KR101456919B1 - Preparing method of filament yarn - Google Patents

Abstract

The present invention relates to a method for manufacturing filament yarn. More specifically, the method includes the steps of: manufacturing a molded body in the shape of a sheet from a gel solution including thermoplastic polymer and a solvent; removing the solvent by heating the molded body in the shape of a sheet; manufacturing a film with thickness of 2-500 μm by firstly elongating the molded body in the shape of a sheet from which the solvent is removed; and manufacturing monofilaments of 30-10,000 deniers by secondly elongating the film while the film is heated at the temperature of glass transition or higher. Therefore, according to the method, monofilaments can be manufactured to have deniers up to 1,000 regardless of denier even when a polymer with ultra-high molecular weight is used.

Description

[0001] Preparing method of filament yarn [0002]

The present invention relates to a method for producing a yarn.

Ultra high molecular weight polyethylene fibers have a mechanical performance comparable to other high performance fibers. Low density, high nose and inelasticity are the greatest, and these performances are beyond metal. More importantly, it has good energy absorption characteristics, is particularly suitable for absorbing impact energy of low speed, and has excellent bulletproof performance and is used as an ideal bulletproof material. At the same time, it has been widely used for security and military purposes, and it is currently being used as a defense material for the best cable material and advanced technology.

Ultra high molecular weight polyethylene fibers are light and soft and have excellent properties such as high strength, high elasticity, anti-ultraviolet ray, impact resistance and seawater corrosion resistance, and are used in various fields such as cut-resistant gloves, In addition, ultrahigh molecular weight polyethylene fibers are expected to be widely used in civil engineering applications as anti-impact, vibration damping materials and high performance lightweight composites.

Examples of the method for producing the polymer fiber include dry spinning, wet spinning, melt spinning and gel spinning. In the case of the above ultra-high molecular weight polyethylene, since it is not easy to dissolve in a solvent, Is difficult to manufacture and is difficult to be melted, so that it is also difficult to produce by melt spinning. Therefore, it is produced by the gel spinning method.

The gel-spinning method is a process in which a gel solution formed by mixing polymer polyethylene with a spinning solvent is melt-extruded to form filaments, and then the solvent is extracted and stretched. As a result, the spinning solvent is not sufficiently extracted, If it is contained in a large amount, the physical properties such as strength may be deteriorated, and sufficient solvent extraction process should be performed. However, if the filament is thick, it takes a long time to extract the solvent and the productivity is remarkably decreased. Therefore, this method has a limitation in the thickness of the filament that can be produced.

Korean Patent Publication No. 2007-101836 discloses a stretched gel-spun polyethylene yarn and a stretching method.

Korea Patent Publication No. 2007-101836

It is an object of the present invention to provide a method of producing a yarn capable of producing monofilaments ranging from three deniers to several thousand deniers without solvent extraction even when an ultrahigh molecular weight polymer is used as a raw material.

1. A process for producing a sheet-shaped molded article, comprising: preparing a gel solution containing a thermoplastic polymer and a solvent;

Heating the sheet-shaped formed body or dipping the sheet-shaped molded body in an extracting medium to remove the solvent;

A step of firstly stretching the sheet-shaped formed article from which the solvent has been removed to produce a film having a thickness of 2 to 500 占 퐉; And

Preparing a monofilament of 30 denier to 10,000 denier by the second stretching while applying heat above the glass transition temperature of the polymer to the film;

≪ / RTI >

2. The method of producing a yarn according to 1 above, wherein the first stretching is biaxial stretching, wherein the stretching ratio is four times or more in both the longitudinal and transverse directions, and the total stretching ratio is 25 to 60 times.

3. The method of producing a yarn according to 1 above, wherein the film has a cross-sectional area in a direction perpendicular to the second stretching direction of 0.001 to 0.45 cm ² .

4. The method of producing a yarn as in 1 above, wherein said second stretching is performed at a total stretching ratio of 1.5 to 12 times.

5. The method of producing a yarn according to 4 above, wherein said second stretching is two-step stretching performed at a stretching ratio of 1.2 to 3.5 times.

6. The method according to 1 above, wherein the thermoplastic polymer is selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol and aramid.

7. The composition of claim 1 wherein said solvent is selected from the group consisting of nonane, decane, decalin, p-xylene, undecane, dodecane, liquid paraffin, dibutyl phthalate, dioctyl phthalate, stearyl alcohol, ceryl alcohol and paraffin oil At least one selected from the group consisting of:

8. In the first place, the extracted tying pentane, hexane, heptane, methylene chloride, carbon tetrachloride, diethyl ether, dioxane, methyl ethyl ketone, trifluoromethyl _{ethane, C 6 F 14, C 7} F 16, C 5 H Wherein at least one selected from the group consisting of ₃ F ₇ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , C ₄ F ₉ OCF ₃ and C ₄ F ₉ OC ₂ F ₅ is used.

9. The production method according to item 1 above, wherein the solvent-removed sheet-shaped molded article has a solvent content of less than 1,000 ppm of the total weight of the sheet-shaped molded article.

10. The method according to 1 above, wherein the monofilament is from 1,000 denier to 10,000 denier.

11. The method of producing a yarn according to 1 above, wherein the thickness of the produced film is 5 to 500 mu m.

12. The method of producing a yarn according to 1 above, wherein the thermoplastic polymer has a weight average molecular weight of 500,000 or more.

13. The method of producing a yarn according to 1 above, wherein the thermoplastic polymer is polyethylene having an Intrinsic Viscosity (IV) of 5 dl / g or more.

14. The method of claim 1, wherein the second stretching is performed by rapidly rotating a stretching roller located behind the heat chamber in front of a film transport roller located in front of a heat chamber that applies heat above a glass transition temperature of the polymer, ≪ / RTI >

The present invention can produce monofilaments ranging from three deniers to several thousand deniers without solvent extraction even when ultra high molecular weight polymer is used as a raw material.

The present invention relates to a method for producing a sheet-shaped molded article, comprising the steps of: preparing a gel solution containing a thermoplastic polymer and a solvent; Applying heat to the sheet-shaped formed body to remove the solvent; A step of firstly stretching the sheet-shaped formed article from which the solvent has been removed to produce a film having a thickness of 2 to 500 占 퐉; And a step of preparing a monofilament having a denier of from 30 denier to 10,000 denier by applying a second stretching process to the film while heating the polymer at a temperature higher than the glass transition temperature of the polymer. Thus, even when a polymer having an ultra-high molecular weight is used as a raw material, The present invention relates to a method of producing a yarn, which can produce a monofilament without limitation of denier up to denier.

In this specification, monofilament refers to a long fiber yarn obtained from a synthetic fiber, and includes not only a circular or elliptical cross section but also a polygonal or flattened form.

And, the yarn is a multifilament in which such a monofilament itself or a plurality of monofilaments is formed by being joined or twisted.

In the case of the conventional monofilament prepared by gel-spinning, since the spinning solvent must be extracted from the filament, there is a limitation on the thickness that can be produced. However, in the manufacturing method of the present invention, the polymer film prepared from the gel solution, Since the monofilaments are formed, monofilaments can be produced without any solvent extraction at the time of formation of the monofilaments and without limitation in thickness.

Hereinafter, the present invention will be described in more detail with reference to an embodiment of the present invention.

First, a gel solution containing a thermoplastic polymer and a solvent is prepared as a sheet-shaped molded article.

The polymer is thermoplastic and is not particularly limited as long as it can form monofilaments by heating and stretching after the production of the film. Examples of the polymer include polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol, .

In the case of ultrahigh molecular weight polymers capable of forming filament yarns only by the gel spinning method, there are limitations on the thickness of the monofilament that can be produced by conventional gel spinning processes (about 200 to 300 denier) Monofilaments ranging from denier to several thousand denier can be produced. Therefore, when the polymer is an ultra-high-molecular-weight polymer that can be produced only by a gel spinning method, the advantages of the present invention can be maximized. For example, the weight average molecular weight may be 500,000 or more. For example, the weight average molecular weight may be 500,000 to 8,000,000. Within this range, it may be 500,000 to 8,000,000, 1,000,000 to 8,000,000, or the like, but is not limited thereto.

However, the method for producing a yarn of the present invention can be similarly applied to a raw material other than the ultrahigh molecular weight polymer. Therefore, the molecular weight of the polymer to be applied is not particularly limited, and for example, a weight average molecular weight of 300,000 or more, 8,000,000.

Preferably an intrinsic viscosity (IV) of 5 dl / g or more, more preferably 8 dl / g to 45 dl / g, measured by decalin at 135 ° C. Since such a polyethylene can be produced only by a gel-spinning method, a thick monofilament can not be obtained by a conventional method, and thus the advantages of the present invention can be exerted to the polyethylene as much as possible.

The solvent may be a solvent used for ordinary gel-spinning, for example, nonane, decane, decalin, p-xylene, undecane, dodecane, liquid paraffin, dibutyl phthalate, dioctyl phthalate, stearyl alcohol, Ceryl alcohol, paraffin oil, and the like. These may be used alone or in combination of two or more.

The method for producing the sheet-shaped formed body is not particularly limited and may be a method known in the art. For example, the gel solution may be formed by extruding with a die-attached extruder, casting or the like.

The sheet-like formed body may be formed into a sheet-like body by extrusion, casting or the like as an intermediate of a film to be described later, and then further subjected to a cooling step as required.

The cooling temperature is not particularly limited, and may be, for example, 0 to 25 ° C.

The cooling method is not particularly limited, and any conventional method can be used in the art. For example, the cooling method may be carried out by bringing a cooling medium such as cooling air, cooling water, etc. into contact with the cooling roller or the like.

Thereafter, heat is applied to the sheet-shaped formed body to remove the solvent.

Removal of the solvent may be removed by applying heat at elevated temperature to evaporate or volatilize the solvent, or by immersing it in a solvent to dissolve or transfer the solvent to the solvent.

The heating temperature in the case of evaporating or volatilizing the solvent is not particularly limited and may be, for example, 50 to 150 ° C.

The extraction solvent is not particularly limited as long as it can dissolve or transfer at least a part of the solvent, for example, saturated hydrocarbons such as pentane, hexane, heptane and the like; Chlorinated hydrocarbons such as methylene chloride, carbon tetrachloride and the like; Ethers such as diethyl ether, dioxane and the like; Ketones such as methyl ethyl ketone and the like; Trifluoro ethane, C ₆ F _14, carbon at a linear fluoroalkyl such as C ₇ F _16; Cyclic hydrofluorocarbons such as C ₅ H ₃ F ₇ and the like; Hydrofluoroethers such as C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ and the like; And a _{C 4 F 9 OCF 3, C} 4 F 9 OC 2 F 5 1 -volatile solvent such as ether or more species such as a perfluoroalkyl.

The temperature of the extracting medium is not particularly limited, and may be, for example, 25 to 80 캜.

Although the amount of the solvent to be removed is not particularly limited, in general, the higher the amount of the solvent is removed from the sheet-shaped molding, the higher the quality of the film is obtained. In one embodiment, the solvent may be removed until the amount of solvent remaining in the sheet-shaped article is less than 1,000 ppm, preferably less than 500 ppm, and more preferably less than 200 ppm, based on the weight of the sheet-shaped article.

Next, the sheet-shaped formed article from which the solvent is removed is first stretched to produce a film.

The stretching is not particularly limited as long as the polymer film can be uniformly stretched in the progress direction (MD direction) by applying heat to the polymer film, and can be carried out by a method commonly used in the art. For example, any stretching method such as stretching stretching in which longitudinal stretching in the longitudinal direction is carried out by simultaneous stretching of a tenter type or a roll and secondary stretching in the transverse direction is performed by a tenter can be used.

The stretching ratio is preferably at least 4 times in the longitudinal direction and in the transverse direction, and the total stretching ratio is preferably 25 to 60 times. When the stretching ratio in one direction is less than 4 times, the orientation in one direction is not sufficient and the balance of physical properties between the longitudinal direction and the transverse direction may be lowered. If the total draw ratio is less than 25 times, it may be difficult to produce monofilaments having a sufficient strength by the second elongation which will be described later. If it exceeds 60 times, there is a high possibility that breakage occurs during stretching, and the shrinkage ratio of the film may be increased.

The film produced by stretching has a thickness of 2 탆 to 500 탆. When the thickness is within the above range, a monofilament having a thickness of 30 to 10,000 denier can be produced by a second stretching which will be described later. In terms of producing a monofilament having a thickness of 1,000 denier or more, the thickness may be 5 탆 to 500 탆.

According to another embodiment of the present invention, the first stretching may be performed before, during, or after the removal of the solvent, or may be carried out in various stages. The thickness, width, material, molecular weight, But may be performed in two or more steps in accordance with the denier of the filament. In addition, drying, cooling, and other conventional processes in the art can be further included.

According to an embodiment of the present invention, the film is first stretched so that the cross-sectional area in a direction perpendicular to the second stretching direction becomes 0.001 to 0.45 cm ² . In such a case, monofilaments having a fineness of 30 to 10,000 denier, which will be described later, can be produced without weakening the strength due to lack of elongation through the second elongation to be described later, and without breaking the polymer molecular chains due to stretching.

Thereafter, a monofilament of 30 denier to 10,000 denier is prepared by second stretching the film while applying heat at a temperature higher than the glass transition temperature of the polymer.

The second stretching is not particularly limited as long as the polymer film can be uniformly stretched in the progress direction (MD direction) by applying heat to the polymer film, and can be performed by a method commonly used in the art. For example, by rotating the stretching roller located behind the heat chamber faster than the film transport roller located in front of the heat chamber that applies heat above the glass transition temperature of the polymer. When this method is performed, the stretching can be performed uniformly in the film traveling direction uniformly without necking of the polymer.

The stretching is carried out by applying heat above the glass transition temperature to the polymer film. Preferably, it can be carried out by applying heat at a temperature higher than the glass transition temperature and lower than the melting point. When the heat treatment temperature is lower than the glass transition temperature, stretching is difficult to be performed uniformly. If the heat treatment temperature is higher than the melting point, orientation of the polymer chains is difficult and stretching of the film itself may not be easy. For example, in the case of polyethylene having an Intrinsic Viscosity (IV) of 5 dl / g or more, heat of 80 to 140 占 폚 can be applied.

Heating means may be positioned within the thermal chamber to apply heat to the film passing through the thermal chamber. The heating means is not particularly limited as long as it can uniformly apply heat to the film passing through the heat chamber, and can be, for example, hot water, hot air, hot plate, hot wire, heating roll, infrared ray and the like.

The second stretching ratio is not particularly limited and may be appropriately selected according to the thickness, width, denier, strength, elastic modulus, etc. of the filament yarn to be produced. For example, the stretching ratio is 1.5 to 12 times, preferably 3.5 to 10 It can be boats. If the stretching ratio is less than 1.5 times, it is difficult to produce high-strength monofilaments. If the stretching ratio is more than 12 times, the molecular chains of the polymer may be broken by the stretching tension, and the strength may be similarly lowered.

From the standpoint of producing a monofilament having a higher strength, the second stretching can be preferably carried out in a plurality of steps. For example, in the case of performing in two steps, within the range of satisfying the stretching ratio of the second stretching, the 2-1 stretching is performed at a stretching ratio of 1.2 to 3.5 times and the 2-2 stretching is performed at a stretching ratio of 1.2 to 3.5 times . In such a case, the strength improvement effect can be maximized.

For example, when stretching is performed through the above-described conveying roller and stretching roller, if the rotation speed of the stretching roller is made equal to the rotation speed of the conveying roller, a method of controlling the stretching ratio at a stretching ratio of 1 times , And at a speed of 20 times, the stretching is performed at a stretching ratio of 20 times.

The thickness of the monofilament prepared by the above method is not particularly limited and may be, for example, from 30 denier to 10,000 denier, and may be in the range of 1,000 to 10,000 denier, for example, depending on the type of polymer, molecular weight, thickness, It can be used only for the production of monofilaments. If the thickness is less than 30 deniers, the filament is too thin to be handled easily, and the filament is frequently broken at the time of winding the produced filament.

The yarn according to the present invention can be used as yarn in various fields such as body armor, safety gloves, medical use, various ropes, helmet, and ski board.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Example  1-5 and Comparative Example  One

(1) Production of film

Molecular weight polyethylene having a weight average molecular weight (Mw) of 2.0 占⁰⁶ and a molecular weight distribution (Mw / Mn) of 8 and a melting point (Tm) of 135 占 폚, tetrakis 3,5-di-tert-4-hydroxyphenyl) -propionate] methane were mixed.

50 parts by weight of paraffin oil was supplied to 50 parts by weight of the obtained mixture and mixed by rotating to prepare a gel solution.

The gel solution was supplied to a T die from an extruder to prepare a sheet-shaped formed body, and the sheet-shaped formed body thus prepared was immersed in methylene chloride heated to 30 DEG C for 3 minutes to remove the paraffin oil.

The sheet-shaped formed article from which the paraffin oil had been removed was moved by a roller, and heat was applied at 100 DEG C, and the film was first stretched in the machine direction and the transverse direction.

(2) Monofilament  Produce

A monofilament was prepared by rapidly rotating the stretching roller located at the rear of the heat chamber in the second stretching than the film feeding roller located in front of the heat chamber for applying heat at 120 캜 while moving the film by the roller.

Examples 1, 4 and 7 performed the second stretching in one step and the remainder in two steps.

division First Drawing Ratio
(ship) Thickness of film (탆) Sectional area in the direction perpendicular to the second stretching direction of the film
(cm ² ) The second stretching ratio
(ship) Fineness of monofilament
(Denier) Stage 1 Step 2 Bell Transverse Example 1 6 6 2 0.002 5.5 50 Example 2 6 6 10 0.019 2 3 600 Example 3 6 6 20 0.026 3.5 2 1,000 Example 4 6 6 50 0.16 5.8 5,000 Example 5 6 6 500 0.4 3.5 1.5 10,000 Example 6 6 6 4 0.001 1.5 3.5 30 Example 7 6 6 4 0.001 4.8 50 Example 8 4 4 4 0.001 4.8 50 Comparative Example 1 6 6 One 0.0008 3 1.5 25

Comparative Example  2

The gel solution of Example 1 was spun, the solvent was removed by the same method, and the solution was stretched 15 times to prepare a monofilament having a fineness of 600 denier.

Comparative Example  3

The gel solution of Example 1 was spun and the solvent was removed in the same manner and then stretched 9 times to prepare a monofilament of 1,000 denier in fineness.

Experimental Example

(1) Residual solvent content measurement

The residual solvent content in the monofilament in the present invention was measured using " gas chromatography " manufactured by Shimadzu Corporation.

First, 10 mg of the monofilament was set in a glass insert of a gas chromatography injection port. Subsequently, the injection port was heated above the boiling point of the solvent, and the solvent generated by heating was introduced into the column with nitrogen purge. Next, the column temperature was set to 40 DEG C, and the solvent was trapped for 5 minutes. Next, the column temperature was raised to 80 DEG C and measurement was started. The residual solvent concentration was obtained from the obtained peak.

(2) Monofilament The tensile strength  Measure

The denier of the filament was measured and the tensile strength of the filament was measured using a universal tensile tester (Instron Model-4202) under the conditions of a grip interval of 300 mm and a speed of 300 mm / min.

division Fineness (denier) of monofilament Residual Solvent Content (ppm) The tensile strength
(g / d) Example 1 50 185 17.5 Example 2 600 290 19.4 Example 3 1,000 320 20.5 Example 4 5,000 765 17.2 Example 5 10,000 950 16.1 Example 6 30 165 18.7 Example 7 50 190 16.5 Example 8 50 360 14.7 Comparative Example 1 25 250 12.1 Comparative Example 2 600 2,750 9.8 Comparative Example 3 1,000 5,300 8.5

Referring to Table 2, the monofilaments prepared by the methods of Examples 1 to 7 had very low residual solvent content of less than 1% even in the case of tanneries having a denier of 1,000 denier or more as well as three-denier monofilaments, The strength was very high.

However, the monofilament produced by the method of Comparative Example 1 was not easy to handle due to a very low fineness, and there was a problem that it was frequently broken at the time of winding.

The monofilaments prepared by the methods of Comparative Examples 2 and 3 had a high fineness but a very high residual solvent content and a very low tensile strength.

Claims (14)

Preparing a gel solution containing a thermoplastic polymer and a solvent as a sheet-shaped molding;
Heating the sheet-shaped formed body or dipping the sheet-shaped molded body in an extracting medium to remove the solvent;
A step of firstly stretching the sheet-shaped formed article from which the solvent has been removed to produce a film having a thickness of 2 to 500 占 퐉; And
Preparing a monofilament of 30 denier to 10,000 denier by the second stretching while applying heat above the glass transition temperature of the polymer to the film;
≪ / RTI >
The method of manufacturing a yarn according to claim 1, wherein the first stretching is biaxial stretching, wherein the stretching ratio is four times or more in the longitudinal direction and the transverse direction, respectively, and the total stretching ratio is 25 to 60 times.
The method according to claim 1, wherein the film has a cross-sectional area in a direction perpendicular to the second stretching direction of 0.001 to 0.45 cm ² .
The method according to claim 1, wherein the second stretching is performed at a total stretching ratio of 1.5 to 12 times.
5. The method according to claim 4, wherein the second stretching is two-step stretching performed at a stretching ratio of 1.2 to 3.5 times.
The method of producing a yarn according to claim 1, wherein the thermoplastic polymer is selected from the group consisting of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol and aramid.
The method of claim 1, wherein the solvent is selected from the group consisting of nonane, decane, decalin, p-xylene, undecane, dodecane, liquid paraffin, dibutyl phthalate, dioctyl phthalate, stearyl alcohol, A method of manufacturing a yarn.
The process according to claim 1, wherein the extractant is selected from the group consisting of pentane, hexane, heptane, methylene chloride, carbon tetrachloride, diethyl ether, dioxane, methyl ethyl ketone, trifluoroethane, C ₆ F ₁₄ , C ₇ F ₁₆ , C ₅ H ₃ F ₇ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , C ₄ F ₉ OCF ₃ and C ₄ F ₉ OC ₂ F ₅ .
The production method according to claim 1, wherein the solvent-removed sheet-shaped molded article has a solvent content of less than 1,000 ppm in the total weight of the sheet-shaped molded article.
The method according to claim 1, wherein the monofilament is from 1,000 denier to 10,000 denier.
The method according to claim 1, wherein the thickness of the produced film is 5 to 500 μm.
The method of producing a yarn according to claim 1, wherein the thermoplastic polymer has a weight average molecular weight of 500,000 or more.
The method according to claim 1, wherein the thermoplastic polymer is polyethylene having an Intrinsic Viscosity (IV) of 5 dl / g or more.
The method of claim 1, wherein the second stretching is performed by rapidly rotating a stretching roller located behind the heat chamber in front of the film transferring roller located in front of the heat chamber applying heat above the glass transition temperature of the polymer. Way.