KR20020081604A - A polyurethane type elastic fiber, and a process of preparing for the same - Google Patents

Abstract

PURPOSE: Provided are polyurethane type elastic fiber which is characterized by having heat resistance, having thermosetting property and having excellent coherence between monofilaments, and a manufacturing method thereof having excellent spinning ability. CONSTITUTION: The polyurethane type elastic fiber is obtained by a process containing the steps of: producing prepolymer in a tubular continuous polymerizing machine; chain-extending and chain-terminating the prepolymer to produce polymer; and then adding additives to the polymer. The tubular continuous polymerizing machine is comprised of a uniform mixing element, a heater, a reactor and a cooler. The prepolymer is obtained by a process containing the steps of: (i) mixing polyol having high molecular weight and excessive diisocyanate in the uniform mixing element without an inner mixing element on condition that shear rate is at least 20sec¬-1; (ii) reacting first the mixture in the heater on condition that shear rate is at least 3sec¬-1; and then (iii) reacting second the first reactant in the reactor on condition that shear rate is at least 0.1sec¬-1.

Description

Polyurethane-based elastic fiber and its manufacturing method {A polyurethane type elastic fiber, and a process of preparing for the same}

The present invention relates to a polyurethane-based elastic fiber and a method of manufacturing the same. More specifically, the present invention relates to a method for producing a polyurethane-based elastic fiber that can increase the stability of the polymer and excellent in the high-speed spinning properties and can significantly reduce the generation of wave yarns. In addition, the present invention relates to a polyurethane-based elastic fiber excellent in heat resistance, heat setting efficiency and bonding strength between the monofilament.

The polyurethane polymer may be prepared by a first stage polymerization method of simultaneously reacting a polyol having a high molecular weight of 1600 to 2000 g / mol, an excess of diisocyanate and a chain extender, which is a diol or a diamine compound, and the high molecular weight polyol Prepolymerization of the excess diisocyanate compound first to prepare the prepolymer in one step, and then to the chain extension and chain stop reaction in two steps by adding a chain extender and a chain stopper, which is a diol or diamine compound. It can also be manufactured by law.

The two-step polymerization method is easier to obtain a more regular structure than the one-step polymerization method, it is easy to control the degree of polymerization because of the low possibility of crosslinking. Most of the polyurethane-based elastic fibers currently produced are manufactured by a two-stage polymerization method.

More specifically, in the two-step polymerization method, the first stage prepolymerization forms a urethane bond by reaction of a high molecular weight diol compound polyol with an excess of diisocyanate, and a preliminary having an isocyanate group at the sock end of the polyol. It is a step to make a polymer.

In general, the molecular weight of the polyol is about 1,800g / mole, the NCO / OH ratio is 1.6 ~ 1.8 polymerization proceeds. The prepolymerization is usually completed in 1 to 2 hours at about 60 ~ 90 ℃ in a bulky state without solvent. The higher the reaction temperature, the faster the reaction rate. If a solvent such as dimethylacetamide (hereinafter referred to as "DMAc") or dimethylformamide (hereinafter referred to as "DMF") is used, the reaction rate increases due to the catalysis of the solvent. The reaction is completed in 10 to 20 minutes at 30 to 60 ° C.

The chain extension reaction, which is a second step, is a reaction that increases the degree of polymerization by reacting a prepolymer with a compound having low molecular weight active hydrogen such as ethylenediamine, propylenediamine, 1,4-butanediol, and the like as a chain extender.

When reacted with diamine (urea) bonds are formed, the reaction with diol (Diol) is formed a urethane (urethane) bonds. Unlike the prepolymerization, the chain extension reaction is faster and has an exothermic reaction. Thus, the solution is polymerized using a polar solvent such as DMAc or DMF for uniform reaction.

As a prior art for producing polyurethane-based elastic fibers, Korean Patent Publication No. 196651 discloses a ratio of unreacted diisocyanate by stirring glycol and diisocyanate (reaction molar ratio: 1.5-1.64) in a homogeneous mixer at 40-50 ° C. This 4 mol% or less primary polymer was produced and the chain extension comprised from 74-80 mol% ethylenediamine, 19-25 mol% 1,2-diaminopropane, and 0.2-0.8 mol% diethyltriamine. A method for preparing a polyurethane-based polymer by zero chain extension reaction has been proposed.

However, the prior art has many problems.

First, the temperature (40 ~ 50 ℃) for mixing the glycol and diisocyanate in the production of the primary polymer is too wide a range to achieve a uniform mixing. For example, since the reaction between glycol and diisocyanate occurs very vigorously, at 45 ° C or higher, a considerable proportion of the reaction proceeds together before uniform mixing occurs. As a result, it is difficult to achieve uniform mixing, and there is a high possibility that many reactions proceed and a lot of gels are generated before uniform mixing is performed.

On the other hand, in order to maintain the temperature below 42 ° C, the supply temperature of diisocyanate or glycol should be adjusted to 42 ° C or less before input to the homogeneous mixer. However, when the diisocyanate is out of 43 ~ 44 ° C., the increase rate of impurities such as dimer increases rapidly. Therefore, in order to maintain the mixing temperature in the homogeneous mixer below 42 ℃, it is necessary to install a heat exchanger in front of the homogeneous mixer or to control the temperature by attaching an outer jacket to the homogeneous mixer itself. This method can be said to be quite unreasonable compared to the method of mixing at the same temperature (43 ~ 44 ℃) the storage temperature of the diisocyanate in terms of equipment and management.

In addition, since the prior art adds and uses excessive diethyltriamine (0.2 to 0.8 mol%) in the chain extender, heat resistance and heat setting efficiency may be improved to some extent during post-processing, but excessive crosslinks are introduced into the polymer. The linearity of the polymer is poor and the phase flow of the polymer before radiation is severely reduced, making stabilization of the polymer due to phase separation difficult. As a result, the prior art has a limit that can not increase the spinning speed to more than 650m / min.

In addition, Japanese Patent Laid-Open No. 4-100919 proposes a method in which only 0.18% by weight of ethylenediamine relative to the polymer is used as a chain extender, and triamine, tetraamine, pentaamine, and the like are added to the polymer before the spinning process. However, the method has a problem that the viscosity stability of the polymer before radiation is very unstable, the radioactivity is poor, and the heat resistance is excellent, but the heat setting efficiency is bad.

In addition, US Patent No. 5,362,432 proposes a method of using a mixture of 83-92 mol% ethylenediamine and 8-17 mol% 1,2-diaminopropane as a chain extender. However, the method has a relatively high amount of ethylenediamine having good filling properties, so that the viscosity stability of the pre-spinning polymer is poor, making it difficult to control the process, and the heat stability of the manufactured elastic fiber is deteriorated.

In addition, US Patent No. 5,981,686 proposes a method of using a mixture of 10 to 65 mol% of ethylenediamine and 35 to 90 mol% of 1,3-diaminopentane as a chain extender. The patent mentions that amines of three functional groups, such as diethylenetriamine, can be selectively mixed and used in chain extenders or chain stoppers to impart some crosslinking to the polymer. However, in this patent, the amount of diethyltriamine used is not clearly stated. In addition, US Pat. No. 5,000,899 describes a method of using a mixture of 50 to 80 mol% of ethylenediamine and 20 to 50 mol% of 2-methylpentamethylenediamine as a chain extender.

In the chain extenders of U.S. Patent Nos. 5,981,686 and 5,000,899, 2-methylpentamethylenediamine and 1,3-diaminopentane have a longer chain and have 5 carbon atoms than ethylenediamine or 1,2-diaminopropane. It has the properties of odd chains and the same properties with somewhat bulky side chains such as methyl and ethyl. Due to these properties, the U.S. patents have a problem of insufficient heat resistance because they prevent internal crystallization of polymers or elastic fibers, that is, crystallization due to rearrangement of hard and soft segments by phase separation. In this case, when the heat resistance is insufficient, the property retention rate is lost, and the unique properties of the elastic fibers are lost.

The present invention is to solve the problems of the prior art to improve the viscosity stability of the polymer to provide a method of producing a polyurethane-based elastic fiber that is excellent in spinning even during high-speed spinning, can significantly reduce the occurrence of wave yarn. In another aspect, the present invention is to provide a polyurethane-based elastic fiber excellent in the bonding strength between heat resistance, heat stability and monofilament.

In the present invention, in manufacturing a polyurethane-based elastic fiber, in the continuous pipe of the form of a continuous pipe consisting of a homogeneous mixer, a temperature riser, a reactor and a cooler to prepare a prepolymer under the following conditions, the prepolymer chain extension / chain stop The present invention relates to a method for producing a polyurethane-based elastic fiber, characterized in that the reaction to produce a polymer, and adding an additive to the polymer.

--- below ---

[Prepolymer Manufacturing Process]

(Iii) a high molecular weight polyol and an excess of diisocyanate are mixed in the homogeneous mixer under the condition that the shear rate is 20 sec ⁻¹ or more in the absence of internal mixing mechanism, and (ii) the high molecular weight polyol and excess The mixture of the diisocyanate of the first reaction in the condition that the shear force in the absence of the internal mixing mechanism in the temperature increaser 3sec ^-1 or more, and (iii) the shear force in the absence of the internal mixing mechanism in the reactor The prepolymer is prepared by secondary reaction under the conditions of 0.1 sec ⁻¹ or more.

The present invention also relates to a polyurethane-based elastic fiber having a bonding force of 145 mgf or more between monofilaments.

Hereinafter, the manufacturing method of this invention is demonstrated in detail.

In the present invention, a continuous pipe in the form of a cylindrical pipe having a mixing element in the form of Kenics or Sulz is used to impart a shear rate when preparing the prepolymer. . The continuous polymerization tube is composed of a homogeneous mixer, a temperature riser, a polymerizer and a cooler. The uniform mixing is the shear rate in the absence of the mixing mechanism (Mixing Element) in the interior of the shear rate in, without a mixing mechanism within the group such that the elevated temperature 20sec ^-1 or more so that the 3sec ^-1 or more, and the reactor internal Shear rate is designed to be 0.1sec ^-1 or more in the absence of mixing mechanism.

In the present invention, first, a high molecular weight polyol and an excess of diisocyanate are mixed in a homogeneous mixer having a shear rate of 20 sec ⁻¹ or more in the absence of an internal mixing mechanism, and then the mixture is mixed in the absence of an internal mixing mechanism. after the reaction at a shear w warmth than 3sec ^-1, the shearing force in the continuously without internal mixing mechanism status is reacted in less than 0.13sec ^-1 reactor to produce a prepolymer.

In this case, polytetramethylene ether glycol having a number average molecular weight of about 1700 to 3000 and 4,4'-methylenediphenyl diisocyanate are used as raw materials to be used for preparing a polyurethane-based elastic polymer. At this time, the molar ratio of diisocyanate per glycol is suitably about 1.5-1.75. In the process of preparing the prepolymer, it is very important to properly control the shear force (shearate) in the mixer, the temperature riser and the reactor because three-dimensional crosslinking occurs easily due to heterogeneous mixing and reaction.

In the homogeneous mixer, the shear force (shearate) that the raw material mixture of the prepolymer receives is set to 20 sec ⁻¹ or more in the absence of a mixing element inside. In this case, when the shear force is less than 20 sec ^-1 , since the raw material monomers are not mixed uniformly, a lot of gels are formed, thereby causing problems of deterioration of radioactivity and quality.

On the other hand, it is more preferable to adjust the mixing temperature in a mixer at 43-44 degreeC. If the mixing temperature is more than 45 ℃ a significant amount of the reaction proceeds at the same time before complete homogeneous mixing can form a three-dimensional crosslinking gel. The gel components thus formed may accumulate in the homogeneous mixer or be moved to the next stage, which may shorten the replacement cycle of the homogeneous mixer or adversely affect the quality of the final prepolymer.

In addition, the formed gels may affect the final spinning process, causing deterioration of radioactivity and wave yarns, and adversely affect physical properties of the finally produced elastic yarn. On the other hand, when the mixing temperature is less than 43 ℃ may lower the mixing temperature than the storage temperature of the general diisocyanate may cause a problem requiring additional equipment supplement.

On the other hand, it is very important to set the shear force (shearate) in the temperature riser to 3 sec ⁻¹ or more in the absence of an internal mixing mechanism. If the shear force is less than 3 sec ⁻¹ , heterogeneous reactions occur and gel formation increases in the prepolymer.

The rate of temperature rise in the temperature riser and the final temperature of the prepolymer heated up are also important. It is good to avoid sudden temperature increase and to maintain the final temperature of the prepolymer to be 90 ℃ or less. Generally, when the reaction temperature of the prepolymer exceeds 90 ° C, the rate of advancing of side reactions is increased, which increases the possibility of gel generation. In addition, since the reaction of glycol and diisocyanate, which is a raw material of the prepolymer, is an exothermic reaction, the exothermic reaction should be controlled by controlling the temperature rise time well.

If the temperature increase time is too fast, it is difficult to control the exotherm generated in the reaction, so the temperature of the preliminarily heated prepolymer is more than 90 ° C. In addition, if the temperature increase rate is too slow, the same raw material supply may increase the equipment of the temperature increaser may cause a burden of additional equipment installation.

On the other hand, it is very important to set the shear rate in the reactor to 0.1 sec ^-1 or more in the absence of an internal mixing mechanism. If the shear force is less than 0.1 sec ^-1 , a lot of gels are generated due to the heterogeneous reaction. At this time, it is good to manage the reaction temperature in the reactor to 80 ~ 90 ℃ or less. If the reaction temperature exceeds 90 ° C, there is a high possibility that the side reaction proceeds at a high rate and gel is generated.

In the prepolymer manufactured through the above process, up to 600 gels are formed, thereby improving processability and quality of the final product. The number of gels in the prepolymer can be measured by Coulter Counter.

Next, a chain extender and a chain stopper are added to the prepolymer and reacted to prepare a polyurethane polymer. More specifically, the prepolymer is dissolved in N, N'-dimethylacetamide (hereinafter referred to as "DMAc") solvent to prepare a solution of the prepolymer, and then N, N'-dimethylacetamide of the diamine and triamine mixture. It is reacted with a solution (chain extender) and a N, N'-diethylacetamide solution of a monoamine (chain stopper). Herein, ethylenediamine and 1,2-diaminopropane may be used as the diamine used as the chain extender, and diethylenetriamine may be used as the triamine.

As a specific example of the chain extender solution, a solution consisting of 60 to 75 mol% of ethylenediamine, 24.9 to 39 mol% of 1,2-diaminopropane, and 0.1 mol% or less of diethyltriamine may be used. Diethylamine may be used as the monoamine in the chain stopper solution. The chain extender is used in 96 ~ 98.5 equivalent% based on the prepolymer and the chain stopper is adjusted to 4.5 ~ 7.0 equivalent% based on the prepolymer. The chain extender solution and the chain stopper solution may be separately supplied and react with the prepolymer solution, or may be simultaneously supplied with the prepolymer solution.

The concentration of the polyurethaneurea-based polymer (hereinafter referred to as "final polymer") thus formed is 36 to 38.5 wt%, depending on the amount of N, N'-dimethylacetamide solvent that dissolves the prepolymer, and the number average molecular weight is 30,000. ~ 5 million. The number average molecular weight can be measured by Gel Permeation Chromatography (GPC).

Next, in the homogeneous mixer, the polyurethane-based polymer and the additive are mixed under the condition that the shear force in the absence of the internal mixing mechanism is 0.13 sec ⁻¹ or more to prepare a dope immediately before spinning. The additive may optionally include triamine compounds, more specifically diethylenetriamine, conventional antioxidants, anti-yellowing agents, UV stabilizers, dyeing enhancers, quenchers, radioactive enhancers, and the like.

In particular, when diethylenetriamine is used as an additive rather than a chain extender, crosslinking is formed at high temperature to improve heat resistance of the elastic fiber, and precipitation phenomenon due to reaggregation of inorganic additives is prevented. Mixing effect can be obtained. At this point, uniform mixing of the additives and the final polymer is important. Uneven mixing of the additive and the final polymer causes wave yarns to occur in the elastic fibers spun by the additive components that are not uniformly dispersed and mixed, causing trimming during spinning. In addition, the bonding force between each filament is lowered, causing problems such as cracking of the filament during post-processing, which adversely affects the workability and the quality of the paper.

In order to uniformly mix the final polymer and the additive, a static mixer of a cylindrical pipe is used. The homogeneous mixer has a shear rate of at least 0.13 sec ⁻¹ or more in the absence of an internal mixing element.

The storage temperature of the additive slurry mixed with the final polymer is important. If the storage temperature of the additive slurry exceeds 60 ℃, the viscosity of the additive slurry is increased and the factor of withdrawal is greater than the lowering factor of the precipitation rate due to the micro-brown movement of each additive component. The faster the additive slurry, the worse the quality of the additive slurry and the faster the clogging cycle of the additive filter, which adversely affects quality and production.

In addition, when the storage temperature of the additive slurry is less than 40 ° C, the relative viscosity of the additive slurry increases due to the temperature, and the differential pressure of the additive filter is increased, which acts as an unstable factor in the process. Higher speeds reduce the quality of the additives and the clogging cycle of the filter. Therefore, the storage temperature of the additive slurry is preferably maintained in the range of 40 ~ 60 ℃.

Next, the polyurethane woven fiber was dried in a dry spinning method to evaporate the solvent contained in the dope while pushing a predetermined amount of the spinning dope prepared in this manner into a spinning cylinder having an atmosphere of 180 to 280 ° C. using a gear pump. Manufacture. In the dry spinning process, the final polymer (dope) containing various additives is converted into a real state and undergoes another chemical change called transamidation or aminolysis by high temperature heat. This secondary chemical change results in an increase in molecular weight as the dope changes to the real state. The number average molecular weight of the elastic fiber produced in the present invention is about 40,000 ~ 70,000. The number average molecular weight of the elastic yarn can also be measured by GPC (Gel Permeation Chromatography). In the present invention, it is appropriate to set the spinning speed to 800 to 1200 m / min.

The spinning dope prepared by the present invention has a low gel content, and the additives are uniformly mixed / dispersed, so that the spinning is excellent in spinning and the generation of wave yarn is significantly reduced. In addition, the polyurethane-based elastic fiber of the present invention prepared with the spinning dopant is used because the appropriate amount of triamine is used as a chain extender and additive, so that the appropriate tertiary crosslinking occurs, the heat resistance, heat setting and bonding between the monofilament is very excellent do. Specifically, the strong retention rate is 54% or more and the bonding force between monofilaments is 145 mgf or more.

In the present invention, the gel particle number of the prepolymer, the molecular weight of the final polymer and the elastic yarn, the viscosity stability, heat resistance and heat setting efficiency of the final polymer and the like are measured as follows.

Gel particle number of the prepolymer: The prepolymer is dissolved in 0.5% concentration in 1% LiCl DMAc electrolyte and measured using a Coulter Counter (Coulter, UK).

Viscosity stability of final polymer: The rate of viscosity rise is measured while measuring the viscosity of the polymerized final polymer in a 50 ° C. oven for 3 days in units of 2 hours. Viscosity measurement was performed using a Brookfield RV viscometer, the spindle was set at No. 07 and the spindle rotation was set at 10 rpm.

Molecular weight of final polymer and elastic yarn : The sample is dissolved in 0.05M-LiCl DMF solution at 0.05% concentration and measured using GPC (Gel Permeation Chromatoraphy). At this time, the calibration reference material used for calibration used polyethylene oxide, and the GPC instrument used for the measurement used the product of Waters.

-Determination of wave company : A 10cm long sample is stretched to 500% at a constant speed of 500% / 30sec, left for 1 minute in the stretched state, and then relaxed again. After the relaxation, the state of the thread is observed, and if there are two or more curved or tortuous nodes within a length of 10 cm, the yarn is judged as wave yarn. The incidence of wave yarn is a percentage of the number generated by examining 5000 yarns.

Heat resistance and heat setting efficiency : After extending the 10cm length sample to 15cm, treat it for 70 seconds in a 195 ℃ hot air oven, cool it for 2 hours in a relaxed state under standard temperature and humidity conditions, and then again boil it in 100 ℃ boiling water for 30 minutes. Process. The strength and the change in length of the sample before and after the heat treatment are measured, and the heat resistance is determined based on the strong maintenance rate, and the heat setting efficiency is determined based on the rate of change of the length of the sample. Strong retention rate and length change rate were calculated as follows. The higher the retention rate, the better the heat resistance. The higher the length change rate, the better the heat setting efficiency.

Bonding force between monofilaments : In a polyurethane-based elastic yarn composed of several filaments, one strand of monofilament is separated about 5 cm, and each end of the monofilaments attached together without being separated from the separated monofilament is separated from each other. And the non-separated monofilaments are mounted on an Instron machine equipped with a load cell of 1kg or less so that the contact point where the monofilaments are bonded is placed at the center of the 5cm cage, and then stretched at a constant speed of 1000% / min to separate the separated single-stranded monofilaments. Measure the force when the remaining monofilaments are separated by elongation. The result is the average value of the measured values obtained by measuring the average value of the bonding force during elongation and at least three times for each sample.

Example 1

1800 molecular weight polytetramethylene ether glycol and 1 mole of 4,4'-diphenylmethane diisocyanate, 1.65 mol of the internal mixing mechanism is a shear rate of 20sec ^-1 homogeneous mixture and mixing the internal mechanism in the absence of using a metering pump The mixture is put into a cylindrical pipe-type continuous polymerization tube consisting of a reactor and a cooler having a sheer rate of 0.1 sec ^-1 and a mixer having a sheer rate of 3sec ^-1 in the absence of an internal mixing mechanism and a homogeneous mixer. The reaction was carried out for 110 minutes while maintaining the temperature at 43.5 ° C., the temperature at the temperature riser terminal at 89 ° C., and the reactor temperature at 88 ° C., respectively, to synthesize a prepolymer having isocyanate at the sock end. Subsequently, after cooling the prepolymer to 40 ° C., N, N′-dimethylacetamide was added to prepare a solution containing 45% of a prepolymer. Subsequently, the prepolymer solution was lowered to 5 ° C., followed by vigorous stirring, and the chain extender N consisting of 59.9 mol% of ethylenediamine, 40 mol% of 1,2-diaminopropane, and 0.1 mol% of diethylenetriamine was added to the prepolymer. The final polymer was prepared by supplying 98.5 equivalent% of N, N'-dimethylacetamide solution and 6.5 equivalent% of N, N'-dimethylacetamide solution of chain stopper composed of diethylamine single component. The number average molecular weight of the final polymer thus produced was 31,000, contained 38.5% solids, and the viscosity was 2100 poise at 40 ° C. 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzene) -1,3,5-triazine-2,4, 1.2% by weight of 6- (1H, 3H, 5H) trione antioxidant, 1,1,1 ', 1'-tetramethyl-4,4'-(methylene-di-p-petylene) dicemicarbazide Waste gas stabilizer 1.0 wt%, N- (4-ethoxycarbonylphenyl) -N-methyl-N-phenylformamidine UV stabilizer 1.5 wt%, titanium oxide 2 wt%, blue pigment (ultramarine blue) 0.01 wt% And 0.2 wt% of diethylenetriamine and uniformly mix the additive slurry stored at 45 ° C. using an additive homogeneous mixer equipped with an internal mixing apparatus having a shear rate of 0.13 sec ⁻¹ in the absence of an internal mixing apparatus. The dope was prepared just before spinning. Thus prepared dope was dry-spun using a spinning barrel having a temperature distribution between 260 ℃ 200 ℃ to prepare a polyurethane elastic yarn of 40 denier. The results of measuring the number of gel particles of the prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarns, the heat resistance, the heat setting efficiency and the bonding strength between the monofilaments in the manufacturing process of the polyurethane elastic yarns are shown in Table 1 Same as

Example 2

Change the molar ratio of ethylenediamine, 1,2-diaminopropane and diethylenetriamine to the chain extender mixture to 75: 24.9: 0.1 and 96.0 equivalent% of the chain extender and 7.0 equivalent of the chain stopper for the prepolymer. A polyurethane elastic yarn was manufactured in the same manner as in Example 1, except that the product was changed to%. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Example 3

Polyurethane elastic yarn was manufactured in the same manner as in Example 1, except that the content of diethylenetriamine applied to the additive was changed to 0.1 wt%. The results of measuring the number of gel particles of the prepared prepolymer, the rate of viscosity increase of the final polymer, the frequency of wave yarn production, the heat resistance of the manufactured elastic yarn, the heat setting efficiency, and the bonding force between the monofilaments are shown in Table 1.

Example 4

Polyurethane elastic yarn was manufactured in the same manner as in Example 1, except that the content of diethylenetriamine applied to the additive was changed to 0.3 wt%. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Comparative Example 1

In the structure of the continuous polymerization tube, the shear rate in the absence of the internal mixing mechanism is used in the continuous polymerization tube designed as the homogeneous mixer 19sec ^-1 , the temperature riser 2.8sec ^-1 , and the reactor 0.09sec ^-1 , and there is no internal mixing mechanism The shear rate of the additive homogeneous mixer at 0.1sec-1, the temperature of the homogeneous mixer at 49 ° C, the temperature of the prepolymer heated at 95 ° C, the reactor temperature at 93 ° C, and the storage temperature of the additive slurry at 65 ° C. Except for producing a polyurethane elastic yarn in the same manner as in Example 1. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Comparative Example 2

Polyurethane elastic yarns were manufactured in the same manner as in Example 1, except that a chain extender composed of 70 mol% of ethylenediamine and 30 mol% of 2-methylpentamethylenediamine was used, and diethylenetriamine was not included in the additive component. It was. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Comparative Example 3

The continuous polymerization tube for preparing the prepolymer and the additive homogeneous mixer were applied in the same manner as in Comparative Example 1, and only ethylenediamine was used as the chain extender, and diethylenetriamine was added to the additive by adding 0.18% by weight to the solids of the polymer. Except for the manufacture of polyurethane elastic yarn was prepared in the same manner as in Example 1. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Comparative Example 4

A continuous polymerization tube for preparing a prepolymer and an additive homogeneous mixer were applied in the same manner as in Comparative Example 1, and a chain composed of 80 mol% of ethylenediamine, 19.8 mol% of 1,2-diaminopropane, and 0.2 mol% of diethylenetriamine. A polyurethane elastic yarn was manufactured in the same manner as in Example 1, except that the extender was used. The results of measuring the gel particle number of the prepared prepolymer, the rate of increase of the viscosity of the final polymer, the frequency of wave yarn generation, the heat resistance of the prepared elastic yarn, the heat setting efficiency and the bonding force between the monofilaments are shown in Table 1.

Evaluation / Measurement Results division Number of Gels in Prepolymer Viscosity Rising Rate (Poise / Hr) Wave Death Rate (%) Strong retention rate (%) Heat setting efficiency (%) Adhesion (mgf) Example 1 500-600 25 0.1 59 39 145 Example 2 500-600 29 0.1 62 35 150 Example 3 500-600 27 0.13 54 41 148 Example 4 500-600 26 0.08 65 33 152 Comparative Example 1 800 ~ 1200 31 0.25 54 40 105 Comparative Example 2 800 ~ 1200 26 0.24 42 42 120 Comparative Example 3 800 ~ 1200 48 0.31 68 17 124 Comparative Example 4 800 ~ 1200 36 0.28 55 39 119

The elastic fiber of the present invention is excellent in heat resistance (strength retention), heat setting and bonding between the monofilament. The production method of the present invention improves the stability of the polymer, good radiation properties even at high speed spinning, it is possible to significantly reduce the generation of wave yarn.

Claims (7)

In preparing polyurethane-based elastic fibers, a prepolymer is prepared under the following conditions in a continuous pipe in the form of a circular pipe composed of a homogeneous mixer, a temperature riser, a reactor, and a cooler, and then the polymer is subjected to chain extension / stoppage reaction. To prepare a method for producing a polyurethane-based elastic fiber, characterized in that the additive is added to the polymer. --- below --- [Prepolymer Manufacturing Process] (Iii) a high molecular weight polyol and an excess of diisocyanate are mixed in the homogeneous mixer under the condition that the shear rate is 20 sec ⁻¹ or more in the absence of internal mixing mechanism, and (ii) the high molecular weight polyol and excess The mixture of the diisocyanate of 1 is first reacted in a condition that the shear force in the absence of the internal mixing mechanism in the temperature riser 3sec ^-1 or more, and (i) the shear force in the absence of internal mixing mechanism in the reactor The prepolymer is prepared by secondary reaction under the conditions of 0.1 sec ⁻¹ or more. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein the homogeneous mixer temperature is 43 to 44 DEG C during prepolymer production. The method of manufacturing a polyurethane-based elastic fiber according to claim 1, wherein the temperature riser temperature of the prepolymer is 90 ° C or less. The method for preparing a polyurethane-based elastic fiber according to claim 1, wherein the reactor temperature is 80 to 90 ° C during preparation of the prepolymer. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein during the chain extension / stoppage reaction, 96 to 98.5 equivalent% of a chain extender and 4.5 to 7.0 equivalent% of a chain stopper of diethyleneamine are added. The method for producing a polyurethane-based elastic fiber according to claim 1, wherein the polyurethane-based polymer and the additive, which have been polymerized, are mixed in a homogeneous mixer under a shear force of 0.13 sec ⁻¹ or more. Polyurethane-based elastic fiber, characterized in that the bonding force between the monofilament is 145mgf or more.