KR20200036171A - Polyethylene Yarn, Method for Manufacturing The Same, and Skin Cooling Fabric Comprising The Same - Google Patents

Abstract

Disclosed are polyethylene yarn which provides soft touch as well as skin cooling and provides increased weavability properties allowing manufacturing of skin cooling fabric with excellent pilling resistance, abrasion resistance, cuttability, and sewability, a manufacturing method thereof, and skin cooling fabric including the same. According to the present invention, in a strength and elongation curve of the polyethylene yarn acquired by measurement at room temperature, (i) elongation at a strength of 1 g/d is 0.5 to 3%, (ii) elongation at a strength of 3 g/d is 5.5 to 10%, and (iii) an elongation difference between elongation at strength of 4 g/d and elongation at a strength maximum is 5.5 to 25%. Moreover, the polyethylene yarn has a toughness of 55 to 120 J/m^3 at room temperature.

Description

Polyethylene yarn, its manufacturing method, and a cold-sensitive fabric comprising the same {Polyethylene Yarn, Method for Manufacturing The Same, and Skin Cooling Fabric Comprising The Same}

The present invention relates to a polyethylene yarn, a manufacturing method thereof, and a cold-sensitive fabric comprising the same, and more specifically, provides a user with a soft tactile sensation as well as a cooling feeling or a cooling sensation. Polyethylene yarn with improved weavability, which enables the manufacture of cold-sensitive fabrics with excellent pilling resistance, abrasion resistance, cuttability and sewability, It relates to a manufacturing method and a cold-sensitive fabric comprising the same.

As global warming progresses, the need for fabrics that can be used to overcome the heat is increasing. Factors that may be considered in developing fabrics that can be used to overcome heat, include (i) removal of heat factors, and (ii) heat removal from user skin.

As a method focused on the elimination of heat and heat factors, a method of reflecting light by imparting an inorganic compound to the fiber surface (see, for example, JP 4227837B), and a method of scattering light by dispersing inorganic fine particles inside and on the fiber ( For example, JP 2004-292982A) has been proposed. However, blocking of such external factors can only prevent additional heat, and may not be a meaningful solution for users who already feel the heat, but also has a limitation in that the texture of the fabric is deteriorated.

On the other hand, as a method to remove heat from the user's skin, a method of improving the hygroscopicity of the fabric to use the heat of evaporation of sweat (for example, see JP 2002-266206A), increasing the heat transfer from the skin to the fabric For this, a method of increasing the contact area between the skin and the fabric (for example, see JP 2009-24272A) has been proposed.

However, in the case of the method using the heat of evaporation of sweat, since the function of the fabric is highly dependent on external factors such as humidity and user's constitution, there is a problem that its consistency cannot be guaranteed, and a method of increasing the contact area between the skin and the fabric In the case of, since the air permeability of the fabric decreases as the contact area increases, a desired cooling effect cannot be obtained.

Therefore, it may be desirable to increase heat transfer from the skin to the fabric by improving the thermal conductivity of the fabric itself. To this end, JP 2010-236130A proposes to fabricate fabrics using ultra high strength polyethylene fibers (Dyneema ^® SK60) with high thermal conductivity.

However, the Dyneema ^® SK60 fiber used in JP 2010-236130A is an Ultra High Molecular Weight Polyethylene (UHMWPE) fiber having a weight average molecular weight of 600,000 g / mol or more, although it exhibits high thermal conductivity (i ) Due to the high melt viscosity of UHMWPE, it can only be produced by the gel spinning method, causing environmental problems and high cost of recovery of organic solvents. (Ii) Higher than 28 g / d The strength, 759 g / d or higher tensile modulus, and a low elongation at break of 3-4% and elongation at 1 g / d strength in the stiffness curve are less than 0.5%, so the weavability is poor and its strength ( because stiffness) is so high and not suitable for use in the production of cold-sensitivity fabric that assumes contact with the user's skin, (iii) has high toughness (toughness) in excess of 120 J / m ³ There is a problem that the Foundation Castle and the sewing of the fabric produced by the degradation.

Accordingly, the present invention relates to a polyethylene yarn capable of preventing problems caused by limitations and disadvantages of the related art as described above, a manufacturing method thereof, and a cold-sensitive fabric comprising the same.

One aspect of the present invention, as well as cool or cold feeling, can provide the user with a soft touch, and provides a polyethylene yarn with improved weavability that enables the manufacture of fabrics with excellent peeling resistance, abrasion resistance, cutability and sewing properties. Is to do.

Another aspect of the present invention is to produce a polyethylene yarn having improved weavability that can provide a user with a feeling of coolness or cold as well as a soft touch and has excellent peeling resistance, abrasion resistance, cutability and sewing properties. Is to provide a way to do it.

Another aspect of the present invention is to provide a fabric having excellent feeling of peeling resistance, abrasion resistance, cutability and sewing, which can provide a user with a soft feel as well as a cool or cold feeling.

In addition to the above-mentioned aspects of the present invention, other features and advantages of the present invention will be described below, or it will be clearly understood by those skilled in the art from the description.

According to one aspect of the present invention as described above, as a polyethylene yarn, in the elongation curve of the polyethylene yarn obtained by measuring at room temperature, (i) elongation at a strength of 1 g / d is 0.5 to 3%, and (ii) 3 Elongation at the strength of g / d is 5.5 to 10%, (iii) the difference between elongation at 4 g / d strength and elongation at maximum strength is 5.5 to 25%, and the polyethylene yarn is 55 to 120 at room temperature. A polyethylene yarn having a toughness of J / m ³ is provided.

The polyethylene yarn may have a tensile strength of more than 4 g / d and 6 g / d or less, a tensile modulus of 15 to 80 g / d, an elongation at break of 14 to 55%, and a crystallinity of 60 to 85%.

The polyethylene yarn may have a weight average molecular weight (Mw) of 50,000 to 99,000 g / mol and a polydispersity index (PDI) of 5 to 9.

The polyethylene yarn may have a total fineness of 75 to 450 denier, and the polyethylene yarn may include a plurality of filaments each having a fineness of 1 to 5 denier.

The polyethylene yarn may have a circular cross section.

According to another aspect of the present invention, as the cold-sensitive fabric formed of the polyethylene yarn, the cold-sensitive fabric at 20 ° C is 0.0001 W / cm · ° C or more in the thickness direction thermal conductivity, 0.001 W / cm ² · ° C or more in the thickness direction heat transfer coefficient , And 0.1 W / cm ² or more, having a contact cooling feeling (Q _max ).

The peeling resistance of the cold-sensitive fabric measured according to ASTM D 4970-07 may be 4 or higher, and the cold-sensitive fabric measured according to the Martindale method defined in KS K ISO 12947-2: 2014. Abrasion resistance can be over 5000 cycles.

The surface density of the cold-sensitive fabric may be 75 to 800 g / m ² .

According to another aspect of the invention, a density of 0.941 to 0.965 g / cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g / mol, a polydispersity index (PDI) of 5.5 to 9, and 6 to 21 g / Melting polyethylene having a melt index (MI) of 10 min (at 190 ° C.); Extruding the molten polyethylene through a custody having a plurality of holes; Cooling the plurality of filaments formed when the molten polyethylene is discharged from the holes of the custody; And stretching the multifilament made of the cooled filaments.

The stretching step may be performed at a stretching ratio of 2.5 to 8.5.

The general description of the present invention as described above is only for illustrating or describing the present invention, and does not limit the scope of the present invention.

The polyethylene yarn for cold-sensitive fabric of the present invention has high thermal conductivity, toughness adjusted to an appropriate range, and excellent weavability, and can be easily produced at relatively low cost without causing environmental problems.

In addition, the cold-sensitive fabric woven from the polyethylene yarn of the present invention can (i) consistently provide cooling to the user irrespective of external factors such as humidity, and (ii) sufficient cooling to the user without sacrificing breathability. Can be provided, (iii) can provide a soft touch to the user, (iv) has a high peeling resistance and abrasion resistance, thereby improving the durability of the final product, and (v) excellent cutting and sewing properties. By having, it is possible to improve the productivity of the final product.

The accompanying drawings are intended to help the understanding of the present invention and constitute a part of the present specification, and exemplify embodiments of the present invention, and describe the principles of the present invention together with a detailed description of the present invention.
Figure 1 schematically shows a polyethylene yarn manufacturing apparatus according to an embodiment of the present invention,
Figure 2 schematically shows a device for measuring the contact cooling (Q _max ) of the cold-sensitive fabric,
3 schematically shows an apparatus for measuring the thermal conductivity and heat transfer coefficient in the thickness direction of a cold-sensitive fabric.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments described below are presented for illustrative purposes only to aid in a clear understanding of the present invention, and do not limit the scope of the present invention.

In order to allow the user to feel a sufficient cooling feeling, it is preferable that the yarns used in the manufacture of the cold-sensing fabric are polymer yarns having high thermal conductivity.

In the case of solids, in general, heat is transferred through the movement of free electrons and lattice vibrations called 'phonon'. In the case of metal, heat is transferred in a solid mainly by the movement of free electrons. On the other hand, in the case of a non-metallic material such as a polymer, heat is mainly transferred through a phonon in a solid (especially in the direction of a molecular chain connected through a covalent bond).

In order to improve the thermal conductivity of the fabric so that the user can feel a sufficient cooling feeling, it is necessary to enhance the heat transfer ability through the phonon of the polymer yarn by increasing the crystallinity of the polymer yarn to 60% or more.

According to the present invention, high-density polyethylene (HDPE) is used to produce a polymer yarn having such high crystallinity. 0.941 to 0.965 g / compared to yarns made of low density polyethylene (LDPE) with a density of 0.910 to 0.925 g / cm ³ and yarns made of linear low density polyethylene (LLDPE) with a density of 0.915 to 0.930 g / cm ³ This is because yarns made of high density polyethylene (HDPE) having a density of cm ³ have a relatively high crystallinity.

Meanwhile, high-density polyethylene (HDPE) yarns may be classified into ultra high molecular weight polyethylene (UHMWPE) yarns and high molecular weight polyethylene (HMWPE) yarns according to their weight average molecular weight (Mw). UHMWPE generally refers to linear polyethylene having a weight average molecular weight (Mw) of at least 600,000 g / mol, while HMWPE generally refers to linear polyethylene having a weight average molecular weight (Mw) of 20,000 to 250,000 g / mol. .

As described above, since UHMWPE yarns such as Dyneema ^® can be produced only by a gel spinning method due to the high melt viscosity of UHMWPE, there is a problem that environmental problems are caused and it takes a great cost to recover the organic solvent.

Since HMWPE has a relatively low melt viscosity compared to UHMWPE, melt spinning is possible, and as a result, environmental problems and high cost problems associated with UHMWPE yarns can be overcome. Therefore, the polyethylene yarn for cold-sensitive fabric of the present invention is a yarn formed of HMWPE.

In the elongation curve of the polyethylene yarn of the present invention obtained by measuring at ambient temperature, (i) "elongation at strength of 1 g / d" is 0.5 to 3%, and (ii) strength of "3 g / d Elongation at ”is 5.5 to 10%, and (iii)“ Difference between elongation at 4 g / d strength and elongation at maximum strength (ie tensile strength) ”is 5.5 to 25%. In addition, the polyethylene yarn of the present invention has a toughness of 55 to 120 J / m ³ at room temperature.

If the "elongation at strength of 1 g / d" of the polyethylene yarn is less than 0.5%, the fabric woven from the yarn is too stiff (i.e., the ductility of the fabric is too high), causing a bad touch to the user. On the other hand, if the "elongation at the strength of 1 g / d" of the polyethylene yarn exceeds 3%, the phenomenon that the yarn increases when weaving the fabric occurs, thereby setting the density of the fabric to the required density. it's difficult.

When the "elongation at the strength of 3 g / d" of the polyethylene yarn is less than 5.5%, there is a high risk of thread trimming in the fabric weaving process in which a predetermined size of tension is applied. On the other hand, when the "elongation at the strength of 3 g / d" of the polyethylene yarn exceeds 10%, crimps are insufficiently expressed when weaving the fabric, resulting in a fabric having low tear strength and low durability. do.

The toughness is the area (integral value) between the elongation curve (x-axis: elongation, y-axis: intensity) and the x-axis, and becomes larger as the difference between elongation at 4 g / d intensity and elongation at maximum intensity is greater. Have a tendency

If the "difference between elongation at 4 g / d strength and elongation at maximum strength" of the polyethylene yarn is less than 5.5% or the toughness of the polyethylene yarn is less than 55 J / m ³ , the peeling resistance of the fabric woven from the yarn And wear resistance is not satisfactory. That is, the polyethylene yarn has a toughness of 5.5% or more, "difference between elongation at 4 g / d strength and elongation at maximum strength" and toughness of 55 J / m ³ or higher, and the cold-sensitive fabric produced using the same is grade 4 It can have an ideal peeling resistance (measured according to ASTM D 4970-07) and a wear resistance of 5000 cycles or more (measured according to the Martindale method specified in KS K ISO 12947-2: 2014).

On the other hand, if the "difference between elongation at 4 g / d strength and elongation at maximum strength" of the polyethylene yarn exceeds 25% or the toughness of the polyethylene yarn exceeds 120 J / m ³ , the yarn is woven into the yarn. The productivity of the final product is lowered due to the poor cutting and sewing properties of the fabric, and the use of expensive special cutting and sewing machines to overcome this leads to an increase in production cost.

In addition, the polyethylene yarn according to an embodiment of the present invention has a tensile strength of more than 4 g / d and 6 g / d or less, a tensile modulus of 15 to 80 g / d, a elongation at break of 14 to 55%, and 60 to 85% Has a crystallinity of

If the tensile strength exceeds 6 g / d, the tensile modulus exceeds 80 g / d, or the elongation at break is less than 14%, the weavability of the polyethylene yarn is not only poor, but the fabric produced using it is too stiff As a result, the user feels uncomfortable. Conversely, if the tensile strength is 4 g / d or less, the tensile modulus is less than 15 g / d, or the elongation at break exceeds 55%, the lint may be applied to the fabric if the user continuously uses fabrics made from these polyethylene yarns. pills), and even fabric breakage.

If the crystallinity of the polyethylene yarn is less than 60%, its thermal conductivity is low, and the fabric made of it cannot provide a sufficient cooling feeling to the user. That is, by having the crystallinity of the polyethylene yarn 60 to 85%. The cold-sensitive fabric manufactured using this, at 20 ° C, has a thickness direction thermal conductivity of 0.0001 W / cm · ° C or more, a thickness direction heat transfer coefficient of 0.001 W / cm ² · ° C or more, and a contact cooling feeling of 0.1 W / cm ² or more (Q _max ).

In addition, the polyethylene yarn according to an embodiment of the present invention has a weight average molecular weight (Mw) of 50,000 to 99,000 g / mol and a polydispersity index (PDI) of 5 to 9. The polydispersity index (PDI) is a ratio (Mw / Mn) of a weight average molecular weight (Mw) to a number average molecular weight (Mn), and may also be referred to as a molecular weight distribution index (MWD). The weight average molecular weight (Mw) and polydispersity index (PDI) of polyethylene yarn are closely related to the properties of polyethylene used as the raw material.

The polyethylene yarn of the present invention may have a Denier Per Filament (DPF) of 1 to 5 (ie, the polyethylene yarn may include multiple filaments each having a fineness of 1 to 5 denier). In addition, the polyethylene yarn of the present invention may have a total fineness of 75 to 450 denier.

When the fineness of each filament in the polyethylene yarn having a predetermined total fineness exceeds 5 denier, the smoothness of the fabric made of the polyethylene yarn is insufficient, and the contact area with the body is reduced, thereby providing sufficient cold feeling to the user. Can not. In general, the DPF can be adjusted through the ejection amount per hole of the detention (hereinafter referred to as "single hole discharge amount") and the draw ratio.

The polyethylene yarn of the present invention may have a circular cross-section or a non-circular cross-section, but it is preferable to have a circular cross-section in that it can provide a uniform cooling feeling to a user.

The cold-sensitive fabric of the present invention made of the above-mentioned polyethylene yarn may be a woven fabric or a knitted fabric having a weight per unit area of 75 to 800 g / m ² (ie, surface density). If the cotton density of the fabric is less than 75 g / m ^2, the denseness of the fabric is insufficient and many voids exist in the fabric, and these voids deteriorate the cold feeling of the fabric. On the other hand, if the cotton density of the fabric exceeds 800 g / m ² , the fabric becomes very stiff due to the excessively dense fabric structure, and a user feels a problem, and a high weight causes problems in use.

According to an embodiment of the present invention, the cold-sensitive fabric of the present invention may be a fabric having a cover factor of 400 to 2,000. The cover factor is defined by Equation 1 below.

* Equation 1: CF = W _D · W _T ^1/2 + F _D · F _T ^1/2

Here, CF is the cover factor, W _D is the slope density (ea / inch), W _T is the slope fineness (denier), F _D is the weft density (ea / inch), and F _T is the weft fineness (denier). to be.

If the cover factor of the fabric is less than 400, there is a problem that the density of the fabric is insufficient and the cold feeling of the fabric is deteriorated due to too many pores in the fabric. On the other hand, if the cover factor of the fabric exceeds 2,000, the denseness of the fabric becomes excessively high, resulting in a poor texture and a problem in use due to the high fabric weight.

The cold-sensitive fabric of the present invention, at 20 ° C, has a thickness direction thermal conductivity of 0.0001 W / cm · ° C or more, a thickness direction heat transfer coefficient of 0.001 W / cm ² · ° C or more, and a contact cooling feeling of 0.1 W / cm ² or more (Q _max ). Have The method for measuring the thermal conductivity, heat transfer coefficient, and contact cooling (Q _max ) of the fabric will be described later.

The peeling resistance of the cold-sensitive fabric of the present invention measured according to ASTM D 4970-07 is 4 or higher, and the cold of the present invention measured according to the Martindale method defined in KS K ISO 12947-2: 2014. The wear resistance of sensitive fabrics is over 5000 cycles.

To prepare a polyethylene yarn having the above-described stiffness properties, toughness, tensile strength, tensile modulus, elongation at break, and crystallinity, (i) spinning temperature, (ii) L / D in custody, (iii) of molten polyethylene Process parameters such as the linear velocity of discharge from the custody, (iv) the distance from the custody to the multi-stage stretching section (specifically, the first Godet roller section of the multi-stage stretching section), (v) cooling conditions, and (vi) spinning speed. In addition to these being precisely controlled, it is necessary to select a raw material having properties suitable for the present invention.

Hereinafter, with reference to Figure 1 will be described in detail a method for producing the cold-sensitive polyethylene yarn of the present invention.

First, the polyethylene in the form of a chip is injected into the extruder 100 and melted.

Polyethylene used as a raw material for the production of the polyethylene yarn of the present invention has a density of 0.941 to 0.965 g / cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g / mol, and a melt index of 6 to 21 g / 10min ( MI) (at 190 ° C). In addition, considering that the polydispersity index may decrease in the spinning process, the polyethylene of the present invention used as a raw material has a polydispersity index of 5.5 to 9, which is somewhat higher than the target polydispersity index (ie, the polydispersity index of yarn). (PDI).

In order to manufacture a fabric providing high cold feeling, the polyethylene yarn must have a high crystallinity of 60 to 85%, and to produce a polyethylene yarn having such a high crystallinity, high density polyethylene having a density of 0.941 to 0.965 g / cm ³ (HDPE) is preferred.

When the weight-average molecular weight (Mw) of polyethylene used as a raw material is less than 50,000 g / mol, it is difficult to express a strength and a tensile modulus of more than 15 g / d and a polyethylene yarn that is finally obtained as a polyethylene yarn finally obtained. , Lint is induced in the fabric. Conversely, when the weight average molecular weight (Mw) of the polyethylene exceeds 99,000 g / mol, the weavability of the polyethylene yarn is poor due to excessively high strength and tensile modulus, and its strength is too high to presuppose contact with the user's skin. It is unsuitable for use in the manufacture of cold-sensitive fabrics.

If the polydispersity index (PDI) of polyethylene used as a raw material is less than 5.5, the flowability is poor due to the relatively narrow molecular weight distribution and the processability during melt extrusion is lowered, resulting in thread trimming due to uneven discharge during the spinning process. Conversely, when the PDI of the HDPE exceeds 9, the melt flowability and the processability at the time of melt extrusion are improved due to the wide molecular weight distribution, but the polyethylene yarn finally obtained exceeds 4 g / d because it contains too much low molecular weight polyethylene. It becomes difficult to have strength and tensile modulus of 15 g / d or more, and as a result, lint on the fabric is relatively easily caused.

When the melt index (MI) of polyethylene used as a raw material is less than 6 g / 10min, it is difficult to secure a smooth flowability in the extruder 100 due to the high viscosity and low flowability of the melted polyethylene, and uniformity of the extrudate Due to the reduced formability and processability, the risk of trimming during the spinning process increases. On the other hand, when the melt index (MI) of the polyethylene exceeds 21 g / 10min, the flowability in the extruder 100 becomes relatively good, but the strength of the finally obtained polyethylene yarn exceeds 4 g / d. And 15 g / d or more tensile modulus.

Optionally, a fluorine-based polymer can be added to the polyethylene. As a method for adding a fluorine-based polymer, (i) a master batch containing polyethylene and a fluorine-based polymer is introduced into the extruder 100 together with a polyethylene chip, and then melted therein, or (ii) ) While the polyethylene chip is introduced into the extruder 100, a fluorine-based polymer is introduced into the extruder 100 through a side feeder, and thereafter there is a method of melting them together. By adding a fluorine-based polymer to the polyethylene, it is possible to further suppress the occurrence of trimming during the spinning process and the multi-stage stretching process, thereby further improving the productivity. The fluorine-based polymer added to polyethylene may be, for example, a tetrafluoroethylene copolymer. The fluorine-based polymer may be added to the polyethylene in an amount such that the content of fluorine in the final produced yarn is 50 to 2500 ppm.

After the polyethylene having the above-described properties is introduced into the extruder 100 and melted, the melted polyethylene is transported through the detention 100 by a screw (not shown) in the extruder 100, and the detention Extruded through a plurality of holes formed in (200). The number of holes in the detention 200 may be determined according to the DPF and total fineness of the yarn to be manufactured. For example, when manufacturing a yarn having a total fineness of 75 denier, the detention 200 may have 20 to 75 holes, and when manufacturing a yarn having a total fineness of 450 denier, the detention 200 is It may have 90 to 450 holes, preferably 100 to 400 holes.

The melting process in the extruder 100 and the extrusion process through the spinneret 200 are preferably performed at 150 to 315 ° C, preferably 250 to 315 ° C, more preferably 265 to 310 ° C. That is, it is preferable that the extruder 100 and the detention 200 are maintained at 150 to 315 ° C, preferably 250 to 315 ° C, more preferably 265 to 310 ° C.

When the spinning temperature is less than 150 ° C, spinning may be difficult because uniform melting of polyethylene is not achieved due to the low spinning temperature. On the other hand, when the spinning temperature exceeds 315 ° C, thermal decomposition of polyethylene may be caused, so that the desired strength may not be exhibited.

The ratio L / D of the hole length D to the hole diameter D of the detention 200 may be 3 to 40. If the L / D is less than 3, die swell occurs during melt extrusion and the elasticity of the polyethylene becomes difficult to control, resulting in poor radioactivity, and when the L / D exceeds 40, it passes through the detention 200 A discharge non-uniformity phenomenon may occur due to the pressure drop along with the trimming by the necking phenomenon of the molten polyethylene.

As the melted polyethylene is discharged from the holes of the custody 200, the solidification of the polyethylene starts due to the difference between the spinning temperature and the room temperature, thereby forming the filaments 11 in a semi-solidified state. In this specification, not only the filament in a semi-solidified state, but also the completely solidified filament is collectively referred to as a "filament."

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

The cooling of the filaments 11 in the cooling unit 300 is preferably performed to be cooled to 15 to 40 ° C. using a cooling wind of 0.2 to 1 m / sec wind speed. When the cooling temperature is less than 15 ° C, elongation may be insufficient due to overcooling, and thus trimming may occur in the stretching process. When the cooling temperature exceeds 40 ° C, fineness deviation between the filaments 11 increases due to uneven solidification, and in the stretching process Trimming may occur.

Subsequently, the cooled and fully solidified filaments 11 are focused with a concentrator 400 to form a multifilament 10.

As illustrated in Figure 1, the method of the present invention, before forming the multi-filament (10), using an oil roller (OR) or oil jet (oil jet) emulsion to the cooled filaments (11) It may further include the step of giving. The emulsion application step may be performed through a MO (Metered Oiling) method.

Alternatively, the step of forming the multifilament 10 through the concentrator 400 and the step of imparting emulsion may be simultaneously performed.

As illustrated in FIG. 1, the polyethylene yarn of the present invention may be manufactured through a direct spin stretching (DSD) process. That is, the multi-filament 10 is directly transferred to the multi-stage stretching unit 500 including a plurality of Godet roller portions GR1 ... GRn, and multi-stage stretching at a total stretching ratio of 2.5 to 8.5, preferably 3.5 to 7.5. After the winder 600 may be wound.

Alternatively, the polyethylene yarn of the present invention may be produced by winding the multifilament 10 as an unstretched yarn and then stretching the unstretched yarn. That is, the polyethylene yarn of the present invention may be produced through a two-step process of stretching the unstretched yarn once the unstretched yarn is prepared by melt spinning polyethylene.

If the total draw ratio applied in the stretching process is less than 3.5, especially less than 2.5, (i) the polyethylene yarn finally obtained cannot have a crystallinity of 60% or more, and the fabric made of the yarn cannot provide a sufficient cooling feeling to the user, (ii) Since the polyethylene yarn cannot have a strength exceeding 4 g / d, a tensile modulus of 15 g / d or more, and a breaking elongation of 55% or less, there is a high risk of causing lint on the fabric made of the yarn. .

On the other hand, when the total elongation ratio exceeds 7.5, especially when it exceeds 8.5, the polyethylene yarn finally obtained cannot have a strength of 6 g / d or less, a tensile modulus of 80 g / d or less, and a breaking elongation of 14% or more. Not only is the weavability of the fabric poor, but the fabric produced using the fabric is too stiff, and the user feels uncomfortable.

When the linear speed of the first Godet roller portion GR1 for determining the spinning speed of the melt spinning of the present invention is determined, the total stretching ratio of 2.5 to 8.5, preferably 3.5 to 7.5 in the multi-stage stretching unit 500 is multi To be applied to the filament 10, the linear speed of the remaining Godet roller portions is appropriately determined.

According to an embodiment of the present invention, the polyethylene through the multi-stage stretching unit 500 by appropriately setting the temperature of the Godet rollers (GR1 ... GRn) of the multi-stage stretching unit 500 in the range of 40 to 140 ℃ Heat-setting of the yarn can be performed. For example, the temperature of the first Godet roller part GR1 may be 40 to 80 ° C, and the temperature of the last Godet roller part GRn may be 110 to 140 ° C. The temperature of each of the remaining Godet roller portions except for the first and last Godet roller portions GR1 and GRn may be set equal to or higher than the temperature of the Godet roller portion immediately preceding it. The temperature of the last Godet roller portion GRn may be set equal to or higher than the temperature of the Godet roller portion immediately preceding, but may be set slightly lower than that.

The 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 multi-filament 10 is wound around the winder 600, thereby providing a polyethylene yarn for cold-sensitive fabric of the present invention. Is completed.

Hereinafter, the present invention will be described in detail through specific examples. However, the following examples are only to aid the understanding of the present invention, and the scope of the present invention should not be limited thereby.

* Production of polyethylene yarn

Example  One

A polyethylene yarn comprising 200 filaments and having a total fineness of 400 denier was prepared using the apparatus illustrated in FIG. 1. Specifically, a polyethylene chip having a density of 0.961 g / cm ³ , a weight average molecular weight (Mw) of 87,660 g / mol, a polydispersity index (PDI) of 6.4, and a melt index (MI at 190 ° C) of 11.9 g / 10min. Was injected into the extruder 100 and melted. The molten polyethylene was extruded through a custody 200 having 200 holes. The ratio of the hole length (L) to the hole diameter (D) of the detention 200 was L / D of 6. The detention temperature was 265 ° C.

The filaments 11 formed while being discharged from the custody 200 were finally cooled to 30 ° C. by a cooling wind of 0.45 m / sec in the cooling unit 300, and the multifilament 10 by the concentrator 400 Concentrated to and moved to the multi-stage stretching unit 500.

The multi-stage stretching portion 500 is composed of a total of five stages of the Godet roller portion, the temperature of the Godet roller portion is set to 70 to 115 ° C, the temperature of the Godet roller portion at the rear end is equal to the temperature of the Godet roller portion immediately before Or higher.

After the multi-filament 10 was stretched by the multi-stage stretching unit 500 at a total stretching ratio of 7.5, it was wound on a winder 600 to obtain a polyethylene yarn.

Example  2

Polyethylene chips with a density of 0.958 g / cm ³ , a weight average molecular weight (Mw) of 98,290 g / mol, a polydispersity index (PDI) of 8.4, and a melt index (MI at 190 ° C.) of 6.1 g / 10 min were used. A polyethylene yarn was obtained in the same manner as in Example 1, except that the detention temperature was 275 ° C.

Example  3

Polyethylene chips with a density of 0.948 g / cm ³ , a weight average molecular weight (Mw) of 78,620 g / mol, a polydispersity index (PDI) of 8.2, and a melt index of 15.5 g / 10min (MI at 190 ° C.) were used. , Detention temperature was 255 ℃, except that the total draw ratio was 6.8 polyethylene yarn was obtained in the same manner as in Example 1.

Comparative example  One

Polyethylene chips with a density of 0.962 g / cm ³ , a weight average molecular weight (Mw) of 98,550 g / mol, a polydispersity index (PDI) of 4.9, and a melt index (MI at 190 ° C) of 6.1 g / 10min were used. A polyethylene yarn was obtained in the same manner as in Example 1, except that the detention temperature was 285 ° C.

Comparative example  2

Polyethylene chips with a density of 0.961 g / cm ³ , a weight average molecular weight (Mw) of 98,230 g / mol, a polydispersity index (PDI) of 7.0, and a melt index (MI at 190 ° C) of 2.9 g / 10min were used. , Detention temperature was 290 ℃, the total drawing ratio was 8.6, except that the polyethylene yarn was obtained in the same manner as in Example 1.

Comparative example  3

Polyethylene chips with a density of 0.961 g / cm ³ , a weight average molecular weight (Mw) of 180,550 g / mol, a polydispersity index (PDI) of 6.4, and a melt index of 0.6 g / 10min (MI at 190 ° C.) were used. , Detention temperature was 300 ℃, was stretched at a total draw ratio of 14 through a multi-stage stretching section 500 consisting of a total of 8 Godet roller parts, the temperature of the Godet roller parts was set to 75 to 125 ℃ A polyethylene yarn was obtained in the same manner as in Example 1.

The stiffness properties, toughness, tensile strength, tensile modulus, elongation at break, crystallinity, and polydispersity index (PDI) of the polyethylene yarns prepared by Examples 1-3 and Comparative Examples 1-3, respectively, were measured as follows, Measurement results are shown in Table 1 below.

* Elongation properties of polyethylene yarn, tensile strength, tensile Modulus , And Rupture , And toughness

Elongation curves (x-axis: elongation, y-axis: strength) of polyethylene yarn at room temperature were obtained according to ASTM D885 method using an all-purpose tensile tester from Instron Engineering Corp (Canton, Mass) (sample length: 250 mm) , Tensile speed: 300 mm / min, initial load: 0.05 g / d), from which the polyethylene yarn "elongation at strength of 1 g / d", "elongation at strength of 3 g / d "," The difference between elongation at 4 g / d strength and elongation at maximum strength ", tensile strength, tensile modulus, and elongation at break were respectively obtained. In addition, the toughness of the polyethylene yarn was obtained by calculating the area between the stiffness curve (x-axis: elongation, y-axis: strength) and the x-axis through integration.

* Crystallinity of polyethylene yarn

The crystallinity of the polystyrene yarn was measured using an XRD instrument (X-ray Diffractometer) (manufacturer: PANalytical, model name: EMPYREAN). Specifically, a sample having a length of 2.5 cm was prepared by cutting a polyethylene yarn, and after fixing the sample to a sample holder, measurement was performed under the following conditions.

-X-ray Source: Cu-Kα radiation

-Power: 45 KV x 25 mA

-Mode: Continuous scan mode

-Scanning angle range: 10 ~ 40 °

-Scan speed: 0.1 ° / sec

* Polyethylene yarn Polydispersity Index ( PDI )

After the polyethylene yarn was completely dissolved in the following solvent, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyethylene yarn were respectively determined by gel permeation chromatography (GPC), and then the number average molecular weight (Mn) The polydispersity index (PDI) of the polyethylene yarn was determined by calculating the ratio (Mw / Mn) of the weight average molecular weight (Mw) to).

-Analyzer: PL-GPC 220 system

-Column: 2 × PLGEL MIXED-B (7.5 × 300mm)

-Column temperature: 160 ℃

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

-Dissolution conditions: 160 ℃, 1-4 hours, after dissolving, measure the solution that passed through the glass filter (0.7㎛)

-Injector, Detector temperature: 160 ℃

-Detector: RI Detector- Flow rate: 1.0 ml / min

-Injection volume: 200 μl

-Standard sample: Polystyrene

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 PE Density (g / cm ³ ) 0.961 0.958 0.948 0.962 0.961 0.961 Mw (g / mol) 87,660 98,290 78,620 98,550 98,230 180,550 PDI 6.4 8.4 8.2 4.9 7.0 6.4 MI (g / 10min) 11.9 6.1 15.5 6.1 2.9 0.6 Detention temperature (℃) 265 275 255 285 290 300 Total stretch ratio 7.5 7.5 6.8 7.5 8.6 14 PE yarn Elongation (%) @ 1 g / d 1.75 1.92 1.45 0.95 0.82 0.45 Elongation (%) @ 3 g / d 7.1 8.3 6.2 4.4 4.8 1.52 | Elongation (%) @ 4 g / d-Elongation (%) @ Maximum Strength | 15 12 9.5 7.0 5.2 4.7 Toughness (J / m ³ ) 86 92 65 52 50 72 Tensile strength (g / d) 4.6 5.3 4.3 6.5 7.2 17.3 Tensile modulus (g / d) 49.6 56.3 42.6 63.4 68.4 485 Elongation at break (%) 25 22 28 13.5 11.8 6.6 Crystallinity (%) 72 74 71 73 74 80 PDI 5.6 6.8 6.3 3.3 4.9 4.4

* Cold feeling  Fabric Manufacturing

Example  4

Fabrics having a warp density of 30 ea / inch and a weft density of 30 ea / inch were obtained by performing plain weaving using the polyethylene yarn of Example 1 as warp and weft.

Example  5

Fabrics were obtained in the same manner as in Example 4, except that the polyethylene yarn of Example 2 was used.

Example  6

Fabrics were obtained in the same manner as in Example 4, except that the polyethylene yarn of Example 3 was used.

Comparative example  4

Fabrics were obtained in the same manner as in Example 4, except that the polyethylene yarn of Comparative Example 1 was used.

Comparative example  5

Fabrics were obtained in the same manner as in Example 4, except that the polyethylene yarn of Comparative Example 2 was used.

Comparative example  6

Fabrics were obtained in the same manner as in Example 4, except that the polyethylene yarn of Comparative Example 3 was used.

The contact cooling feeling (Q _max ), thermal conductivity (thickness direction), heat transfer coefficient (thickness direction), peeling resistance, abrasion resistance, and ductility of the cold-sensitized fabrics prepared by Examples 4-6 and Comparative Examples 4-6, respectively. Each was measured as follows, and the measurement results are shown in Table 2 below.

* Of fabric Contact cooling ( Q _max )

After preparing a fabric sample having a size of 20 cm × 20 cm, it was left for 24 hours under the conditions of 20 ± 2 ° C. and 65 ± 2% RH. Subsequently, the contact cooling (Q _max ) of the fabric was measured using a KES-F7 THERMO LABO II (Kato Tech Co., LTD.) Apparatus at a temperature of 20 ± 2 ° C. and a test environment of 65 ± 2% RH. Specifically, as illustrated in FIG. 2, the fabric sample 23 is placed on a base plate (also referred to as 'Water-Box') 21 maintained at 20 ° C, and T- heated to 30 ° C. Box 22a (contact area: 3 cm × 3 cm) was placed on the fabric sample 23 for only 1 second. That is, the other surface of the fabric sample 23, one surface of which is in contact with the base plate 21, was instantaneously 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 / cm ² . The Q _max value displayed on the monitor (not shown) connected to the device was then recorded. This test was repeated 10 times, and the arithmetic mean of the Q _max value was calculated.

* Heat conductivity and heat transfer coefficient of fabric

After preparing a fabric sample having a size of 20 cm × 20 cm, it was left for 24 hours under the conditions of 20 ± 2 ° C. and 65 ± 2% RH. Subsequently, the thermal conductivity and heat transfer coefficient of the fabric were obtained using a KES-F7 THERMO LABO II (Kato Tech Co., LTD.) Apparatus at a temperature of 20 ± 2 ° C. and a test environment of 65 ± 2% RH. Specifically, as illustrated in FIG. 3, the fabric sample 23 is placed on the base plate 21 maintained at 20 ° C., and the BT-Box 22b heated to 30 ° C. (contact area: 5 cm × 5 cm) was placed on the fabric sample 23 for 1 minute. Heat was continuously supplied to the BT-Box 22b so that the temperature could be maintained at 30 ° C while the BT-Box 22b was in contact with the fabric sample 23. The amount of heat supplied to maintain the temperature of the BT-Box 22b (ie, heat flow loss) was displayed on a monitor (not shown) connected to the device. This test was repeated 5 times, and the arithmetic mean of heat flow loss was calculated. Subsequently, 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 · ℃), D is the thickness (cm) of the fabric sample 23, A is the contact area (= 25 cm ² ) of the BT-Box 22b, ΔT Is the temperature difference (= 10 ° C) on both sides of the fabric sample 23, W is the heat flow loss (Watt), and k is the heat transfer coefficient (W / cm ² · ° C).

* Stiffness of fabrics

 The ductility of the fabric was measured by the circular bend method using a ductility measurement device according to ASTM D 4032. The lower the stiffness (kgf), the softer the fabric.

* Fabrics Peeling Resistance

Using a Martindale tester, the peeling resistance of the fabric was measured according to ASTM D 4970-07 (friction motion number: 200 times in total). The peeling resistance class criteria are as follows.

-Level 1: Peeling is very severe

-Level 2: Peeling

-Level 3: Middle filling

-Level 4: Some peeling

-Level 5: No peeling at all

* Wear resistance of fabrics

Using a Martindale tester, the abrasion resistance of the fabric was measured according to the Martindale method specified in KS K ISO 12947-2: 2014. Specifically, the number of cycles (cycles) from the fabric until two yarns were cut was measured.

Example 4 Example 5 Example 6 Comparative Example 4 Comparative Example 5 Comparative Example 6 Q _max (W / cm ² ) 0.159 0.167 0.149 0.166 0.167 0.168 Thermal conductivity (W / cm · ℃) 0.00043 0.00048 0.00039 0.00053 0.00058 0.00062 Heat transfer coefficient (W / cm ² · ℃) 0.0126 0.0142 0.0123 0.00147 0.00149 0.00153 Lecture strength (kgf) 0.45 0.52 0.43 0.65 0.72 0.95 Peeling resistance (grade) 4 4 4 3 3 4 Wear resistance (cycles) 6,530 7,560 5,280 4,510 4,730 18,540

100: Extruder 200: Detention
300: cooling zone (quenching zone) 400: focusing section
500: multistage stretching unit 600: winder

Claims (10)

In the polyethylene yarn,
In the elongation curve of the polyethylene yarn obtained by measuring at room temperature, (i) elongation at a strength of 1 g / d is 0.5 to 3%, and (ii) elongation at a strength of 3 g / d is 5.5 to 10%. , (iii) The difference between elongation at 4 g / d intensity and elongation at maximum intensity is 5.5 to 25%,
The polyethylene yarn has a toughness of 55 to 120 J / m ³ at room temperature,
Polyethylene yarn. According to claim 1,
The polyethylene yarn has a tensile strength of more than 4 g / d and 6 g / d or less, a tensile modulus of 15 to 80 g / d, an elongation to break of 14 to 55%, and a crystallinity of 60 to 85%,
Polyethylene yarn. According to claim 1,
The polyethylene yarn has a weight average molecular weight (Mw) of 50,000 to 99,000 g / mol and a polydispersity index (PDI) of 5 to 9,
Polyethylene yarn. According to claim 1,
The polyethylene yarn has a total fineness of 75 to 450 denier,
The polyethylene yarn comprises a plurality of filaments each having a fineness of 1 to 5 denier (denier),
Polyethylene yarn. According to claim 1,
The polyethylene yarn has a circular cross section,
Polyethylene yarn. A cold-sensitive fabric formed of the polyethylene yarn of any one of claims 1 to 5,
The cold-sensitive fabric at 20 ° C. has a thickness direction thermal conductivity of 0.0001 W / cm · ° C. or more, a thickness direction heat transfer coefficient of 0.001 W / cm ² · ° C. or more, and a contact cooling feeling (Q _max ) of 0.1 W / cm ² or more,
Cool fabric. The method of claim 6,
Peeling resistance of the cold-sensitive fabric measured according to ASTM D 4970-07 is 4 or higher,
The wear resistance of the cold-sensitive fabric measured according to the Martindale method defined in KS K ISO 12947-2: 2014 is 5000 cycles or more,
Cool fabric. The method of claim 6,
The surface density of the cold-sensitive fabric is 75 to 800 g / m ²
Cool fabric. Density from 0.941 to 0.965 g / cm ³ , weight average molecular weight (Mw) from 50,000 to 99,000 g / mol, polydispersity index (PDI) from 5.5 to 9, and melt index from 6 to 21 g / 10min (Melt Index: MI ) (At 190 ° C.) melting the polyethylene;
Extruding the molten polyethylene through a custody having a plurality of holes;
Cooling the plurality of filaments formed when the molten polyethylene is discharged from the holes of the custody; And
Stretching the multifilament made of the cooled filaments
Containing,
Method of manufacturing polyethylene yarn. The method of claim 9,
The stretching step is performed at a stretching ratio of 2.5 to 8.5,
Method of manufacturing polyethylene yarn.

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