8 Initial Modulus (g/d) 50.2 72.7 79.1 68.5 64.1 75.7 73.4 Elongation (%) 28.4 19.7 15.2 22.7 25.5 11.2 13.4

division Comparative Example 1 Comparative example 2 Comparative Example 3 Comparative example 4 Physical properties of polyethylene yarn PDI 9.6 9.5 7.7 5.0 Mw(g/mol) 188,214 174,562 168,461 365,164 (Mw _max - Mw _aver ) - (Mw _aver - Mw _min ) 0.05 0.12 0.07 0.14 Crystallinity (%) 75.1 75.5 73.1 76.0 Strength (g/d) 13.8 13.0 12.7 15.5 Initial Modulus (g/d) 160 203 141 300 Elongation (%) 9.4 9.0 9.8 6.5

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Physical properties of functional fabrics Cold sensation on contact
(W/㎠) 0.208 0.207 0.210 0.202 0.248 0.198 0.192 Thickness direction thermal conductivity at 20℃
(W/mK) 0.163 0.161 0.163 0.151 0.188 0.124 0.134 Lecture too
(g/d) 3.1 3.2 3.4 4.2 4.3 5.7 4.8 100,000㎡ Frequency of occurrence of each cow 2 3 2 One 3 6 7

Comparative Example 1 Comparative example 2 Comparative example 3 Comparative example 4 Physical properties of functional fabrics Contact cooling sensation (W/㎠) 0.112 0.115 0.082 0.092 Thickness direction thermal conductivity at 20℃ (W/mK) 0.09 0.12 0.07 0.13 Hardness (g/d) 6.1 7.8 7.8 7.1 100,000㎡ Frequency of occurrence of hair loss 13 20 17 11

Referring to Tables 1 to 4 above, it was confirmed that the fabric according to the example had an appropriate cooling sensation and excellent drape properties with excellent stiffness, and that the frequency of hair generation during fabric manufacturing was extremely low, resulting in excellent weaving properties. In particular, referring to Figure 4, which shows a weight distribution graph through GPC analysis of Example 3, an example that satisfies Equation 1 above, that is, (Mw _max - Mw _aver ) - (Mw _aver - Mw _min ) In the example where the value of was negative, it was confirmed that it had better weaving properties and cold sensitivity. As described above, the present invention has been described with specific details, limited embodiments, and drawings, but these are provided only to facilitate a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and the present invention Anyone skilled in the art can make various modifications and variations from this description.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and the scope of the patent claims described below as well as all modifications that are equivalent or equivalent to the scope of this patent claim shall fall within the scope of the spirit of the present invention. .

100: Extruder
200: Detention
300: Cooling unit
400: Focusing unit
500: stretching section
600: Winder

Claims (12)

A polyethylene yarn having a polydispersity index (PDI) of 5 or more and 20 or less, a strength measured according to ASTM D2256 of 1.5 to 10 g/d, and an elongation at maximum strength of 10 to 50%. According to paragraph 1,
The polyethylene yarn is
The weight distribution graph through gel filtration chromatography (GPC) analysis, where the log scale of molecular weight (Mw) is on the x-axis and the weight distribution (dw/dLogM) on the y-axis, satisfies the following equation 1, and the weight distribution graph is Unimodal, polyethylene yarn.
[Equation 1]
(Mw _max - Mw _aver ) < (Mw _aver - Mw _min )
(In the above formula, Mw _aver is the molecular weight with the maximum weight distribution in the weight distribution graph, and Mw _max and Mw _min mean the two molecular weights corresponding to 0.25Q in the weight distribution graph with respect to the weight distribution value Q in Mw _aver . (Mw _maw refers to the maximum value of the two molecular weights, and Mw _min refers to the minimum value.) According to paragraph 1,
The yarn is a polyethylene yarn having an initial modulus of 30 to 80 d/g as measured according to ASTM 2256. According to paragraph 1,
The yarn is a polyethylene yarn with a crystallinity of 65 to 85%. According to paragraph 1,
The yarn is a polyethylene yarn with a density of 0.93 to 0.97 g/cm ³ . According to paragraph 1,
The yarn is a polyethylene yarn having a weight average molecular weight of 90,000 to 400,000 g/mol. A functional fabric comprising the polyethylene yarn of any one of claims 1 to 6. In clause 7,
The fabric has a contact coldness of 0.18 to 0.30 W/cm2, which is measured at 20±2℃, 65±2% RH, by contacting the fabric at 20±2℃ with a heat plate (T-box) at 30±2℃. Functional fabric. In clause 7,
The fabric has a thickness direction thermal conductivity of 0.05 at 20±2℃ and 65±2% RH, as measured by contacting a heat source plate (BT-box) at 30±2℃ with respect to the fabric at 20±2℃. Functional fabric with a power of 0.20 W/mK. In clause 7,
The fabric is a functional fabric in which the number of hairs generated per 100,000 ㎡ is 10 or less. In clause 7,
The fabric is a functional fabric with a surface density of 150 to 800 g/m2. A cold-sensitive product manufactured from the fabric of claim 7.