JP2001234430A - Polyurethane elastic fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a product excellent in releasability, an appearance grade, a fit, a wearable property, a wear sensation, chemical resistance, etc. SOLUTION: A polyurethane elastic fiber features being made of a polyurethane composed of a polyol which comprises a random copolymer between tetrahydrofuran and ethylene oxide and/or propylene oxide, a diisocyanate and a diol as principal components, and comprising a high polymer soluble in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane elastic fiber having excellent elastic properties without settling even at a low temperature, and having both good elongation and recovery, and a method for producing the same.

[0002]

2. Description of the Related Art Elastic fibers are widely used for elastic clothing such as legwear, innerwear, and sportswear and for industrial materials because of their excellent elasticity.

As such elastic fibers, polyurethane elastic fibers are used, which are disclosed in JP-A-63-235320, JP-A-5-239177 and JP-A-2-1-1.
No. 9511 discloses a technique for spinning a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran, and a polyurethane polymer comprising an organic diisocyanate and a diamine compound.

[0004]

However, the polyether polyurethane elastic fiber exhibits excellent rubber elasticity at room temperature, but the rubber elasticity decreases when the environmental temperature decreases, and the knitting process is performed in a low temperature environment in winter. Is performed, the size of the knitted product fluctuates due to a temperature change, and there is a problem that the finished product is not uniform.

At a low temperature, for example, at a temperature of 0 ° C. or less, rubber elasticity is impaired. Therefore, it may not be used as a material for aquaculture nets and the like which may be used under the freezing condition. could not.

Accordingly, there has been a demand for an improvement in the elastic recovery characteristics (cold resistance) of polyether polyurethane elastic fibers at low temperatures.

[0007] Furthermore, in the prior art, when elastic fibers are used in clothes or the like, the appearance quality, fit, wearability, wearability, and chemical resistance have not been improved.

[0008] The present invention has excellent elastic properties without settling even in a low temperature environment, and has excellent appearance quality, fit, wearability, wear feeling, chemical resistance, etc., which could not be obtained by conventional techniques. An object of the present invention is to provide a polyurethane elastic fiber capable of obtaining an excellent product and a method for producing the same.

[0009]

Means for Solving the Problems The polyurethane elastic fiber of the present invention employs the following means to solve the above-mentioned problems.

That is, a polyurethane whose main component is a polyol, diisocyanate or diol, wherein the polyol contains a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide and is soluble in an organic solvent. A polyurethane elastic fiber characterized by containing a polymer substance.

The method for producing a polyurethane elastic fiber of the present invention employs the following means in order to solve the above-mentioned problems.

That is, a polyol containing a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide, a diisocyanate and a diol as main constituents, and a polyurethane containing a polymer substance soluble in an organic solvent as a solute. A method for producing a polyurethane elastic fiber, comprising spinning a polyurethane solution described below.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the polyurethane elastic fiber of the present invention will be described in more detail.

The polyurethane elastic fiber of the present invention is a polyurethane whose main constituents are polyols, diisocyanates and diols.

The method for synthesizing the polyurethane is not particularly limited. In particular, polymerization is preferably performed in a solution from the viewpoint of efficiently performing the reaction. Note that trifunctional or higher polyfunctional glycols and isocyanates may be used as long as the effects of the present invention are not impaired.

Here, typical structural units constituting the polyurethane in the present invention will be described.

The polyol used in the present invention has excellent cold resistance and high elongation, and from the viewpoint of obtaining a material having high recovery, tetrahydrofuran (hereinafter referred to as T).
A so-called random copolymer in which HF) and ethylene oxide and / or propylene oxide are arranged irregularly is used.

In the present invention, when a block copolymer is used, the resulting polyurethane elastic fiber has remarkable water absorption, and thus has a problem that the physical properties at the time of water absorption are reduced.

That is, the polyol used in the present invention is also expressed as a copoly (alkylene ether) glycol selected from poly (tetramethylene-co-ethylene ether) glycol and poly (tetramethylene-co-1,2-propylene ether) glycol. Can be done.

The polyol used in the present invention preferably has a molar fraction of ethylene oxide units and / or propylene oxide units of 5 to 90%.

The poly (tetramethylene-co-
Ethylene glycol), the ethylene oxide unit is 15 to 3 relative to the total alkylene ether.
It is preferably contained in an amount of 7 mol%, preferably 20 to 35 mol.
% Is more preferable.

Further, poly (tetramethylene-co-1,2)
-Propylene ether) glycol;
The propylene oxide unit is preferably contained in an amount of 15 to 30 mol% based on all alkylene ethers.

Further, the polyol used in the present invention may be composed of only a random copolymer, may be a copolymer copolymerized with another polyol, or may be a copolymer mixed with another polyol. It may be.

As other polyols, excellent cold resistance,
Poly (1,4-tetramethylene glycol) (hereinafter abbreviated as PTMG), Patent No. 261513, from the viewpoint of obtaining a material having high extensibility and high recoverability.
No. 1, diol containing a neopentyl group in the main chain, polycarbonate diol disclosed in JP-A-2-289616, etc., JP-A-5-9851
No. 1, the ester-based diols disclosed in
It is preferable to use 4-butanediol, 1,6-hexanediol, polycaprolactonediol, polyethylene ether glycol, polypropylene ether glycol, a copolymerized polyol of neopentylene oxide and tetrahydrofuran, or the like. And such another polyol may be one kind, or may be two or more kinds.

The weight average molecular weight of the polyol used in the present invention is preferably in the range of 1,000 or more and 6000 or less from the viewpoint of elongation, strength, heat resistance and the like when formed into a yarn.

More preferably, the range is from 1300 to 4500. By using a polyol having a molecular weight in this range, polyurethane elastic fibers having well-balanced mechanical properties can be obtained.

Next, the diisocyanate used in the present invention is
For example, 5-isocyanate-1- (isocyanatomethyl) -1,3,3-trimethylcyclohexane, 1-
Isocyanate-4-[(4-isocyanatophenyl) methyl] benzene, 1-isocyanate-2-
[(4-Isocyanate-phenyl) methyl] benzene, 1,1′-methylenebis (4-isocyanatocyclohexane), 4-methyl-1,3-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate (hereinafter abbreviated as MDI) ), 2,4-tolylene diisocyanate (hereinafter abbreviated as TDI), 1,4-
Aromatic diisocyanates such as diisocyanate benzene, xylylene diisocyanate, and 2,6-naphthalenedi isocyanate are particularly preferable for synthesizing polyurethane having high heat resistance and strength.

Further, as an alicyclic diisocyanate, for example, methylene bis (cyclohexyl isocyanate)
(Hereinafter abbreviated as H ₁₂ MDI), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate,
Preferred are cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, octahydro 1,5-naphthalenediisocyanate, and the like. Aliphatic diisocyanates are preferably used particularly for suppressing yellowing of polyurethane yarns.

These diisocyanates may be used alone or in combination of two or more.

The ratio of the molar amounts of such diisocyanates is:
From the viewpoint of the strength characteristics of the obtained elastic resin, polyol 1
On the other hand, the diisocyanate is preferably in the range of 1.2 or more and 2.3 or less.

Next, a low molecular weight diol is used as a chain extender used in the present invention.

The low molecular weight diols include ethylene glycol, 1,3 propanediol, 1,4 butanediol, 1,2-propylene glycol, 3-methyl-1,
5-pentanediol, 2,2-dimethyl-1,3-trimethylenediol, 2,2,4-trimethyl-1,5
-Pentanediol, 2-methyl-2-ethyl-1,3
-It is preferable to use propanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate and the like.

It is also preferable to use one or more of these materials. In particular, from the viewpoint of obtaining a polyurethane elastic fiber having high heat resistance and high strength as a diol-extended polyurethane, ethylene glycol,
It is preferable to use 1,3 propanediol, 1,4 butanediol and the like.

The polyurethane elastic fiber of the present invention contains a polymer substance soluble in an organic solvent.

In the present invention, the organic solvent refers to, for example, DMAC, DMF, DMSO, NMP and the like, which will be described later, and those containing these as main components.

As a polymer substance soluble in an organic solvent, polyvinylpyrrolidone (hereinafter abbreviated as PVP) and at least one of copolymers thereof, polyvinylidene fluoride and the like are preferable.

By containing the above-mentioned polymer substance, the heat setting property and the mechanical setting property (residual strain) of the obtained polyurethane elastic fiber can be improved, and the breaking strength and the breaking elongation can be increased. it can.

The content of at least one of PVP and its copolymer is preferably in the range of 0.1% by weight or more and 15% by weight or less.
From the viewpoint of making the strength, elongation, and heat setting property particularly good, the range of 1% by weight or more and 10% by weight or less is more preferable.

It is preferable that the content is tested in advance depending on the application and a desired value is appropriately determined.

In the present invention, the copolymerization compound used for synthesizing the copolymer of PVP is not particularly limited. For example, N-isopropenyl 2-pyrrolidone, N-vinyl 4-methyl 2- Pyrrolidone, N-vinyl piperidone, N-vinyl caprolactam, N-vinyl enantholactam, N-vinyl valerolactam, N-butenyl-2,4-di (1-butenyl) -2-pyrrolidone vinyl acetate, dimethylaminoethyl methacrylate, Styrene, acrylic acid, or the like can be used. These copolymers may be either block copolymers or random copolymers.

Further, the polyurethane elastic fiber is used in the present invention from the viewpoint of setting the characteristics of the polyurethane elastic fiber as target characteristics and further preventing practically no dropout of at least one of PVP and its copolymer in practical use. The K value of at least one of PVP and its copolymer is preferably in the range of 20 to 70.

In the present invention, the K value is a value calculated from the viscosity equation of Fikenscher.

Particularly preferred as PVP and its copolymer are those in which PVP and its copolymer are synthesized using isopropyl alcohol as a solvent. PVP and its copolymers synthesized using isopropyl alcohol as a solvent have a low content of pyrrolidone as a by-product, and PVP and its copolymers themselves are less likely to be colored, and in the production process, etc. This is preferable because it does not cause a problem.

Next, the polyvinylidene fluoride used in the present invention is not particularly limited, and includes those polymerized by a high-pressure method or a low-pressure method, and those obtained by decomposing a polymer once polymerized to a high molecular weight to reduce the molecular weight. No.

The carbon skeleton of the molecule may be linear or branched by selecting an appropriate catalyst species in the polymerization process.

Among the polyvinylidene fluorides, a particularly preferred carbon skeleton structure is a straight-chain structure. When the carbon skeleton structure of polyvinylidene fluoride is a straight-chain type, the strength and elongation of the obtained polyurethane yarn are particularly improved.

The preferred polyvinylidene fluoride preferably has a number average molecular weight in the range of 300 to 300,000. Number average molecular weight is GPC
It is a polystyrene equivalent value.

Dispersion and dissolution in polyurethane are fast,
With good spinnability, in particular, due to heat reception in the dry spinning step, the content of polyvinylidene fluoride is reduced, and from the viewpoint of not causing discoloration of the yarn, those particularly preferred as polyvinylidene fluoride have a number average molecular weight of, 300 to 300,000, 240 ° C, shear rate 50s
Melt viscosity at ec ^-1 is more than 5000 poise and 5000
It is less than 0 poise.

The content of polyvinylidene fluoride used in the present invention is preferably in the range of 0.1% by weight to 20% by weight, more preferably in the range of 1% by weight to 18% by weight. When the content of polyvinylidene fluoride is in the range of 1% by weight or more and 18% by weight or less, heat setting property, setting property,
The strength and elongation become particularly good.

It is preferred that these characteristic values are tested in advance depending on the use of the polyurethane yarn, and the molecular weight, viscosity and content of polyvinylidene fluoride are determined.

The polyurethane elastic fiber of the present invention may be used as a so-called BHT or "Sumilyzer" G manufactured by Sumitomo Chemical Co., Ltd. as an ultraviolet absorber, an antioxidant or a gas-resistant stabilizer.
Hindered phenol drugs such as A-80, benzotriazole drugs such as various "tinuvins", "Sumilyzer" manufactured by Sumitomo Chemical Co., Ltd.
Phosphorus drugs including P-16, hindered amine drugs including various "tinuvins", inorganic pigments including titanium oxide, zinc oxide, carbon black, metal soaps including magnesium stearate, In addition, bactericides and deodorants containing silver, zinc and their compounds, lubricants such as silicone and mineral oil, various antistatic agents including barium sulfate, cerium oxide, betaine and phosphoric acid, etc. Or
It is also preferred that it is reacted with a polymer.

In order to further enhance the durability especially against light and various types of nitric oxide, a nitric oxide supplement such as HN-150 manufactured by Nippon Hydrazine Co., Ltd.
For example, "Sumilyzer" GA- manufactured by Sumitomo Chemical Co., Ltd.
80, it is preferable to use a light stabilizer such as "Sumisorb" 300 # 622 manufactured by Sumitomo Chemical Co., Ltd.

The fineness and cross-sectional shape of the polyurethane elastic fiber of the present invention are not particularly limited. For example, the cross section may be circular or flat.

The polyurethane elastic fiber of the present invention has a temperature of -5 ° C.
Is preferably 90% or less, more preferably 50% or less, and even more preferably 26% or less.

Next, a method for producing the polyurethane elastic fiber of the present invention will be described.

In the present invention, it is preferable to prepare a polyurethane solution first.

In the present invention, any method may be used for producing a polyurethane solution which is a solute of a polyurethane solution or a polyurethane solution.

That is, either the melt polymerization method or the solution polymerization method may be used. However, more preferred is the solution polymerization method. In the case of the solution polymerization method, the generation of foreign substances such as gel in the polyurethane is small. Also, needless to say, solution polymerization is preferable from the viewpoint of production efficiency because labor for preparing a solution is omitted.

In the present invention, a polyurethane containing a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide, a polyurethane containing diisocyanate and a diol as main components is used.

Among these, the weight average molecular weight of the polyol is particularly in the range of 1,000 to 6,000, and the diol as a chain extender is at least one selected from the group consisting of ethylene glycol, 1,3 propanediol and 1,4 butanediol. The diisocyanate is preferably a polyurethane synthesized in a solution using MDI as a main raw material.

Such polyurethane is, for example, DMA
C, DMF, DMSO, NMP, or the like, or an organic solvent containing these as a main component, can be obtained by synthesizing the above-mentioned raw materials.

For example, the so-called one-shot method in which each raw material is charged and dissolved in such an organic solvent and heated to an appropriate temperature to react with polyurethane, or a polyol and MDI are first melt-reacted, and thereafter, A method in which the reactant is dissolved in an organic solvent and reacted with the above-mentioned diol to obtain a polyurethane can be employed as a particularly preferable method.

In synthesizing such a polyurethane,
An amine catalyst or an organometallic catalyst may be used alone or in combination of two or more. Typical examples thereof include amine catalysts such as N, N-dimethylcyclohexylamine, N, N-dimethylbenzylamine, triethylamine, N-methylmorpholine,
Ethylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethyl-1,3-propanediamine, N, N, N ', N'-tetramethylhexane Diamine, bis-2-dimethylaminoethyl ether, N, N, N ', N', N'-pentamethyldiethylenetriamine, tetramethylguanidine, triethylenediamine, N, N'-dimethylpiperazine, N-methyl-N'- Dimethylaminoethyl-piperazine, N- (2-dimethylaminoethyl) morpholine, 1-methylimidazole, 1,2-dimethylimidazole, N, N-dimethylaminoethanol, N, N,
N'-trimethylaminoethylethanolamine, N-
Methyl-N ′-(2-hydroxyethyl) piperazine,
2,4,6-tris (dimethylaminomethyl) phenol, N, N-dimethylaminohexanol, triethanolamine and the like can be used. Further, as the organic metal catalyst, tin octoate, dibutyl tin dilaurate, lead dibutyl octoate and the like can be used.

Further, in the present invention, it is also preferable to use a chain terminator in order to control the molecular weight of the polyurethane and the viscosity of the polyurethane spinning solution.

As such a chain terminator, n-butanol,
Diethylamine, cyclohexylamine, n-hexylamine and the like are preferred.

It is preferable that the chain terminator is usually used as a mixture with a chain extender.

Small amounts of trifunctional substances such as diethylenetriamine and glycerol can also be used to control polymer viscosity.

The concentration of the polyurethane solution thus obtained is not particularly limited, but is usually preferably in the range of 30% by weight to 80% by weight.

In the present invention, it is preferable to add a polymer substance soluble in the organic solvent and various additives to the polyurethane solution. An arbitrary method can be adopted as a method of adding to the polyurethane solution. Typical examples thereof include a method using a static mixer and a method using stirring.

Here, it is preferable that the polymer substance and various additives soluble in the organic solvent to be added are added in the form of a solution. If it is a solution, it can be uniformly added to the polyurethane solution.

In the present invention, a polyurethane solution is spun to obtain a polyurethane elastic fiber. The spinning method may be any of a wet method, a dry method, and a melting method.

From the viewpoint of increasing the spinning speed, spinning is preferably performed by a dry method. In dry spinning, at least two gas supply units are provided, and a gas suction unit is used to form a fiber by discharging a polyurethane solution from a spinneret to a spinning cylinder provided between the gas supply units. The temperature of the gas supplied from the gas supply unit provided at the lower part of the spinning cylinder is set to 6
The temperature is preferably set to 0 ° C. or lower from the viewpoint of eliminating yarn unevenness.

During spinning, the speed ratio between the godet roller and the winder is preferably determined according to the purpose of use of the yarn.

In the present invention, it is preferable that the speed ratio between the godet roller and the winder is 1.1 or more and 1.8 or less and winding is performed.

The spinning speed is 300 m / min or more and 800
It is preferably at most m / min.

[0076]

EXAMPLES The present invention will be described in more detail with reference to Examples. However, the present invention is not limited by these examples.

The method for quantifying various characteristics in the present invention will be described. [Stress relaxation, strength, residual strain, elongation] Stress relaxation, strength,
For residual strain and elongation, use polyurethane yarn with Instron 45.
It was obtained by performing a tensile test using a 02 type tensile tester.

The stress relaxation, strength and elongation were measured at 22 ° C., and the residual strain was measured at −5 ° C.

These are defined below.

A 5 cm (L1) sample was subjected to 300% elongation five times at a pulling speed of 50 cm / min. The stress at this time was defined as (G1).

Next, the length was held for 30 seconds. The stress after holding for 30 seconds was defined as (G2).

Next, the length of the sample when the elongation was recovered and the stress became 0 was defined as (L2).

Further, the polyurethane yarn was stretched for the sixth time until it was cut.

The stress at break was (G3) and the sample length at break was (L3).

The above characteristics were obtained by the following equations.

Strength = (G3) Stress relaxation = 100 × ((G1) − (G2)) / (G1) Residual strain (SET%) = 100 × ((L2) − (L
1)) / (L1) Elongation = 100 × ((L3) − (L1)) / (L1) [Heat setting property] Yarn is free and steamed at 100 ° C.
The mixture was then treated for 2 hours with free boiling water at 100 ° C. and dried at room temperature for one day. Next, the sample (length = (L
4)) was elongated by 100% (length = 2 × (L4)). The length was treated with steam at 115 ° C. for 1 minute. Further, at the same length, dry heat treatment at 130 ° C, and at the same length,
It was left at room temperature for one day.

Next, the stretched state of the yarn was removed, and its length (L5) was measured.

Heat setting property = 100 × ((L5) − (L
4)) / (L4) [Chemical resistance] The yarn was stretched and fixed at 100%, immersed in a hexane solution of oleic acid (5% by weight) for 24 hours, and then ethanol of N, N'-diethyltoluamide was added. Solution (0.
(5% by weight) for 1 hour. Thereafter, the yarn was dried at room temperature for 24 hours free of charge, and the breaking strength (G4) was measured. The retention rate of (G4) with respect to the breaking strength (G3) of the untreated yarn was defined as chemical resistance.

Chemical resistance = 100 × (G4) / (G3) [Quantitative determination method of PVP] 1 g of a sample was put into a Soxhlet extractor using dichloromethane as a solvent to extract at least one of PVP and its copolymer. did.

After distilling off the solvent, 20 ml of methanol was added.
The residue was dissolved and analyzed by high performance liquid chromatography. For quantification, a calibration curve was prepared in advance with a solution of PVP and its copolymer whose concentration was determined and used.
The content was determined by the following equation.

Content (% by weight) = (sample peak area / detection)
(Quantity curve peak area) x calibration curve sample amount / yarn sample weight [Quantitative determination method of polyvinylidene fluoride] 1 g of yarn sample (A)
DMA_CAdd 50 ml and dissolve the yarn completely.
Slowly add 100 ml of ethanol
And the remaining polyurethane solution is evaporated to dryness,
The polyurethane (B) was isolated in the yarn sample. next,
A predetermined weight ratio of polyurethane (B) and polyolefin
A calibration curve from the IR spectrum of the mixture of vinylidene fluoride
I had done it. The procedure is based on polyvinylidene fluoride content
Is 0% by weight, 1% by weight, 3% by weight, 6% by weight, 10% by weight
% And 20% by weight of each sample,
Ν (CO) in torr 1700cm ^-1~ 1800cm
^-1And ν (CF2) 890cm^-1The peak area ratio (X) of
I asked. For IR spectrum measurement, manufactured by PerkinElmer
FT-IR and its measurement sample is DMA_Cby
A cast film was used. Peak area ratio (X)
Calibration curve of polyvinylidene fluoride content (% by weight)
And the inclination (α) was obtained. Finally, yarn sample (A)
After washing with n-hexane, IR spectroscopy was performed under the same conditions.
The torr was measured. In the obtained spectrum, ν (C
O) 1700cm^-1~ 1800cm^-1And ν (CF2) 8
90cm^-1Was determined as the peak area ratio (Xs).

Polyvinylidene fluoride content (% by weight) =
(Α) × (Xs) [Example 1] The ratio of THF to ethylene oxide was 70.
Dimethylacetamide solution (40% by weight) of polyurethane consisting of a polyol ("Tetoxynol" manufactured by Sanyo Chemical Industries, Ltd.) which is a random copolymer having a molecular weight of 3300 and MDI and ethylene glycol.
90 g of a dimethylacetamide solution (40% by weight) of PVP (K = 30) manufactured by Kanto Chemical Co., Ltd. of 000 g was added, and stirred for 2 hours to prepare a sample solution. The obtained solution is discharged from a die into a nitrogen gas at a dry atmosphere temperature of 380 ° C,
540 when the speed ratio between the godet roller and the winder is 1.40
Dry spinning was performed at a speed of m / min to obtain a 20 dtex, monofilament yarn. The spinnability was good.

The yarn elongation, strength, stress relaxation, heat setting, PVP content, residual strain measured at −5 ° C. (SET
%) Are shown in Table 1.

[0094] A product having excellent elastic properties without settling even at a low temperature and excellent in extensibility and recovery was obtained.

[0095]

[Table 1]

Example 2 A dimethylacetamide solution (38% by weight) of polyurethane composed of polyol, MDI and ethylene glycol, which are a random copolymer having a ratio of THF / propylene oxide of 70/30 and a molecular weight of 3000, is ISP in 3000 g. N-butenyl-
2,4-di (1-butenyl) -2-pyrrolidone at 10%
86 g of dimethylacetamide solution (40% by weight) of copolymerized PVP (GANEX P-904) was added, and stirred for 2 hours to obtain a sample solution. The obtained solution was discharged from a die into a nitrogen gas at a drying atmosphere temperature of 380 ° C., and dry-spinning was performed at a speed of 540 m / min with a speed ratio of a godet roller and a winder of 1.40.
A 0 dtex, monofilament yarn was obtained. The spinnability was good.

The yarn elongation, strength, stress relaxation, heat setting, PVP content, residual strain measured at −5 ° C. (SET
%) Are also shown in Table 1.

[0098] A product having excellent elastic properties without settling even at a low temperature and excellent in extensibility and recovery was obtained. Example 3 BASF PVP ("Rubiscol" K30 Special Grade, hereinafter abbreviated as K30SP) obtained by polymerizing 3,000 g of the same polyurethane dimethylacetamide solution (39% by weight) as in Example 2 using isopropyl alcohol as a polymerization solvent. 176 g of a dimethylacetamide solution (40% by weight) was added and stirred for 2 hours to obtain a sample solution. The obtained solution is discharged from a die into a nitrogen gas having a dry atmosphere temperature of 380 ° C., and is subjected to dry spinning at a speed of 540 m / min with a speed ratio of a godet roller and a winder of 1.40, whereby 20 dtex,
A monofilament yarn was obtained. The spinnability was good.

The yarn elongation, strength, stress relaxation, heat setting, PVP content, residual strain measured at -5 ° C. (SET
%) Are also shown in Table 1.

[0100] A product having excellent elastic properties without settling even at a low temperature and excellent in extensibility and recovery was obtained. [Example 4] The same polyurethane solution 300 as in Example 1
0 g of commercially available polyvinylidene fluoride (number average molecular weight 48
240 g of a dimethylacetamide solution (10% by weight) having a melt viscosity of 12,000 poise) and stirring for 2 hours were used as a sample solution.

The obtained solution was dried at a temperature of 380 ° C.
And spin-dry spinning at a speed of 540 m / min with a speed ratio of a godet roller and a winder of 1.40, thereby obtaining a 20 dtex, monofilament yarn. The spinnability was good.

The yarn elongation, strength, stress relaxation, heat setting, chemical resistance, polyvinylidene fluoride content and -5%
Table 1 also shows the residual strain (SET%) measured at ° C.

The chemical resistance of this yarn was 84%.

Excellent elastic extensibility without settling even at low temperatures,
A product excellent in recoverability and chemical resistance was obtained. Comparative Example 1 Dry spinning of a polyurethane dimethylacetamide solution (39% by weight) comprising PTMG, MDI and ethylene glycol having a molecular weight of 2100 at a speed of 540 m / min with a speed ratio of a godet roller and a winder of 1.40. As a result, a 20 dtex, monofilament yarn was obtained. Elongation, strength, stress relaxation, heat setting and residual strain (SET%) of this yarn measured at -5 ° C
Are also shown in Table 1.

The chemical resistance of this yarn was 56%.

[0106]

According to the present invention, the elastic properties are not impaired even at a low temperature, the material has excellent low-temperature properties without settling, has good stretchability and recoverability, and has good heat setting properties. Polyurethane elastic fiber can be obtained.

When the polyurethane elastic fiber of the present invention is used for clothes and the like, it is possible to obtain a fiber having excellent detachability, fit, appearance quality, wearability, wearing feeling, chemical resistance and the like. Because of these excellent properties, in addition to use alone, in combination with various fibers, for example, socks, stockings, circular knit, tricot, swimwear,
Ski trousers, work clothes, fireworks clothes, clothes, golf pants,
Wet suits, brassiere, girdle, gloves, socks and other textile products, tightening materials for sanitary products such as paper diapers, etc. It can be applied to various uses such as a printer, a copy cleaner, and a gasket.

Claims (12)

[Claims] 1. A polyurethane comprising a polyol, a diisocyanate and a diol as main components, wherein the polyol contains a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide, and is soluble in an organic solvent. A polyurethane elastic fiber comprising a polymer material. 2. The polyurethane elastic fiber according to claim 1, wherein the polymer substance soluble in the organic solvent is polyvinylpyrrolidone and / or a copolymer thereof. 3. The polyurethane elastic fiber according to claim 2, wherein the K value of polyvinylpyrrolidone and / or a copolymer thereof is 20 or more and 70 or less. 4. The polyurethane elastic fiber according to claim 1, wherein the polymer substance soluble in the organic solvent is polyvinylidene fluoride. 5. A polyvinylidene fluoride having a number average molecular weight of 3
The polyurethane elastic fiber according to claim 4, wherein the number is from 00 to 300,000. 6. The polyurethane elastic fiber according to claim 4, wherein the polyvinylidene fluoride has a melt viscosity at 240 ° C. of not less than 5,000 poise and not more than 50,000 poise. 7. The polyurethane elastic fiber according to claim 1, wherein the molar fraction of ethylene oxide units and / or propylene oxide units is in the range of 5 to 90%. 8. A polyol having a molecular weight of 1,000 or more and 60 or more.
The polyurethane elastic fiber according to any one of claims 1 to 7, which is in the range of 00 or less. 9. Polyurethane containing a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide, a diisocyanate and a diol as main components, and a polyurethane containing a polymer substance soluble in an organic solvent as a solute. A method for producing a polyurethane elastic fiber, comprising spinning a polyurethane solution as described above. 10. The method for producing a polyurethane elastic fiber according to claim 9, wherein the polymer substance soluble in the organic solvent is polyvinylpyrrolidone and / or a copolymer thereof. 11. The method according to claim 9, wherein the polymer substance soluble in the organic solvent is polyvinylidene fluoride. 12. The method for producing a polyurethane elastic fiber according to claim 9, wherein the spinning method is a dry method.