HK1024252B - Thermoplastic polyurethanes, polyurethane elastic fibers therefrom, and method for producing the fibers - Google Patents
Thermoplastic polyurethanes, polyurethane elastic fibers therefrom, and method for producing the fibers Download PDFInfo
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- HK1024252B HK1024252B HK00103396.4A HK00103396A HK1024252B HK 1024252 B HK1024252 B HK 1024252B HK 00103396 A HK00103396 A HK 00103396A HK 1024252 B HK1024252 B HK 1024252B
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Description
The present invention relates to thermoplastic polyurethanes, polyurethane elastic fibers made therefrom, and methods of making the fibers. The polyurethane fiber obtained from the thermoplastic polyurethane of the present invention has excellent heat resistance, excellent hot water resistance and excellent elastic recovery.
Known methods for producing polyurethane elastic fibers are dry spinning, wet spinning, melt spinning, and the like. Among these methods, the polyurethane elastic fiber obtained by the melt spinning method has excellent thermosetting property, abrasion resistance and light transmittance, and the production cost thereof is low. Therefore, recently, the consumption of such fibers has been greatly increased. However, the polyurethane fiber obtained by the melt spinning method is difficult to form a hard segment as compared with the polyurethane fiber obtained by the dry spinning method, and therefore, both the heat resistance and hot water resistance are unsatisfactory.
For these reasons, various methods for improving the heat resistance and hot water resistance of melt-spun polyurethane elastic fibers have been proposed so far. One conventional method is to form an intermolecular crosslinked structure in the polyurethane constituting the fiber. For example, JP-A-48-58095, JP-B-50-10630 and JP-A-6-294012 describe ｃA method of forming ｃA crosslinked structure in the hard segment portion of polyurethane by using ｃA trifunctional or higher-functional polyfunctional chain extender such as trimethylolpropane. However, the heat resistance of conventional polyurethanes having such a crosslinked structure formed in the hard segment is still unsatisfactory, and therefore, the heat resistance of polyurethane elastic fibers made of such polyurethanes is also unsatisfactory.
In addition to the above-mentioned conventional methods, another method has been proposed for obtaining a polyurethane elastic fiber having a reduced residual strain and an increased dynamic elastic resilience by reacting a hydroxyl polyester (prepared from a reaction of a diol having a secondary hydroxyl group and a trifunctional or higher-functional polyol with a dicarboxylic acid) and a chain extender with an organic diisocyanate and then preparing the resulting polyurethane into a polyurethane elastic fiber by melt spinning (see JP-B-42-3958). However, the heat resistance of the polyurethane elastic fiber obtained by this method is still poor, and this method cannot achieve the object of obtaining a polyurethane elastic fiber having excellent heat resistance. Furthermore, we, the present inventors, having actually produced polyurethane and polyurethane elastic fibers according to the method in the examples described in JP-B-42-3958, have found that the fibers are not only inferior in heat resistance but also inferior in hot water resistance and other properties.
JP-B-42-5251 proposes a method for producing polyurethane elastic fibers by preparing polyurethane from a polyol having more than two hydroxyl functional groups and then spinning by a wet chemical spinning method. However, the uniformity of the fiber obtained by the wet chemical spinning method among the proposed methods is poor and the abrasion resistance is also poor. On the other hand, JP-A-59-179513 and 63-159519 describe polyurethanes prepared from prepolymers containing soft segments prepared from ｃA mixture of polyester diols and polyether diols, which polyurethanes have excellent solution stability during spinning thereof. However, the polyurethanes described therein are unsatisfactory with respect to heat resistance and hot water resistance.
In that case, JP-A-3-220311 describes polyurethanes prepared from polyester diols (prepared by reaction of ｃA diol containing 3-methyl-1, 5-pentanediol with an aliphatic dicarboxylic acid component having 6 to 12 carbon atoms), organic diisocyanates and chain extenders, and fibers made from the resulting polyurethanes. The polyurethane elastic fiber is said to have excellent chlorine resistance, water resistance, mold resistance, elastic recovery, heat resistance, hot water resistance and elongation. Further, JP-A-9-49120 describes polyurethane elastic fibers made of polyurethane prepared from ｃA polyester diol, an organic diisocyanate and ｃA chain extender. It is said that when the composition of the starting components of the polyurethane, such as the polyester polyol, is well defined, the uniformity of the polyurethane fiber can be improved while maintaining the excellent properties of the fiber as described above. The heat resistance and hot water resistance of those polyurethane elastic fibers can be improved to some extent. However, there is still a need to further improve the properties of polyurethane elastic fibers.
It is an object of the present invention to provide a thermoplastic polyurethane having excellent elastic recovery and elongation properties, particularly excellent heat resistance and hot water resistance, to provide a polyurethane elastic fiber made from the polyurethane, and to provide a method for manufacturing the fiber.
Specifically, the present invention provides thermoplastic polyurethanes prepared by the reaction of:
[1] a polyol composition (A) consisting essentially of a polyester polyol (A-1) and a polyether polyol (A-2), the polyester polyol having a crystallization enthalpy of at most 70J/g, a number average molecular weight of 1000 to 5000, the polyether polyol having a number average molecular weight of 500 to 2500, the molar ratio of the polyester polyol to the polyether polyol being 5/95 to 95/5, the polyol composition having an average number f of hydroxyl functional groups which can be represented by the following formula (I):
f ═ all hydroxyl groups in the polyol making up the polyol composition }/{ making up the polyol composition
The number of molecules of all polyols of the compound } (I), f is between 2.006 and 2.100,
[2] an organic diisocyanate (B), and
[3] a chain extender (C) in a proportion satisfying the following formula (II):
1.00. ltoreq. B/(a + C). ltoreq.1.10 (II) wherein a represents the number of moles of all the polyols constituting the polyol composition (A), B represents the number of moles of the organic diisocyanate (B), C represents the number of moles of the chain extender (C),
the polyether polyol (A-2) is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polymethyltetramethylene glycol; and
the organic diisocyanate (B) is selected from the group consisting of 4, 4 '-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, naphthalene-1, 5-diisocyanate, 3' -dichloro-4, 4 '-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate.
The present invention also provides a polyurethane elastic fiber comprising the above thermoplastic polyurethane.
The present invention also provides a process for producing a polyurethane elastic fiber, which comprises melt-spinning the above thermoplastic polyurethane, or preparing a thermoplastic polyurethane by reacting (A), (B) and (C) in the above predetermined ratio, and melt-spinning it.
The thermoplastic polyurethane of the present invention and the polyurethane elastic fiber containing the same have various excellent properties including spinning stability, heat resistance, hot water resistance, elastic recovery, elongation and uniformity, and have many applications in various fields due to their excellent characteristics. According to the production method of the present invention, a high-quality polyurethane elastic fiber having the above-mentioned various excellent characteristics can be produced smoothly from the thermoplastic polyurethane of the present invention by favorable processing characteristics. In particular, in this method, the thermoplastic polyurethane can be stably spun while suppressing the increase in pressure in the spinneret assembly.
The present invention is described in detail below.
The thermoplastic polyurethane of the present invention is prepared by reacting a polyol composition (A) consisting essentially of the above-mentioned polyester polyol (A-1) and polyether polyol (A-2) with an organic diisocyanate (B) and a chain extender (C) in a ratio satisfying the following formula (II):
1.00. ltoreq. B/(a + C). ltoreq.1.10 (II) wherein a represents the number of moles of all the polyols constituting the polyol composition (A), B represents the number of moles of the organic diisocyanate (B), and C represents the number of moles of the chain extender (C). If the ratio b/(a + c) is less than 1.00, the thermoplastic polyurethane to be produced will have a relatively low molecular weight, and thus the polyurethane elastic fiber obtained therefrom will not have excellent heat resistance and excellent hot water resistance. On the other hand, if the ratio b/(a + c) is greater than 1.10, the spinning stability in the production of polyurethane elastic fiber will be poor, and thus the produced polyurethane elastic fiber will not be uniform. To further improve the spinning stability, heat resistance and hot water resistance of the thermoplastic polyurethane and polyurethane elastic fiber obtained from the polyurethane, the ratio b/(a + c) needs to be between 1.00 and 1.07.
The number average molecular weight of the polyester polyol (A-1) constituting the thermoplastic polyurethane of the present invention is from 1000 to 5000. If the number average molecular weight of the polyester polyol (A-1) is less than 1000, the thermoplastic polyurethane prepared and the polyurethane elastic fiber obtained therefrom do not have excellent heat resistance and excellent hot water resistance. On the other hand, if the number average molecular weight of the polyester polyol (A-1) is more than 5000, the spinning stability in the production of polyurethane elastic fiber will be poor, and thus the produced polyurethane elastic fiber will not be uniform. Preferably, the number average molecular weight of the polyester polyol (A-1) is between 1500 and 3500. The number average molecular weight of the polyester polyol (A-1) and the number average molecular weight of the polyether polyol (A-2), which will be described in detail hereinafter, are calculated on the basis of the hydroxyl value of those polymers, which is measured in accordance with JIS K-1577.
The polyester polyol (A-1) constituting the thermoplastic polyurethane of the present invention has a crystallization enthalpy (. DELTA.H) of at most 70J/g. If the crystallization enthalpy (. DELTA.H) of the polyester polyol (A-1) is more than 70J/g, the elongation and elastic recovery of the thermoplastic polyurethane prepared and the polyurethane elastic fiber obtained therefrom are greatly reduced. The crystallization enthalpy (. DELTA.H) of the present invention is preferably not less than 0J/g. The crystallization enthalpy (. DELTA.H) of the polyester polyol (A-1) mentioned herein can be measured by a differential scanning calorimeter. Specifically, it shows data measured according to the method described in the examples described below.
The polyether polyol (A-2) constituting the thermoplastic polyurethane of the present invention has a number average molecular weight of 500 to 2500. If the number average molecular weight of the polyether polyol (A-2) is less than 500, the thermoplastic polyurethane prepared and the polyurethane elastic fiber obtained therefrom do not have excellent heat resistance and excellent hot water resistance. On the other hand, if the number average molecular weight of the polyether polyol (A-2) is more than 2500, not only does the polymerization reaction for preparing the thermoplastic polyurethane hardly proceed, but also the spinning stability in the process of producing the polyurethane elastic fiber is poor, and thus the produced polyurethane elastic fiber is not uniform. Preferably, the polyether polyol (A-2) has a number average molecular weight of 700 to 2300.
The polyol composition (A) constituting the thermoplastic polyurethane of the present invention is mainly composed of a polyester polyol (A-1) and a polyether polyol (A-2). In view of the heat resistance and hot water resistance of the thermoplastic polyurethane produced and the polyurethane elastic fiber obtained therefrom, the proportion of the components (A-1) and (A-2) in (A) needs to be at least 80 mol%, more preferably at least 90 mol%, based on the moles of all the polyols constituting the polyol composition (A).
The molar ratio (A-1)/(A-2) of the polyester polyol (A-1) to the polyether polyol (A-2) is preferably between 5/95 and 95/5, more preferably between 10/90 and 90/10. If the molar ratio is less than 5/95, spinning stability during the production of the polyurethane elastic fiber may be poor and, in addition, elongation of the fiber may be low. On the other hand, if the molar ratio is more than 95/5, the thermoplastic polyurethane prepared and the polyurethane elastic fiber obtained therefrom will have little excellent heat resistance and excellent hot water resistance.
The polyol composition (A) constituting the thermoplastic polyurethane of the invention is defined in that the average number f of hydroxyl functional groups therein is between 2.006 and 2.100. The average f can be represented by the following formula (I):
f ═ all hydroxyl groups in the polyol making up the polyol composition }/{ making up the polyol composition
Number of molecules of all polyols of the compound } (I).
As is evident from formula (I), the average number of hydroxyl functional groups, f, in (a) represents the average number of hydroxyl groups per polyol molecule in the polyol composition (a).
If the average number f of the hydroxyl functional groups in the polyol composition (A) is less than 2.006, the molecular weight of the resulting thermoplastic polyurethane will not be high, and thus not only will the thermoplastic polyurethane and the polyurethane elastic fiber obtained therefrom have little excellent heat resistance and excellent hot water resistance, but also the spinning stability in the production of the polyurethane elastic fiber will be poor. As a result, the manufactured polyurethane elastic fiber may not be uniform. This tendency increases as the ratio of the polyether polyol (A-2) to the polyester polyol (A-1) increases.
On the other hand, if the average number f of hydroxyl functional groups in (A) is more than 2.100, the resulting thermoplastic polyurethane will have poor heat resistance and hot water resistance. In addition, to do so, the spinning temperature of the thermoplastic polyurethane must be high. However, when spun at high temperature, the thermoplastic polyurethane is pyrolyzed to produce a thermal degradation product, and thus the spinning stability thereof is deteriorated.
In view of the heat resistance and hot water resistance of the resulting thermoplastic polyurethane, it is preferable that the average number of hydroxyl functional groups in the polyol composition (a) is between 2.010 and 2.080.
The polyester polyol (A-1) used in the present invention is prepared by reacting a dicarboxylic acid component with a polyol component containing a diol, if necessary, a small amount of a trifunctional or higher-functional polyfunctional alcohol. In the polycondensation reaction to produce the polyester polyol (A-1), the ratio of the dicarboxylic acid component to the polyol component is specified so that the average number f of hydroxyl functional groups in the polyol composition (A) containing a predetermined amount of the polyester polyol (A-1) must be within the specified range of 2.006 to 2.100, and the number average molecular weight of the polyester polyol (A-1) is 1000 to 5000.
As defined hereinabove, in order that the polyester polyol (A-1) obtained by the polycondensation reaction has a crystallization enthalpy Δ H of at least 70J/g, it is preferred that a part or all of the dicarboxylic acid component is a branched non-cyclic dicarboxylic acid and/or a part or all of the polyol component is a branched non-cyclic primary diol. With respect to the proportion of the branched non-cyclic dicarboxylic acid and/or the branched non-cyclic primary diol under the preferred conditions, it is desirable that the moles of both the branched non-cyclic dicarboxylic acid and the branched non-cyclic primary diol are at least 10 mole%, more preferably at least 30 mole%, even more preferably at least 50 mole% and at most 100 mole%, the percentages being based on the moles of all the dicarboxylic acid component and the polyol component used to produce the polyester polyol (A-1).
If the moles of the branched non-cyclic dicarboxylic acid and the branched non-cyclic primary diol are less than 10 mole% based on the content of moles of all the dicarboxylic acid component and the polyol component used to form the polyester polyol (A-1), the crystallization enthalpy AH of the polyester polyol (A-1) may hardly reach not more than 70J/g, and as a result, the crystallization enthalpy AH of the polyester polyol (A-1) may be out of the range specified in the present invention. This causes that the thermoplastic polyurethane comprising a polyester polyol having a crystallization enthalpy exceeding the specified range is poor in both elongation and elastic recovery, heat resistance and hot water resistance, and even the polyurethane elastic fiber obtained from the polyurethane is poor in these properties. In terms of the content by moles based on all the dicarboxylic acid components and the polyol component, if the moles of the branched non-cyclic dicarboxylic acid and the branched non-cyclic primary diol are all at least 10 mole%, the resulting polyester polyol (A-1) can be satisfactory for use in the present invention anyway, wherein only the dicarboxylic acid component used for preparing the polyester polyol (A-1) contains a branched non-cyclic dicarboxylic acid but the polyol component does not contain a branched non-cyclic primary diol, or only the polyol component contains a branched non-cyclic primary diol but the dicarboxylic acid component does not contain a branched non-cyclic dicarboxylic acid, or the dicarboxylic acid component contains a branched non-cyclic dicarboxylic acid and the polyol component contains a branched non-cyclic primary diol.
When a branched non-cyclic dicarboxylic acid is preferably used for preparing the polyester polyol (A-1), a branched saturated aliphatic hydrocarbon chain having carboxyl groups at both ends of the chain, or a branched unsaturated aliphatic hydrocarbon chain and ester derivatives thereof, containing 5 to 14 carbon atoms, are preferred. Preferred examples of branched acyclic dicarboxylic acids of this type are 2-methylsuccinic acid, 3-methylglutaric acid, 2-methyladipic acid, 3-methylglutaric acid, 2-methylsuberic acid, 3, 7-dimethylsebacic acid, 3, 8-dimethylsebacic acid and ester derivatives thereof. One or more of these branched non-cyclic dicarboxylic acids may be used alone or in combination.
In the preparation of the polyester polyol (A-1), any other dicarboxylic acid including linear dicarboxylic acids and cyclic dicarboxylic acids may be used together with the branched non-cyclic dicarboxylic acid as described above, as necessary. Examples of the dicarboxylic acid are linear dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid and the like; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, tetrabromophthalic acid, and the like; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and the like; and ester derivatives thereof. One or more of these additional dicarboxylic acids may be used alone or in combination. To the extent that the polyester polyol (A-1) satisfies the requirements of the present invention, a small amount of trifunctional or higher-functional polyfunctional carboxylic acid such as trimellitic acid, pyromellitic acid or the like or an ester derivative thereof may be optionally used in the preparation of the polyester polyol.
When the branched non-cyclic primary diol is preferably used for preparing the polyester polyol (A-1), a branched saturated aliphatic hydrocarbon chain having a hydroxyl group at both ends of the chain, or a branched unsaturated aliphatic hydrocarbon chain, containing 4 to 10 carbon atoms, is preferred. Preferred examples of branched acyclic primary diols of this type are 2-methyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol, 2-methyl-1, 4-butanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol, and the like. Among them, 3-methyl-1, 5-pentanediol and 2-methyl-1, 8-octanediol are particularly preferable because they can further improve the heat resistance and hot water resistance of the thermoplastic polyurethane containing a diol and the polyurethane elastic fiber obtained from the polyurethane. One or more of these branched non-cyclic primary diols may be used alone or in combination.
In the preparation of the polyester polyol (A-1), any other diol including linear diols and cyclic diols as necessary may be used together with the branched non-cyclic primary diol described above. Examples of such diols are linear diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol, etc.; and alicyclic diols such as1, 4-cyclohexanedimethanol, and the like. One or more of these additional diols may be used alone or in combination.
As described above, in order that the average number f of the hydroxyl functional groups in the polyol composition (A) containing the polyester polyol (A-1) and the polyether polyol (A-2) in a predetermined ratio is within the specified range of 2.006 to 2.100, a small amount of trifunctional or higher-functional polyfunctional alcohol may preferably be used together with the above-mentioned diol in the preparation of the polyester polyol (A-1). Examples of polyfunctional alcohols of trifunctional or higher functionality for use with the diol are glycerol, trimethylolpropane, trimethylolbutane, trimethylolpentane, hexanetriol, pentaerythritol, diglycerol, and the like. One or more of these additional alcohols may be used alone or in combination. Among the additional alcohols, glycerol and trimethylolpropane are more preferred.
In the preparation reaction of the polyester polyol (A-1), the amounts of the reactants of the dicarboxylic acid component and the polyol component comprising a diol and a trifunctional or higher-functional polyfunctional alcohol must be controlled so that the average number of hydroxyl functional groups in the resulting polyester polyol (A-1) is within a predetermined range.
The polyester polyol (A-1) used for preparing the thermoplastic polyurethane of the present invention may be a single polyester polyol or a mixture of two or more polyester polyols. The polyester polyol (A-1), which is a single polyester polyol or a mixture of two or more polyester polyols without specific limitation, should satisfy the requirements of the present invention in any case.
The process for producing the polyester polyol (A-1) used in the present invention is not specifically defined. For example, it may be prepared by any of the well known polycondensation reactions involving esterification or transesterification reactions between the dicarboxylic acid component and the diol, trifunctional or higher-functional polyfunctional alcohol, and, if desired, trifunctional or higher-functional polyfunctional carboxylic acid component, as described above.
The polycondensation reaction for preparing the polyester polyol (A-1) may be carried out in the presence of a catalyst. Preferred catalysts are titanium catalysts and tin catalysts. Examples of usable titanium catalysts are titanic acid, titanium tetraalkoxide compounds, titanium acylates, titanium chelate compounds and the like. More specifically, there are tetraalkoxytitanium compounds such as tetraisopropyl titanate, tetra-n-butyl titanate, tetra-2-ethylhexyl titanate, tetrastearyl titanate, and the like; titanium acylates such as titanium polyhydroxystearate, titanium polyisopropoxycatearate and the like; titanium chelate compounds such as titanium acetoacetate, triethanolamine titanate, titanium ammonium lactate, titanium ethyl lactate, and the like. Examples of useful tin catalysts are dialkyltin diacetate, dialkyltin dilaurate, dialkyltin dimercaptocarboxylates, and the like. More specifically, there are dibutyltin diacetate, dibutyltin dilaurate, dibutyltin bis (ethoxybutyl-3-mercaptopropionate), and the like.
If a titanium catalyst is used, the amount thereof is not specifically defined but may vary depending on the reaction conditions. However, it is generally used in an amount of preferably about 0.1 to 50ppm, more preferably about 1 to 30ppm, based on the total weight of the reactants used in the preparation of the desired polyester polyol. If a tin catalyst is used, the amount thereof is not specifically defined, but may vary depending on the reaction conditions. However, it is generally used in an amount of preferably about 1 to 200ppm, more preferably about 5 to 100ppm, based on the total weight of the reactants used in the preparation of the desired polyester polyol.
When a polyester polyol is prepared in the presence of a titanium catalyst, it is desirable that the titanium catalyst remaining in the prepared polyester polyol is deactivated. If polyester polyols containing some non-deactivated titanium catalyst are used to prepare thermoplastic polyurethanes, the properties of the prepared thermoplastic polyurethanes and polyurethane elastic fibers obtained therefrom, such as heat resistance and hot water resistance, are generally poor.
For deactivating the titanium catalyst remaining in the polyester polyol, there can be used, for example, (1) a method of contacting the polyester polyol with water under heating, and (2) a method of treating the polyester polyol with a phosphorus-containing compound such as phosphoric acid, phosphate, phosphorous acid, phosphite and the like. In the process (1), the titanium catalyst is deactivated by contact with water, for example, at least 1% by weight of water is added to a polyester polyol and heated to 70 to 150 ℃, preferably to 90 to 130 ℃, for about 1 to 3 hours. The deactivation of the titanium catalyst under heating may be carried out at atmospheric pressure or under reduced pressure. After the deactivation treatment, the pressure in the system can be reduced, whereby water added to the system can be smoothly removed from the polyester polyol.
The polyether polyol (A-2) used in the present invention can be prepared by ring-opening polymerization of a cyclic ether in the presence of a diol and, if necessary, a small amount of a trifunctional or higher-functional polyfunctional alcohol component. The amounts of the diol and trifunctional or higher-functional polyfunctional alcohol components used in the ring-opening polymerization of the cyclic ether must be controlled so that the average number f of hydroxyl functional groups in the polyol composition (A) containing a predetermined amount of the polyether polyol (A-2) is within the prescribed range of 2.006 to 2.100 and the number average molecular weight of the polyether polyol (A-2) is within the prescribed range of 500 to 2500.
Examples of the polyether polyol (A-2) used in the present invention are polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polymethyltetramethylene glycol and the like. One or a mixture of two or more of these may be used in the present invention. Examples of trifunctional or higher-functional polyfunctional alcohol components which may be optionally used in the preparation of the polyether polyols are glycerol, trimethylolpropane, trimethylolbutane, trimethylolpentane, hexanetriol, pentaerythritol, diglycerol and the like. One or more of these alcohols may be used alone or in combination.
The polyol composition (A) used in the present invention may contain any other polyol as necessary in addition to the polyester polyol (A-1) and the polyether polyol (A-2). These polyols include, for example, polycarbonate polyols, polyester polycarbonate polyols, and the like. It is desirable that the polyol be present in the polyol composition (A) in an amount of up to 20 mole percent, the percentages being based on moles of all polyols making up the composition (A).
The organic diisocyanate (B) used in the preparation of the thermoplastic polyurethane of the present invention is not specifically defined, but may be any organic diisocyanate commonly used in the preparation of ordinary thermoplastic polyurethanes. Examples thereof are aromatic diisocyanates such as 4, 4 ' -diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, naphthalene-1, 5-diisocyanate, 3 ' -dichloro-4, 4 ' -diphenylmethane diisocyanate and the like; aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, and the like. One or more of these organic diisocyanates may be used alone or in combination. Among them, 4' -diphenylmethane diisocyanate is preferable. If desired, a small amount of a trifunctional or higher-functional polyfunctional polyisocyanate compound such as triphenylmethane triisocyanate or the like may also be added to the diisocyanate (B).
The chain extender (C) used in the preparation of the thermoplastic polyurethane of the present invention is not specifically defined, but may be any chain extender commonly used in the preparation of ordinary thermoplastic polyurethanes. Preferred are low-molecular compounds having at least two active hydrogen atoms in the molecule capable of reacting with isocyanate groups and a molecular weight of at most 300. Examples of the low molecular compound are diols such as ethylene glycol, propylene glycol, 1, 4-butanediol, 1, 6-hexanediol, 1, 4-bis (. beta. -hydroxyethoxy) benzene, 1, 4-cyclohexanedimethanol, bis (. beta. -hydroxyethyl) terephthalate, xylene alcohol and the like; diamines such as hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine and its derivatives, phenylenediamine, tolylenediamine, xylylenediamine, adipimide (adipimic acid dihydrazide), isophthaloyl dihydrazide, and the like; aminoalcohols, such as ethanolamine, propanolamine, and the like. One or more of these chain extenders may be used alone or in combination. Among them, preferred is an aliphatic alcohol having 2 to 10 carbon atoms, and more preferred is 1, 4-butanediol, because it can further improve the heat resistance and hot water resistance of the thermoplastic polyurethane and the thermoplastic elastic fiber obtained therefrom.
The process for the preparation of the thermoplastic polyurethanes of the invention is not specified explicitly. The thermoplastic polyurethane of the present invention is prepared from the polyester polyol (A-1), the polyether polyol (A-2), the organic diisocyanate (B), the chain extender (C) and other components as described above as necessary, wherein any well-known method can be applied. For example, there may be used a prepolymer method, a one-shot method, and other methods based on well-known urethane formation process methods, including melt polymerization, solution polymerization, and the like. Particularly preferred is melt polymerization, which results in thermoplastic polyurethanes in the substantial absence of solvent, and which is simple and efficient. Continuous melt polymerization using a multi-screw extruder is more preferable because of its high productivity. The urethanization reaction for preparing the thermoplastic polyurethanes of the present invention may be carried out in the presence of a tin urethanizing catalyst. It is desirable to conduct the urethanization reaction at a tin urethanization catalyst content of 0.5 to 10ppm based on the total weight of raw materials used in terms of tin atoms, because a thermoplastic polyurethane having a high molecular weight can be prepared. When the high molecular thermoplastic polyurethane is made into thermoplastic elastic fiber, the spinnability and the winding performance of the fiber are good, and the adhesion between the fibers in spinning and winding is reduced. In addition, such high molecular thermoplastic polyurethane can be made into polyurethane elastic fiber having excellent mechanical properties including heat resistance and the like. Examples of the tin urethane catalyst include dibutyltin diacetate and dibutyltin dilaurate. Dibutyl tin bis (ethoxybutyl-3-mercaptopropionate), and the like.
During or after the polymerization for preparing the thermoplastic polyurethane of the present invention, various additives commonly used in the production of ordinary thermoplastic polyurethanes, such as heat stabilizers, antioxidants, ultraviolet absorbers, flame retardants, lubricants, colorants, hydrolysis inhibitors, nucleating agents, weather-resistant modifiers, antifungal agents, and the like, may be added thereto as needed.
The polyurethane elastic fiber of the present invention can be produced by melt-spinning the thermoplastic polyurethane of the present invention. For producing the polyurethane elastic fiber by melt spinning, for example, the following methods are available:
[i] a previous process for preparing thermoplastic polyurethanes by reacting:
[1] a polyol composition (A) consisting essentially of a polyester polyol (A-1) having a crystallization enthalpy of at most 70J/g and a number average molecular weight of 1000 to 5000 and a polyether polyol (A-2) having a number average molecular weight of 500 to 2500, wherein the average number f of hydroxyl functional groups can be represented by the following formula (I):
f ═ all hydroxyl groups in the polyol making up the polyol composition }/{ making up the polyol composition
The number of molecules of all polyols of the compound } (I), f is between 2.006 and 2.100,
[2] an organic diisocyanate (B), and
[3] a chain extender (C) in a proportion satisfying the following formula (II):
1.00. ltoreq. B/(a + C). ltoreq.1.10 (II) wherein a represents the number of moles of all the polyols constituting the polyol composition (A), B represents the number of moles of the organic diisocyanate (B), and C represents the number of moles of the chain extender (C), followed by melt-spinning the resulting thermoplastic polyurethane; and
[ II ] A process for producing a thermoplastic polyurethane by melt-polymerizing the above-mentioned polyol composition (A), organic diisocyanate (B) and chain extender (C) at a ratio satisfying the above-mentioned formula (II), and directly spinning the melt of the obtained thermoplastic polyurethane through a spinneret.
In view of the physical properties of the resulting fiber and the ease of melt spinning operations, the melt spinning temperature is preferably no more than 260 ℃, but more preferably between 220 and 250 ℃. To further improve its properties, the polyurethane elastic fiber is preferably heat-aged at 50 to 100 ℃ after melt-spinning. The kind and type of spinning equipment used in melt spinning are not specifically defined, and any conventional melt spinning equipment commonly used for producing polyurethane elastic fibers can be used herein.
The polymerization degree of the thermoplastic polyurethane constituting the polyurethane elastic fiber of the present invention is not specifically defined. However, in view of heat resistance and hot water resistance of the polyurethane elastic fiber, the polymerization degree is preferably such that the logarithmic viscosity at 30 ℃ of the polyurethane elastic fiber dissolved in N, N-dimethylformamide containing 1% by weight of N-butylamine at a concentration of 0.5 deciliter/g is at least 0.5 deciliter/g, particularly preferably at least 0.7 deciliter/g, and the upper limit of the logarithmic viscosity thereof is infinite.
In particular, it is particularly preferred to produce the polyurethane elastic fiber of the present invention from a thermoplastic polyurethane having a high polymerization degree so that the obtained fiber is completely insoluble or only partially soluble in N, N-dimethylformamide containing 1% by weight of N-butylamine, because the polyurethane elastic fiber obtained from such a thermoplastic polyurethane having a high polymerization degree has significantly more excellent heat resistance and hot water resistance.
The fineness of the single fibers of the polyurethane elastic fiber of the present invention is not specifically defined, and may be determined as appropriate depending on the use of the fiber. Generally, the fineness of the single fiber is preferably about 10 to 100 denier. The polyurethane elastic fiber of the present invention may be in the form of monofilament or multifilament. For the latter multifilament, the number of filaments and the total denier are not specifically defined but may be appropriately determined. The cross-sectional shape of the polyurethane elastic fiber of the present invention is not also specifically defined, but may be any of circular, square, hollow, triangular, oval, flat multi-lobal, V-shaped, T-shaped, aligned, and other modified cross-sectional shapes. In order to produce various products from the polyurethane elastic fiber of the present invention, the fiber may be used alone or in combination with any other fiber in any desired manner.
The application of the polyurethane elastic fiber of the present invention is not specifically defined, and the fiber can be used for various purposes. By virtue of its elastic properties, the fiber can be used in sporting goods such as swimsuits and swim pants, outerwear, cycling wear, tights, and the like; garments, such as lingerie, liner, undergarment, and the like; accessories such as pantyhose, socks, body-protecting fabrics, hats, gloves, etc.; medical articles such as bandages, vascular prostheses, and the like; there are also non-clothing items such as tennis racket strings, raw yarns for integral molding of automobile sheets, yarns for coating metal on manipulators, and the like. In conclusion, the polyurethane elastic fiber of the present invention is very useful for applications particularly in sporting goods and clothing, and can fully utilize excellent properties such as excellent heat resistance, hot water resistance, elongation, elastic recovery and uniformity.
The present invention is more specifically illustrated by the following examples, which, however, are not intended to limit the scope of the present invention. In the following examples and comparative examples, the number average molecular weight of polyol, the crystallization enthalpy (Δ H) of polyester polyol, the spinning stability in the production of polyurethane elastic fiber, and the logarithmic viscosity, heat resistance, hot water resistance and elastic recovery modulus of polyurethane elastic fiber were evaluated by measurement according to the methods described below. Number average molecular weight of polyol
The number average molecular weight of each polyol sample was calculated on the basis of its hydroxyl value measured in accordance with JIS K-1577. Crystallization enthalpy (Δ H) of polyester polyol
The crystallization enthalpy (. DELTA.H) of each sample of the polyester polyol was measured by a differential scanning calorimeter (Rigaku thermoanalysis station, model TAS10, manufactured by Rigaku Denki Co., Ltd.). The amount of sample used was about 10 mg. The heat of the sample was measured in a nitrogen atmosphere according to the procedure described below. The crystallization enthalpy (. DELTA.H) of the sample can be obtained from the peak area after the step 3. Procedure for measuring crystallization enthalpy of polyester polyol:
step 1: heating the sample from room temperature to 100 ℃ at a heating rate of 100 ℃/min,
and the hot sample was held for 3 minutes.
Step 2: then, the sample was cooled from 100 ℃ to
100 ℃ and the cooled sample was kept for 1 minute.
And 3, step 3: at a heating rate of 10 ℃/min, the sample is heated again from-100 ℃ to
Spinning stability in the manufacture of polyurethane elastic fibers at 100 ℃
Using a single-screw extruder, each polyurethane sample was continuously spun at a spinning temperature of 220 ℃ to 245 ℃ for one week in the same manner as in the following examples or comparative examples, and the increase in pressure in the spinneret assembly (sand net: No. 60 to No. 80) was measured by a pressure gauge. The stability in spinning of the samples was evaluated on the basis of the following criteria: evaluation criteria for spinning stability:
o: continuous spinning is possible with little increase in pressure in the spin pack
Filament (pressure build-up: at most 4 kg/cm)2)。
And (delta): continuous spinning (pressure) is difficult due to the increased pressure in the spinneret pack
Increasing: from more than 4 to less than 8 kg/cm2)。
X: since the pressure in the spinneret assembly is increased much, continuous spinning is impossible
Filament (pressure build-up: 8 kg/cm)2Or higher). Logarithmic viscosity of polyurethane elastic fiber
A polyurethane elastic fiber sample was dissolved in N, N-dimethylformamide containing 1% by weight of N-butylamine to give a concentration of 0.5 dl/g. The down-flow time of the resulting polyurethane solution was measured at 30 ℃ with an Ubbelohde viscometer, from which time the logarithmic viscosity of the sample could be calculated according to the following formula:
logarithmic viscosity ═ ln (t/t)0)]Where t is the down-flow time (seconds) of the polyurethane sample solution, t0The down-flow time of the solvent (seconds),and c is the concentration (g/dl) of the polyurethane sample solution. Heat resistance of polyurethane elastic fiber
While maintaining 200% stretch in the wood frame, the polyurethane elastic fiber sample was heated for 1 minute in a dry oven at 140 ℃. From the untreated raw sample, the retention strength of the hot sample at 300% elongation can be obtained according to the following formula, which indicates the heat resistance of the sample.
Retention strength (%) at 300% elongation (M/M)0) X 100 where M is the 300% modulus of the treated sample, M0Is the 300% modulus of the sample before treatment. Hot water resistance of polyurethane elastic fiber
The hot water resistance of the polyurethane elastic fiber was evaluated by the same method as that of the polyurethane elastic fiber, except that the sample was immersed in hot water at 100 ℃ in an autoclave for 30 minutes. The retention strength of the treated sample was obtained in the same manner as above, which indicates the hot water resistance of the sample. Elastic recovery of polyurethane elastic fiber
The polyurethane elastic fiber samples were held at room temperature for 2 minutes at 300% stretch. After the pulling force was removed, the sample was left as it was for 2 minutes. The degree of elastic recovery was calculated according to the following equation.
Degree of elastic recovery (%) {1- (L-L)0)/L0} × 100 where L is the length of the sample (in mm) after 2 minutes of removal by pulling force, L0The original unstretched length of the specimen (in mm) was obtained. Elongation of polyurethane elastic fiber
Elongation of the polyurethane elastic fiber was obtained according to JIS K7311. Uniformity of polyurethane elastic fiber
A sample having a length of 50 m was collected from the polyurethane elastic fiber obtained by melt spinning. A roughness measuring device (keisakoki uniformity tester, model KEP-80C, manufactured by keisakokyo corporation) was slid in the longitudinal direction of the sample to check unevenness, which could be checked if there was unevenness in the roughness of the sample. The uniformity of the samples was evaluated according to the following criteria. Evaluation criteria for the uniformity of the elastic polyurethane fiber:
o: the unevenness in fiber coarseness is at most 1%.
And (delta): the unevenness in fiber coarseness is more than 1% to less than 3%.
X: the unevenness in fiber thickness is 3% or more.
Abbreviations for the compounds used for preparing the resins in the following examples and comparative examples are as follows.
BD: 1, 4-butanediol
MPD: 3-methyl-1, 5-pentanediol
TMP: trimethylolpropane
AD: adipic acid
Sb: sebacic acid
MDI: 4, 4-diphenylmethane diisocyanate
PTMG: polytetramethylene glycol reference example 1
950 g of MPD, 117.4 g of TMP and 954 g of AD were charged into a reactor, and esterified therein at 200 ℃ under atmospheric pressure while removing the produced water from the vessel by distillation (to the outside of the reaction system). When the acid value of the reaction product was at most 30, 30 mg of a titanium catalyst, tetraisopropyl titanate, was added thereto to carry out polymerization, the pressure of the reaction system was reduced to 100 to 200 mmHg, and the reaction was continued. When the acid value of the reaction product was 1.0, the vacuum degree in the vessel was gradually increased by a vacuum pump, and the reaction was stopped. Then, the reaction system was cooled to 100 ℃, 3% by weight of water was added thereto, and heated for 2 hours with stirring, thereby deactivating the titanium catalyst. Then, water was removed from the vessel by distillation under the reduced pressure, and 10ppm of dibutyltin diacetate as a tin catalyst was added to carry out urethanization reaction. In this process, the titanium catalyst was deactivated, followed by addition of a tin catalyst to conduct urethanization, to obtain a polyester polyol A. The number average molecular weight of the polyester polyol, the average number of hydroxyl functional groups in the polyester polyol, and the crystallization enthalpy (. DELTA.H) of the polyester polyol are shown in Table 1 below. Reference examples 2 to 9
The same procedure as in reference example 1 was repeated except that the polyol component and the dicarboxylic acid component listed in table 1 below were used. Briefly, after the esterification reaction, the titanium catalyst for polymerization is deactivated and the tin catalyst for the urethanization reaction is added. Thus, various polyester polyols shown in Table 1 were obtained, and the number average molecular weight of the polyester polyol, the average number of hydroxyl functional groups in the polyester polyol, and the crystallization enthalpy (. DELTA.H) of the polyester polyol are shown in Table 1 below.
TABLE 1
Example 1
| Composition of polyester polyol | Number average molecular weight | Average number of hydroxyl functional groups | Crystallization enthalpy (Δ H) [ Joule/gram ]] | |||
| Polyol component (molar ratio) | Dicarboxylic acid component | |||||
| Reference example 1 | Polyester polyol A | MPD/TMP＝(40.9) | AD | 800 | 2.100 | Not detected |
| Reference example 2 | Polyester polyol B | MPD/TMP＝(96.1) | AD | 2000 | 2.100 | Not detected |
| Reference example 3 | Polyester polyol C | MPD/TMP＝(165.2) | AD | 3500 | 2.100 | Not detected |
| Reference example 4 | Polyester polyol D | MPD/TMP＝(280.3) | AD | 6000 | 2.100 | Not detected |
| Reference example 5 | Polyester polyol E | MPD(-) | AD | 2000 | 2.000 | Not detected |
| Reference example 6 | Polyester polyol F | MPD/TMP＝(48.8) | AD | 2000 | 2.200 | Not detected |
| Reference example 7 | Polyester polyol G | MPD/TMP＝(97.5) | Sb | 2500 | 2.100 | 35 |
| Reference example 8 | Polyester polyol H | BD(-) | AD | 2000 | 2.000 | 77 |
| Reference example 9 | Polyester polyols I | BD/TMP＝(81.0) | AD | 2000 | 2.100 | 90 |
(1) The polyester polyol obtained in reference example 2, polyether polyols PTMG and BD, all of which had been heated to 80 ℃ and MDI heated to 50 ℃, were continuously injected into a twin-screw extruder (30 mm diameter, length/diameter ratio L/D of 36) having two screws rotating in the same axial direction in the proportions shown in table 2 below, and the mixture was continuously melt-polymerized by a metering pump to obtain a thermoplastic polyurethane while the barrel temperature of the extruder was maintained at 260 ℃. Subsequently, the resulting polyurethane melt was continuously extruded through a die into water, and then pelletized to prepare thermoplastic polyurethane pellets. The resulting granules were dried under vacuum at 80 ℃ for 24 hours.
(2) The dried pellets prepared in (1) are then fed into a conventional spinning apparatus equipped with a single-screw extruder and melt-spun into monofilaments at a spinning temperature of 200 ℃ to 240 ℃ and a spinning speed of 500 m/min. The filaments were then wound onto bobbins by cooling at a dew point of 10 ℃ with cold air. Thus, polyurethane elastic fiber (monofilament) (40 denier) was produced. The spinning stability during the manufacturing process was checked as described above, and the results obtained are shown in table 2 below.
(3) Aging the polyurethane elastic fiber produced in (2) at room temperature and a relative humidity of 60% for 10 days.
(4) The logarithmic viscosity, heat resistance, hot water resistance, elastic recovery, elongation and uniformity of the polyurethane elastic fiber aged in (3) were measured and evaluated in the manner as described above. The results obtained are shown in table 2 below.
Examples 2 to 10
(1) Thermoplastic polyurethane pellets were prepared in the same manner as in example 1, except that the polyester polyol and polyether polyol in Table 2 were used, and the proportions of the polyester polyol, polyether polyol, chain extender and organic diisocyanate to be mixed were different in Table 2. The obtained granules were also dried under vacuum in the same manner as in example 1.
(2) The thermoplastic polyurethane particles prepared in (1) were melt-spun into polyurethane elastic fibers (monofilaments) in the same manner as in example 1. The spinning stability of the pellets is shown in table 2 below.
(3) The polyurethane elastic fiber produced in (2) was aged in the same manner as in example 1, and the logarithmic viscosity, heat resistance, hot water resistance, elastic recovery, elongation and uniformity of the thus aged polyurethane elastic fiber were measured and evaluated in the same manner as described above. The results obtained are shown in table 2 below.
TABLE 2
| Examples | Polyester polyol (molar number) | Polyether polyol (mole number) | Average number of hydroxyl functional groups | Organic diisocyanate (molar) | Chain extender (moles) | b/(a+c) |
| 1 | B (0.5) | X (0.5) | 2.05 | MDI 3.34 | BD 2.24 | 1.03 |
| 2 | C (0.5) | X (0.5) | 2.05 | MDI 4.86 | BD 3.72 | 1.03 |
| 3 | B (0.5) | X (0.5) | 2.05 | MDI 3.47 | BD 2.24 | 1.07 |
| 4 | G (0.5) | X (0.5) | 2.05 | MDI 3.34 | BD 2.24 | 1.03 |
| 5 | B (0.2) | X (0.8) | 2.02 | MDI 3.34 | BD 2.24 | 1.03 |
| 6 | B (0.8) | X (0.2) | 2.08 | MDI 3.34 | BD 2.24 | 1.03 |
| 7 | F (0.1) | X (0.9) | 2.02 | MDI 3.34 | BD 2.24 | 1.03 |
| 8 | B (0.5) | X (0.5) | 2.05 | MDI 3.27 | BD 2.24 | 1.01 |
| 9 | B (0.5) | Y (0.5) | 2.05 | MDI 3.84 | BD 2.73 | 1.03 |
| 10 | B (0.5) | W (0.5) | 2.05 | MDI 2.83 | BD 1.75 | 1.03 |
Table 2 (continuation watch)
| Examples | Stability of spinning | Logarithmic viscosity [ deciliter/gram] | Heat resistance (%) | Hot water resistance [% ]] | Degree of elastic recovery [% ]] | Elongation [% ]] | Uniformity of |
| 1 | ○ | Insoluble matter | 60 | 54 | 94 | 480 | ○ |
| 2 | ○ | Insoluble matter | 62 | 55 | 94 | 490 | ○ |
| 3 | ○ | Insoluble matter | 58 | 56 | 92 | 470 | ○ |
| 4 | ○ | Insoluble matter | 62 | 60 | 91 | 460 | ○ |
| 5 | ○ | Insoluble matter | 62 | 57 | 93 | 460 | ○ |
| 6 | ○ | Insoluble matter | 64 | 52 | 91 | 470 | ○ |
| 7 | ○ | Insoluble matter | 63 | 59 | 92 | 460 | ○ |
| 8 | ○ | Insoluble matter | 57 | 52 | 92 | 490 | ○ |
| 9 | ○ | Insoluble matter | 61 | 56 | 91 | 460 | ○ |
| 10 | ○ | Insoluble matter | 58 | 53 | 91 | 460 | ○ |
W: PTMG 1000 (number average molecular weight 1000) manufactured by Mitsubishi chemical corporation
X: PTMG 1500 (number average molecular weight 1500) manufactured by Mitsubishi chemical corporation
Y: PTMG 2000 (number average molecular weight 2000) comparative examples 1 to 9 of Mitsubishi chemical corporation
(1) Thermoplastic polyurethane pellets were prepared in the same manner as in example 1, except that the polyester polyol and polyether polyol in Table 3 were used, and the proportions of the polyester polyol, polyether polyol, chain extender and organic diisocyanate to be mixed were different in Table 3. The obtained granules were also dried under vacuum in the same manner as in example 1.
(2) The thermoplastic polyurethane particles prepared in (1) were melt-spun into polyurethane elastic fibers (monofilaments) in the same manner as in example 1. The spinning stability of the pellets is shown in table 3 below.
TABLE 3
| Comparative examples | Polyester polyol (molar number) | Polyether polyol (mole number) | Average number of hydroxyl functional groups | Organic diisocyanate (molar) | Chain extender (moles) | b/(a+c) |
| 1 | D (0.5) | X (0.5) | 2.05 | MDI 7.40 | BD 6.2 | 1.03 |
| 2 | B (0.5) | X (0.5) | 2.05 | MDI 3.21 | BD 2.2 | 0.99 |
| 3 | B (0.5) | X (0.5) | 2.05 | MDI 3.69 | BD 2.2 | 1.14 |
| 4 | H (0.5) | X (0.5) | 2.00 | MDI 3.34 | BD 2.2 | 1.03 |
| 5 | I (0.5) | X (0.5) | 2.05 | MDI 3.34 | BD 2.2 | 1.03 |
| 6 | F (0.8) | X (0.2) | 2.16 | MDI 3.34 | BD 2.2 | 1.03 |
| 7 | E (0.5) | X (0.5) | 2.00 | MDI 3.34 | BD 2.2 | 1.03 |
| 8 | B (0.5) | Z (0.5) | 2.05 | MDI 3.34 | BD 2.2 | 1.03 |
| 9 | B (1.0) | - (0.0) | 2.10 | MDI 2.12 | BD 1.1 | 1.03 |
Table 3 (continuation watch)
| Comparative examples | Stability of spinning | Logarithmic viscosity [ deciliter/gram] | Heat resistance (%) | Hot water resistance [% ]] | Degree of elastic recovery [% ]] | Elongation [% ]] | Uniformity of |
| 1 | △ | Insoluble matter | 61 | 55 | 95 | 500 | △ |
| 2 | ○ | 1.15 | 27 | 30 | 93 | 490 | ○ |
| 3 | × | Insoluble matter | 40 | 46 | 88 | 350 | × |
| 4 | ○ | 1.25 | 31 | 30 | 85 | 420 | ○ |
| 5 | ○ | Insoluble matter | 60 | 56 | 82 | 410 | ○ |
| 6 | × | Insoluble matter | 60 | 50 | 86 | 450 | × |
| 7 | ○ | 1.25 | 33 | 45 | 95 | 450 | ○ |
| 8 | × | Insoluble matter | 61 | 57 | 85 | 300 | × |
| 9 | ○ | Insoluble matter | 40 | 47 | 94 | 480 | ○ |
X: PTMG 1500 (number average molecular weight 1500) manufactured by Mitsubishi chemical corporation
Y: PTMG 2000 (number average molecular weight 2000) from Mitsubishi chemical corporation
Z: PTMG 3000 (number average molecular weight 3000) from Mitsubishi chemical corporation
(3) The polyurethane elastic fiber produced in (2) was also matured in the same manner as in example 1, and the logarithmic viscosity, heat resistance, hot water resistance, elastic recovery, elongation and uniformity of the thus aged elastic polyurethane fiber were measured and evaluated in the same manner as described above. The results obtained are shown in Table 3.
As shown in Table 2, the thermoplastic polyurethane and polyurethane elastic fiber satisfying the requirements of the present invention have excellent properties of spinning stability, heat resistance, hot water resistance, elastic recovery, elongation and uniformity.
In contrast to the polyurethane elastic fibers of examples 1 to 10, it is shown in Table 3 that the polyurethane elastic fiber of comparative example 1, in which the polyester polyol D used had a large number average molecular weight, was poor in spinning stability and uniformity; the polyurethane elastic fiber of comparative example 2 is poor in heat resistance and hot water resistance, in which the mole number b of the organic diisocyanate used is small; the elastic polyurethane fiber in comparative example 3 is poor in properties, and the number of moles b of the organic diisocyanate used therein is large. In addition, it is also shown in Table 3 that the polyurethane elastic fiber of comparative example 4 is poor in heat resistance, hot water resistance elastic recovery and elongation, wherein the polyether polyol H used has a high crystallization enthalpy (. DELTA.H), and wherein the average number of hydroxyl functional groups in the polyol composition used is small; the polyurethane elastic fiber of comparative example 5, in which polyester polyol I having a high Δ H was used, had poor elastic recovery and elongation; the polyurethane elastic fiber in comparative example 6 is poor in hot water resistance, elastic recovery and uniformity, in which the average number of hydroxyl functional groups in the polyol composition used is large. In addition, table 3 shows that the elastic polyurethane fiber in comparative example 7 is poor in heat resistance and hot water resistance, in which the average number of hydroxyl functional groups in the polyol composition used is small; the spinning stability and uniformity of the polyurethane elastic fiber in comparative example 8 were poor, wherein polyether polyol Z having a large number average molecular weight was used; the polyurethane elastic fiber in comparative example 9, in which the polyether polyol (A-2) was not used, was poor in heat resistance and hot water resistance.
It will be apparent to those skilled in the art from this detailed description that various changes and modifications can be made herein without departing from the spirit and scope of the invention.
Claims (7)
1. A thermoplastic polyurethane prepared by the reaction of:
[1] a polyol composition (A) consisting essentially of a polyester polyol (A-1) and a polyether polyol (A-2), the polyester polyol having a crystallization enthalpy of at most 70J/g, a number average molecular weight of 1000 to 5000, the polyether polyol having a number average molecular weight of 500 to 2500, the molar ratio of the polyester polyol to the polyether polyol being 5/95 to 95/5, the polyol composition having an average number f of hydroxyl functional groups which can be represented by the following formula (I):
f ═ all hydroxyl groups in the polyol making up the polyol composition }/{ making up the polyol composition
The number of molecules of all polyols of the compound } (I), f is between 2.006 and 2.100,
[2] an organic diisocyanate (B), and
[3] a chain extender (C) in a proportion satisfying the following formula (II):
1.00. ltoreq. B/(a + C). ltoreq.1.10 (II) wherein a represents the number of moles of all the polyols constituting the polyol composition (A), B represents the number of moles of the organic diisocyanate (B), C represents the number of moles of the chain extender (C),
the polyether polyol (A-2) is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polymethyltetramethylene glycol; and
the organic diisocyanate (B) is selected from the group consisting of 4, 4 '-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, naphthalene-1, 5-diisocyanate, 3' -dichloro-4, 4 '-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate.
2. The thermoplastic polyurethane of claim 1, wherein the polyester polyol (A-1) is prepared by the reaction of a linear dicarboxylic acid, a branched acyclic primary diol, and a trifunctional and higher functionality alcohol, wherein the linear dicarboxylic acid is selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, and dodecanedioic acid; the branched non-cyclic primary diol is selected from the group consisting of 2-methyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol, 2-methyl-1, 4-butanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol; and the trifunctional or higher-functional alcohol is selected from the group consisting of glycerol, trimethylolpropane, trimethylolbutane, trimethylolpentane, hexanetriol, pentaerythritol, diglycerol.
3. The thermoplastic polyurethane of claim 1 wherein the chain extender (c) is selected from the group consisting of ethylene glycol, propylene glycol, 1, 4-butanediol, 1, 6-hexanediol, 1, 4-bis (. beta. -hydroxyethoxy) benzene, 1, 4-cyclohexanedimethanol, bis (. beta. -hydroxyethyl) terephthalate, xylene alcohol, hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine, phenylenediamine, tolylenediamine, xylylenediamine, adipamide, isophthalohydrazide, ethanolamine, and propanolamine.
4. A polyurethane elastic fiber comprising the thermoplastic polyurethane of claim 1.
5. A method of making a polyurethane elastic fiber comprising melt spinning a thermoplastic polyurethane, the thermoplastic polyurethane being prepared by the reaction of:
[1] a polyol composition (A) consisting essentially of a polyester polyol (A-1) and a polyether polyol (A-2), the polyester polyol having a crystallization enthalpy of at most 70J/g, a number average molecular weight of 1000 to 5000, the polyether polyol having a number average molecular weight of 500 to 2500, the molar ratio of the polyester polyol to the polyether polyol being 5/95 to 95/5, the polyol composition having an average number f of hydroxyl functional groups which can be represented by the following formula (I):
f ═ all hydroxyl groups in the polyol making up the polyol composition }/{ making up the polyol composition
The number of molecules of all polyols of the compound } (I), f is between 2.006 and 2.100,
[2] an organic diisocyanate (B), and
[3] a chain extender (C) in a proportion satisfying the following formula (II):
1.00. ltoreq. B/(a + C). ltoreq.1.10 (II) wherein a represents the number of moles of all the polyols constituting the polyol composition (A), B represents the number of moles of the organic diisocyanate (B), and C represents the number of moles of the chain extender (C), or comprises melt-spinning a thermoplastic polyurethane while the thermoplastic polyurethane is prepared by reacting the polyol composition (A), the organic diisocyanate (B) and the chain extender (C) in a predetermined ratio satisfying the formula (II),
the polyether polyol (A-2) is selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and polymethyltetramethylene glycol; and
the organic diisocyanate (B) is selected from the group consisting of 4, 4 '-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate, xylylene diisocyanate, naphthalene-1, 5-diisocyanate, 3' -dichloro-4, 4 '-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, and hydrogenated xylylene diisocyanate.
6. The process of claim 5, wherein the polyester polyol (A-1) is prepared by the reaction of a linear dicarboxylic acid selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, and dodecanedioic acid, a branched acyclic primary diol, and a trifunctional and higher-functional alcohol; the branched non-cyclic primary diol is selected from the group consisting of 2-methyl-1, 3-propanediol, 2-diethyl-1, 3-propanediol, 2-methyl-1, 4-butanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 2-methyl-1, 8-octanediol, 2, 7-dimethyl-1, 8-octanediol; and the trifunctional or higher-functional alcohol is selected from the group consisting of glycerol, trimethylolpropane, trimethylolbutane, trimethylolpentane, hexanetriol, pentaerythritol, diglycerol.
7. The process of claim 5 wherein the chain extender (c) is selected from the group consisting of ethylene glycol, propylene glycol, 1, 4-butanediol, 1, 6-hexanediol, 1, 4-bis (. beta. -hydroxyethoxy) benzene, 1, 4-cyclohexanedimethanol, bis (. beta. -hydroxyethyl) terephthalate, xylene alcohol, hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine, phenylenediamine, toluenediamine, xylylenediamine, dihydrazide, isophthaloyl dihydrazide, ethanolamine, and propanolamine.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19022898A JP4132244B2 (en) | 1998-07-06 | 1998-07-06 | Polyurethane elastic fiber comprising thermoplastic polyurethane and method for producing the same |
| JP190228/98 | 1998-07-06 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| HK1024252A1 HK1024252A1 (en) | 2000-10-05 |
| HK1024252B true HK1024252B (en) | 2004-07-16 |
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