JP2004131861A - Method for producing polyurethane elastic fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyurethane elastic fiber which can be produced in reduced fiber breaking frequency, is not permanently settled even at low temperature, and has excellent elastic characteristics, good extensibility and good recoverability. <P>SOLUTION: This method for producing the polyurethane elastic fiber, comprising preliminarily preparing a polyurethane composed from a polyol, a diisocyanate and a chain extender as main components and then spinning the polyurethane, is characterized in that the content of an acidic catalyst left in the polyol is ≤2ppm. <P>COPYRIGHT: (C)2004,JPO

Description

【００６３】
［実施例２］
硼素含有量が１．７ｐｐｍであるポリオールを用いたこと以外は実施例１と同様の方法でポリマー溶液および糸を得た。
【００６４】
このポリマー溶液の粘度特性、糸の伸度、強度、応力緩和、−５℃で測定した残留歪みを表１に示す。
【００６５】
［比較例１］
硼素含有量が４．０ｐｐｍであるポリオールを用いたこと以外は実施例１と同様の方法でポリマー溶液および糸を得た。
【００６６】
このポリマー溶液の粘度特性、糸の伸度、強度、応力緩和、−５℃で測定した残留歪みを表１に示す。
【００６７】
実施例１，２では、紡糸可能な粘度のポリマー溶液が得られ、かつ、紡糸時に糸切れ等のトラブルは起こらなかったのに対し、比較例１のポリマー溶液はゲル化し、粘度測定不能となり、紡糸時も口金からポリマーが吐出せず、原糸を得ることができなかった。
【００６８】
【発明の効果】
本発明によれば、ポリマーを重合する際の粘度が不安定し、製造工程での糸切れ頻度が少なく、低温でもヘタリのない優れた弾性特性、良好な伸長性と回復性を有するポリウレタン弾性繊維を製造することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a polyurethane elastic fiber which has a low thread breakage frequency in a production process, has excellent elastic properties without settling even at a low temperature, and has good elongation and recovery properties.
[0002]
[Prior art]
Elastic fibers are widely used for elastic clothing such as legwear, innerwear, and sportswear, and for industrial materials because of their excellent elastic properties.
[0003]
As such elastic fibers, polyurethane elastic fibers are used, and a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran, and a polyurethane polymer composed of an organic diisocyanate and a diamine compound are known (for example, see Patent Documents 1 to 3). Also, a technique of spinning a polyurethane polymer comprising a copolymer of tetrahydrofuran and ethylene oxide, an organic diisocyanate and a diamine compound is known (for example, see Patent Document 4).
[0004]
[Patent Document 1]
JP-A-63-235320 (pages 2 to 3).
[0005]
[Patent Document 2]
JP-A-5-239177 (pages 2 to 3).
[0006]
[Patent Document 3]
JP-A-2-19511 (pages 3 to 6).
[0007]
[Patent Document 4]
JP-A-2001-226823 (pages 2 to 5).
[0008]
[Problems to be solved by the invention]
However, in the above-mentioned conventional technology, the viscosity is unstable when polymerizing the polymer, and the viscosity becomes higher than the proper spinning viscosity, so that yarn breakage frequently occurs in the spinning process, and furthermore, the spinning becomes impossible. Was.
[0009]
An object of the present invention is to provide a method for producing a polyurethane elastic fiber which has a low thread breakage frequency in the production process, has excellent elastic properties without settling even at a low temperature, and has good elongation and recovery properties.
[0010]
[Means for Solving the Problems]
The method for producing a polyurethane elastic fiber of the present invention employs the following means in order to solve the above problems.
[0011]
That is, the main component is a polyurethane composed of a polyol, a diisocyanate and a chain extender in advance, and when the polyurethane is spun to obtain a polyurethane elastic fiber, the acidic catalyst remaining in the polyol is 2 ppm or less. This is a method for producing a polyurethane elastic fiber.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the method for producing a polyurethane elastic fiber of the present invention will be described in more detail.
[0013]
The polyurethane elastic fiber of the present invention is a polyurethane whose main component is a polyol, a diisocyanate and a chain extender, but trifunctional or higher polyfunctional glycols and isocyanates are used as long as the effects of the present invention are not impaired. It does not matter.
[0014]
In the present invention, the polyurethane may be obtained by a melt polymerization method or a solution polymerization method. However, it is preferable to polymerize in a solution from the viewpoint that the generation of foreign substances such as gel in the polyurethane is small and the reaction is performed efficiently.
[0015]
Here, typical structural units constituting the polyurethane in the present invention will be described.
[0016]
The polyol used in the present invention has excellent cold resistance and high elongation, and from the viewpoint of obtaining one having high recoverability, tetrahydrofuran (hereinafter abbreviated as THF), ethylene oxide and / or propylene oxide, That is, it is preferable to use a so-called random copolymer in which THF and ethylene oxide, or THF and propylene oxide, or THF, ethylene oxide and propylene oxide are randomly arranged.
[0017]
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 physical properties at the time of water absorption are reduced.
[0018]
That is, the polyol used in the present invention can also be expressed as a copoly (alkylene ether) glycol selected from poly (tetramethylene-co-ethylene ether) glycol and poly (tetramethylene-co-1,2-propylene ether) glycol. .
[0019]
In such poly (tetramethylene-co-ethylene ether) glycol, the content of ethylene ether is preferably from 15 to 37 mol%, more preferably from 20 to 35 mol%, based on all alkylene ethers.
[0020]
In the poly (tetramethylene-co-1,2-propylene ether) glycol, it is preferable that 1,2-propylene ether is contained in an amount of 15 to 30 mol% based on all alkylene ethers.
[0021]
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 mixture mixed with another polyol. You may.
[0022]
As other polyols, poly (1,4-tetramethylene glycol) (hereinafter, abbreviated as PTMG) is used from the viewpoint of obtaining a polyol having excellent cold resistance, high elongation, and high recovery. Diols having a neopentyl group in the main chain thereof disclosed in Japanese Patent No. 2615131, polycarbonate diols disclosed in JP-A-2-289616, etc., and esters disclosed in JP-A-5-98511 and the like. It is preferable to use a system diol, 1,4-butanediol, 1,6-hexanediol, polycaprolactone diol, 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.
[0023]
In the present invention, the molar fraction of ethylene oxide and / or propylene oxide units is preferably in the range of 5 to 90%.
[0024]
The weight average molecular weight of the polyol used in the present invention is preferably in the range of 1000 or more and 6000 or less from the viewpoints of elongation, strength, heat resistance, and the like when formed into yarn. More preferably, it is in the range of 1300 or more and 4500 or less. By using a polyol having a molecular weight in this range, an elastic yarn having well-balanced mechanical properties can be obtained.
[0025]
In the polyol used in the present invention, the residual amount of the acidic catalyst used in producing the polyol is preferably 2 ppm or less. The residual amount may be 0 ppm. If it exceeds this range, the viscosity of the obtained polymer solution becomes high, and the yarn breaks frequently in the spinning process or is not spun from the die, so that the original yarn cannot be obtained.
[0026]
The acidic catalyst remaining in the polyol preferably contains at least one element selected from the group consisting of iron, phosphorus, zinc, titanium, zirconium, and beryllium.
[0027]
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 Isocyanate-2-[(4-isocyanate-phenyl) methyl] benzene, 1,1′-methylenebis (4-isocyanatocyclohexane), 4-methyl-1,3-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate Aromatic diisocyanates such as MDI), 2,4-tolylene diisocyanate (hereinafter abbreviated as TDI), 1,4-diisocyanate benzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate are particularly heat-resistant and Strong Preferred have for the synthesis of polyurethane.
[0028]
Further, as alicyclic diisocyanates, for example, methylene bis (cyclohexyl isocyanate) (hereinafter abbreviated as H ₁₂ MDI), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate , Hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, octahydro-1,5-naphthalenediisocyanate and the like are preferred. Aliphatic diisocyanates are preferably used particularly for suppressing yellowing of polyurethane yarns.
[0029]
These diisocyanates may be used alone or in combination of two or more.
[0030]
The molar ratio of the diisocyanate is preferably in the range of 1.2 or more and 2.3 or less with respect to the polyol 1 from the viewpoint of the strength characteristics of the obtained polyurethane elastic fiber.
[0031]
Next, it is desirable to use a low molecular weight diamine and / or a low molecular weight diol as the chain extender used in the present invention. Further, instead of the low molecular weight diamine or the low molecular weight diol, a compound having a hydroxyl group and an amino group such as ethanolamine in the molecule may be used alone or in combination.
[0032]
Examples of the low molecular weight diamine include hydrazine, ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2-methyl-1,5-pentanediamine, 1,2-diaminobutane, and 1,3-diaminobutane , 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,2-dimethyl-1,3-diaminopropane, 1,3-diamino-2,2-dimethylbutane, 2,4-diamino -1-methylcyclohexane, 1,3-pentanediamine, 1,3-cyclohexanediamine, bis (4-aminophenyl) phosphine oxide, hexamethylenediamine, 1,3-cyclohexyldiamine, hexahydrometaphenylenediamine, 2-methyl Pentamethylenediamine, bis (4-aminophenyl) phosph Preferably used, such as down-oxide. In particular, from the viewpoint of obtaining a material excellent in elongation and elastic recovery, it is preferable to use ethylenediamine.
[0033]
Examples of low molecular weight diols include, but are not limited to, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-propylene glycol, 3-methyl-1,5-pentanediol, and 2,2-dimethyl- 1,3-trimethylenediol, 2,2,4-trimethyl-1,5-pentanediol, 2-methyl-2-ethyl-1,3-propanediol, bishydroxyethoxybenzene, bishydroxyethylene terephthalate, or the like is used. Is preferred. In particular, from the viewpoint of obtaining a polyurethane having high heat resistance and high strength, it is preferable to use etherene glycol, 1,3-propanediol, and 1,4-butanediol.
[0034]
It is also preferable to add a triamine compound capable of forming a crosslinked structure to these chain extenders, such as diethylenetriamine, to such an extent that the effect is not lost.
[0035]
Such a polyurethane can be obtained by a so-called melt polymerization method that can use only the above-mentioned raw materials, or, for example, the above-mentioned raw materials can be used in a solvent containing DMAC, DMF, DMSO, NMP or the like as a main component. It can also be obtained by a so-called solution polymerization method.
[0036]
In the case of the solution polymerization method, for example, the so-called one-shot method in which each raw material is charged and dissolved in such a solvent and heated to an appropriate temperature to cause a reaction with polyurethane urea, or a polyol and MDI are first melt-reacted, Thereafter, a method in which the reactant is dissolved in a solvent and reacted with the above-mentioned chain extender to obtain a polyurethane can be employed as a particularly preferable method.
[0037]
In synthesizing such a polyurethane, one kind or a mixture of two or more kinds of amine catalysts and organometallic catalysts may be used. As typical examples thereof, amine catalysts include, for example, N, N-dimethylcyclohexylamine, N, N-dimethylbenzylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethyl-1,3-propanediamine, N, N, N ', N'-tetramethylhexanediamine, bis-2-dimethylamino Ethyl 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-dimethylaminohexanol, triethanolamine and the like can be preferably used. As the organic metal catalyst, tin octoate, dibutyl tin dilaurate, dibutyl lead octoate and the like can be preferably used.
[0038]
Further, in the present invention, it is preferable to use a chain terminator in order to control the molecular weight of the polyurethane and the viscosity of the polyurethane.
[0039]
As such a chain terminator, n-butanol, diethylamine, cyclohexylamine, n-hexylamine and the like are preferable.
[0040]
Usually, the chain terminator is preferably used in a mixture with a chain extender.
[0041]
Also, small amounts of trifunctional substances such as diethylenetriamine and glycerol can be used to control polymer viscosity.
[0042]
In the case of solution polymerization, the concentration of the polyurethane solution thus obtained is not particularly limited, but is usually preferably in the range of 30% by weight or more and 80% by weight or less.
[0043]
In the present invention, various additives such as an ultraviolet absorber, an antioxidant, and a gas-resistant stabilizer such as so-called BHT and "Sumilyzer" GA-80 manufactured by Sumitomo Chemical Co., Ltd. are used in the polyurethane. Hindered phenolic drugs, various "tinuvins" and other benzotriazole drugs, Sumitomo Chemical Co., Ltd. "Sumilyzer" P-16 and other phosphorus drugs, and various "tinuvins" Hindered amines, inorganic pigments such as titanium oxide, zinc oxide and carbon black, metal soaps such as magnesium stearate, and disinfectants and deodorants containing silver, zinc, and compounds thereof. And lubricants such as silicone and mineral oil, barium sulfate, cerium oxide, betaine and phosphoric acid. It is preferable to add various kinds of antistatic agents to fit. It is also preferred that these additives have been reacted with the 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., a thermal oxidation stabilizer such as manufactured by Sumitomo Chemical Co., Ltd. It is preferable to use "Sumilyzer" GA-80, a light stabilizer such as "Sumisorb" 300 # 622 manufactured by Sumitomo Chemical Co., Ltd. Any method can be adopted as a method for adding the additive to the polyurethane. As a typical method, in the case of melt polymerization, it is preferable to add in a heated and molten state using an extruder or the like, and in the case of solution polymerization, it is preferable to employ a method using a static mixer, a method using stirring, or the like. In particular, in the case of solution polymerization, since the additive can be uniformly added to the polyurethane solution if it is a solution, it is preferable to add the additive in a solution. .
[0044]
In the present invention, polyurethane elastic fiber is obtained by spinning polyurethane. The spinning method may be any of a wet method, a dry method, and a melting method.
[0045]
From the viewpoint of increasing the spinning speed, spinning is preferably performed by a dry method. In dry spinning, a gas supply unit is provided at at least two places, 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 preferably set to 60 ° C. or less from the viewpoint of eliminating yarn unevenness.
[0046]
In spinning, the speed ratio between the godet roller and the winder is preferably determined according to the purpose of use of the yarn.
[0047]
In the present invention, it is preferable that the speed ratio between the godet roller and the winder be 1.1 to 1.8 and wound.
[0048]
The spinning speed is preferably 300 m / min or more and 800 m / min or less.
[0049]
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.
[0050]
【Example】
The present invention will be described in more detail by way of examples. However, the present invention is not limited by these examples.
[0051]
The method of quantifying stress relaxation, strength, elongation, residual strain, and heat resistance in the present invention will be described.
[Stress relaxation, strength, elongation, residual strain]
The stress relaxation, strength, elongation, and residual strain were obtained by subjecting the polyurethane yarn to a tensile test using an Instron 4502 tensile tester.
[0052]
The stress relaxation, strength, and elongation were measured at 22 ° C, and the residual strain was measured at -5 ° C.
[0053]
These are defined below.
[0054]
A 5 cm (L1) sample was subjected to 300% elongation five times at a tensile speed of 50 cm / min. The stress at this time was defined as (G1).
[0055]
The length was then held for 30 seconds. The stress after holding for 30 seconds was defined as (G2).
[0056]
The sample length when the stress was set to 0 was set to (L2).
[0057]
The polyurethane yarn was further stretched for the sixth time until it was cut.
[0058]
The stress at break was (G3) and the sample length at break was (L3).
[0059]
Hereinafter, the above characteristics were obtained by the following equation.
[0060]
Strength = (G3)
Stress relaxation (%) = 100 × ((G1) − (G2)) / (G1)
Residual strain (%) = 100 × ((L2) − (L1)) / (L1)
Elongation (%) = 100 × ((L3) − (L1)) / (L1)
[Example 1]
2900 g of a polyol (“Tetroxynol AS-200S” manufactured by Sanyo Chemical Industries, Ltd.) which is a random copolymer having a boron content of 0.6 ppm, a ratio of THF to ethylene oxide of 7: 3 and a molecular weight of 1951, and After reacting 595.8 g of MDI under the condition of no solvent, it was dissolved in 6602 g of dimethylacetamide, and 53.7 g of ethylenediamine and 5.45 g of diethylamine were added to obtain a 35% by weight polyurethane solution. To this polyurethane solution, 35 g of "Sumilyzer" (registered trademark) GA80 manufactured by Sumitomo Chemical Co., Ltd., 35 g of a reaction product of t-butyldiethanolamine and methylene-bis- (4-cyclohexylisocyanate), and 175 g of titanium oxide were added. Thus, a sample solution was prepared. The resulting solution was dry-spun at a speed of 500 m / min to obtain a yarn of 470 decitex and 56 filaments.
[0061]
Table 1 shows the viscosity, elongation, strength, stress relaxation and residual strain of the polymer solution measured at -5 ° C.
[0062]
[Table 1]

[0063]
[Example 2]
A polymer solution and a yarn were obtained in the same manner as in Example 1 except that a polyol having a boron content of 1.7 ppm was used.
[0064]
Table 1 shows the viscosity characteristics, elongation, strength, stress relaxation, and residual strain of the polymer solution measured at -5 ° C.
[0065]
[Comparative Example 1]
A polymer solution and a yarn were obtained in the same manner as in Example 1, except that a polyol having a boron content of 4.0 ppm was used.
[0066]
Table 1 shows the viscosity characteristics, elongation, strength, stress relaxation, and residual strain of the polymer solution measured at -5 ° C.
[0067]
In Examples 1 and 2, a polymer solution having a viscosity that can be spun was obtained, and troubles such as thread breakage did not occur during spinning. On the other hand, the polymer solution of Comparative Example 1 gelled and the viscosity could not be measured. During spinning, the polymer was not discharged from the spinneret, and the original yarn could not be obtained.
[0068]
【The invention's effect】
According to the present invention, a polyurethane elastic fiber having an unstable viscosity at the time of polymerizing a polymer, a low frequency of thread breakage in a manufacturing process, excellent elastic properties without settling even at a low temperature, good elongation and recovery properties. Can be manufactured.

Claims (4)

Polyurethane comprising a polyol, a diisocyanate, and a chain extender whose main components are prepared in advance, and when the polyurethane is spun to obtain a polyurethane elastic fiber, the acidic catalyst remaining in the polyol is 2 ppm or less. Fiber manufacturing method. The method for producing a polyurethane elastic fiber according to claim 1, wherein the polyol is a random copolymer of tetrahydrofuran and ethylene oxide and / or propylene oxide. The polyurethane elastic fiber according to claim 1 or 2, wherein the acidic catalyst remaining in the polyol contains at least one element selected from the group consisting of iron, phosphorus, zinc, titanium, zirconium, and beryllium. Manufacturing method. The method for producing a polyurethane elastic fiber according to any one of claims 1 to 3, wherein the chain extender comprises a diamine and / or a diol.