HK1198337B - Elastic fabric - Google Patents

Description

Elastic fabric

Technical Field

The present invention relates to an elastic fabric, and more particularly, to an elastic fabric using a strong polyurethane elastic yarn that can achieve comfortable fit even in a thin and light fabric, as compared to a conventional elastic fabric containing polyurethane elastic fibers.

Prior Art

Due to its excellent stretch and recovery properties, elastic fiber is widely used in stretchable garments such as leg cuffs, underwear, and sportswear, in sanitary products such as diapers and sanitary napkins, and in commercial materials.

Recently, since polyurethane elastic fiber has high tenacity, high elastic restoring force, excellent heat resistance and suitable heat-setting ability not only when combined with synthetic fibers such as nylon yarn and polyester yarn but also when combined with natural fibers such as cotton and wool and semi-synthetic fibers, its use has been widely developed from among other elastic fibers.

In recent years, consumers have come to demand thinner and lighter materials for clothing based on the need for soft textured clothing that does not impede movement while exercising and provides more comfortable fit, combined with the increased income of double-workers into homes, and the increasing need for post-wash quick-drying clothing (close). Ultra fine fibers have been developed for so-called hard yarns such as nylon and polyester and have appeared on the market. Meanwhile, the demand for thinner polyurethanes has grown more strongly in recent years under a wider range of use environments.

Meanwhile, since the same stretch and recovery properties that are conventionally useful are required so as not to lose fit even when the fabric is thinned, even if, for example, the fineness is cut in half, the same force and recovery force must be maintained. In other words, in the field of practical use, in the case of elongation of 100% to 200%, a so-called "strong yarn" is required in the polyurethane elastic fiber having high acting force and restoring force per unit fineness.

A multifilament elastic yarn has been proposed as a means of increasing the acting force and restoring force of elastic fibers (patent document 1), wherein the multifilament elastic yarn is produced by irreversibly elongating polyurethane after melt spinning at shore hardness of 80 to 95 ° and then cooling immediately after winding at a speed of not less than 600 m/min. However, with this technique, higher forces can be achieved, where the multifilament elastic yarn has a force of 0.23-1.46cN/dtex at 100% elongation compared to a conventional polyurethane elastic yarn of 100% modulus, which is about 0.05 cN/dtex. However, since this technique has a low elongation at break of 145-160%, it is difficult to withstand processing in forming an elastic fabric and the elasticity formed in the cloth is not sufficiently stretched, and instead a garment that is uncomfortable and poorly fitting is made.

A manufacturing method of a polyurethaneurea has been proposed as a method for obtaining a polyurethane elastic fiber having a high tensile strength (patent document 2) in which a prepolymer is prepared by reacting a molar excess of an organic diisocyanate compound with a polymer diol having hydroxyl groups at both ends, and then spinning the polymer solution at a temperature range of 90 ℃ to 130 ℃ using a polyurethaneurea polymer solution obtained by reacting a diamine with the prepolymer; and a method of adding a specific alkyl sulfate or sulfate compound having a hydrocarbon group of 6 to 20 carbons (patent document 3). However, this document only mentions the modulus of elasticity and the breaking strength at 300%, and there is no suggestion about increasing the force and the restoring force at the time of 100-200% tensile elongation when forming an actual elastic fabric.

Documents of the prior art

Patent document

Patent document 1: japanese examined patent application H6-86683

Patent document 2: japanese unexamined patent application publication H9-59821

Patent document 3: patent No. 2968049

Summary of The Invention

Problems to be solved by the invention

The object of the present invention is to provide an elastic fabric having comfortable wearability and fit even in a thin and light fabric by using a strong polyurethane elastic fiber having at least 1.5 times the acting force and restoring force per unit fineness at the time of elongation of 100-.

Means for solving the problems

The present invention solves the above problems using any of the methods presented hereinafter.

(1) An elastic fabric comprising polyurethane elastic fibers made of a polyol having a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600, an organic diisocyanate compound, and a diamine compound.

(2) The elastic fabric according to item (1), wherein the molecular weight ratio of the polyol is at least 2.0. The number average molecular weight is at least 1.8.

(3) The elastic fabric according to item (1) or item (2), wherein the low molecular weight polyol is blended with the high molecular weight polyol.

(4) The elastic fabric according to any one of item (1) to item (3), wherein the polyol is a polyether-based polyol.

(5) The elastic fabric according to any one of item (1) to item (4), wherein a reaction equivalent ratio (molar ratio) of the organic diisocyanate compound to the polyol is less than 2.

(6) The elastic fabric according to any one of items (1) to (5), wherein the polyurethane elastic fiber is spun from a solution-polymerized polyurethane polymer solution by a prepolymer method.

(7) The elastic fabric according to any one of item (1) to item (6), wherein the polyurethane polymer is chain-extended with a diamine compound and has an end group concentration of 5 to 50meq/kg of polymer solid.

(8) The elastic fabric according to any one of items (1) to (7), wherein the polyurethane urea polymer has a number average molecular weight of between 40000 and 150000.

(9) The elastic fabric according to any one of items (1) to (8), wherein the polyurethane elastic fiber is spun by dry spinning the polyurethaneurea polymer solution.

(10) The fabric according to claim 1, wherein said polyurethaneurea has a diisocyanate to polyol molar ratio (end-capping ratio) of 1.3 to 1.7 and a prepolymer% NCO range of 2.6 to 3.8.

In one embodiment of the invention, the fabric comprises spandex (spandex fiber) made from a segmented polyurethaneurea. The polyurethaneurea comprises:

(a) polyols having a number average molecular weight of 450-;

(b) diisocyanates such as methylene bis (phenyl isocyanate) (MDI);

(c) a diamine compound such as ethylenediamine, or a mixture thereof with at least one diamine selected from aliphatic diamines and alicyclic diamines each having 2 to 13 carbon atoms;

(d) at least one monoamine, primary amine or secondary amine selected from aliphatic and alicyclic amines each having 2 to 12 carbon atoms.

The polyurethaneurea can have a molar ratio of diisocyanate to polyol in the range of 1.2 to 1.8, including 1.3 to 1.7, and a prepolymer% NCO range of 2.6 to 3.8.

Polyols having two or more different repeating units may be used by blending or copolymerization, but from the viewpoint of strength and recoverability, it is preferable to use blending of these two types: PTMG and 3M-PTG. [ commercially available examples of suitable polyols include Terathane 1000 and Terathane 650 (Wichita, KS. INVISTA) ]. The other polyols may also be blended or copolymerized in any manner so long as the properties of the PTMG, 3M-PTMG or both types of polyols are not lost.

Examples of polyether polyols that may be used include those having two or more hydroxyl groups from the ring-opening polymerization and/or copolymerization of ethylene oxide, propylene oxide, oxetane, tetrahydrofuran and 3-methyltetrahydrofuran, or from the polycondensation of polyols having less than 12 carbon atoms in each molecule, such as diols or mixtures of diols, such as ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, 1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol, 3-methyl-1, 5-pentanediol, 1, 7-heptanediol, 1, 8-octanediol, 1, 9-nonanediol, 1, 10-decanediol and 1, 12-dodecanediol. Linear difunctional polyether polyols are preferred. The polyol should have a number average molecular weight of about 450-. More specifically, poly (tetramethylene ether) glycols having a number average molecular weight of from about 600 to about 1100 can be used. The desired number average molecular weight may be achieved with a blend or mixture of two or more glycols that may be outside the desired molecular weight range.

Next, aromatic, alicyclic and aliphatic diisocyanate compounds may be used as the diisocyanate used in the present invention. Examples of the aromatic diisocyanate compound include, for example, diphenylmethane diisocyanate (hereinafter abbreviated as MDI), toluene diisocyanate, 1, 4-diisocyanate benzene, xylylene diisocyanate, 2, 6-naphthalene diisocyanate and the like. Examples of the alicyclic and aliphatic diisocyanates include, for example, methylenebis (cyclohexyl isocyanate) (hereinafter abbreviated as H12MDI), isophorone diisocyanate, methylcyclohexane 2, 4-diisocyanate, methylcyclohexane 2, 6-diisocyanate, cyclohexane 1, 4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotoluene diisocyanate, octahydro 1, 5-naphthalene diisocyanate, and the like.

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

Among these diisocyanate compounds, aromatic diisocyanate compounds are preferably used, and MDI is more preferably used, because they impart excellent strength and heat resistance to the elastic fiber. One or more other types of aromatic diisocyanate compounds may be blended with the MDI and used. The MDI may be a blend of 2,4 '-MDI isomers with 4, 4' -MDI isomers. One suitable MDI composition contains at least 90% of the 4, 4' -MDI isomer, such as Isonate125MDR from Dow Chemical^TMDesmodur from Bayer^®44M and Lupranate from BASF^®M。

In the manufacture of polyurethaneureas for spandex, a diol (such as PTMEG) is first reacted with MDI, optionally in the presence of a catalyst, to form an NCO-terminated prepolymer or "capped diol". The reaction is typically carried out as a homogeneously blended mixture with the application of heat at a temperature of 60 ℃ to 95 ℃ for a period of 1 hour to 6 hours. Amount of each reaction component, weight of glycol (W)_{Dihydric alcohol}) And the weight of MDI (W)_mdi) Adjusted by the Capping Ratio (CR), defined as the molar ratio of MDI to glycol, as shown below:

CR = (W_mdi/MW_mdi)/(W_{dihydric alcohol}/MW_{Dihydric alcohol})

Wherein MW_mdiIs a molecular weight of MDI (250.26) andMW_{dihydric alcohol}Is the number average molecular weight of the diol.

The reaction equivalent ratio (molar ratio or capping ratio) of the diisocyanate compound to the polyol is preferably more than 1 but less than 2.

A capping ratio in the range of 1.2 to 1.8 is preferred, but a capping ratio of 1.4 or more, but less than 1.6 is more preferred. Another suitable range of the capping ratio is 1.3 to 1.7. Within this range, elastic fibers having excellent strength and recoverability as well as excellent processability can be obtained. However, when the end capping ratio is more than 2, spinning becomes problematic because gel is generated during polymerization. In addition, as the gel portion generates low strength yarn, unstable quality occurs. On the other hand, when the end-capping ratio is less than 1.2, the heat resistance is deteriorated and the tensile breaking strength is lowered, resulting in a problem of quality.

For the polyurethane elastic fiber of the present invention, the diamine compound is a chain extender. When a diamine compound is used, high recoverability can be achieved.

Examples of the diamine compound which is a low-molecular-weight diamine compound include ethylenediamine, 1, 2-propylenediamine, 1, 3-propylenediamine, 2-methyl-1, 5-pentylenediamine, 1, 2-butylenediamine, 1, 3-butylenediamine, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane, 2-dimethyl-1, 3-diaminopropane, 1, 3-diamino-2, 2-dimethylbutane, 2, 4-diamino-1-methylcyclohexane, 1, 3-pentylenediamine, 1, 3-cyclohexanediamine, bis (4-aminophenyl) phosphine oxide, hexamethylenediamine, 1, 3-cyclohexyldiamine, hexahydro-m-phenylenediamine, hexahydro-phenylenediamine, 2-methylpentanediamine, 1, 7-heptanediamine, 1, 8-octanediamine, 1, 9-nonanediamine, 1, 10-decanediamine, 1, 12-dodecanediamine, isophorone diamine, xylene diamine, bis (4-aminophenyl) phosphine oxide, and the like. One or more of these diamines may be mixed and used. To the extent that the properties are not impaired, low molecular weight diol compounds such as ethylene glycol may be used together.

As the diamine compound, a diamine compound having 2 to 5 carbons is preferable, and when considering an elastic yarn having excellent elongation and elastic recoverability and the like, it is particularly preferable to use ethylenediamine or a diamine mixture containing at least 70 mol% of ethylenediamine. In addition to these chain extenders, a ternary amine compound (such as diethylenetriamine or the like) may be used to form a branched structure to the extent that the effects of the present invention are not impaired.

In order to control the molecular weight of the resulting polyurethane polymer, it is preferred to use a chain terminator during the chain extension reaction. When considering stabilization of yarn properties after spinning, the molar ratio of the chain extender to the chain terminator is preferably from 10 to 20, and more preferably will be from 14 to 18.

Examples of the chain terminator that can be used include monohydric alcohol compounds such as n-butanol; and monoamine compounds such as dimethylamine, diethylamine, cyclohexylamine and n-hexylamine. Monoamine compounds are preferred, and diethylamine is more preferred. Chain terminators are generally used by blending with chain extenders.

The polymerization method described above for the polyurethane elastic fiber polymerized from the polyol, the organic diisocyanate compound and the diamine compound is not particularly limited, and a melt polymerization method or a solution polymerization method and others may be used, but a solution polymerization method is more preferred. The solution polymerization process is advantageous in that less foreign matter, such as gel, is generated within the polyurethane.

When the solution polymerization method is used, the polyurethaneurea solution can be obtained by polymerizing in an organic solvent such as DMAc, DMF, DMSO, NMP or a solution using these as main components using a polyol, an organic diisocyanate compound, a diamine compound, and the like as raw materials. The reaction method is also not particularly limited, and examples include a one-shot method in which each raw material is introduced into a solution and dissolved, followed by heating to a suitable temperature to cause a reaction; or a prepolymer method in which a prepolymer is formed by first reacting a polyol with an organic diisocyanate compound in a non-solvent system and then the prepolymer is dissolved in a solvent and reacted with a diamine compound so as to chain-extend to synthesize a polyurethaneurea. The prepolymer method is preferred.

Further, when the polyurethane is synthesized, it is preferable to mix one or two types of catalysts, such as an amine-series catalyst and an organometallic catalyst.

Examples of the amine catalyst include 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' -tetramethylhexamethylenediamine, bis-2-dimethylaminoethylether, 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, and triethanolamine.

Examples of organometallic catalysts include tin octoate, dibutyltin dilaurate, dibutyltin octoate, and the like.

The concentration of polyurethane in the resulting polyurethaneurea polymerization solution is not particularly limited, but the polymer solid content in the solution is preferably between 20% and 60% by weight when considering the stretch and recovery properties of the resulting elastic yarn, the molecular weight of the polyurethane, and the solution viscosity. More preferably between 30 and 50 wt% and even more preferably between 35 and 45 wt%.

The concentration of the terminal groups of the diamine compound derived from polyurethane in the resulting polyurethaneurea polymerization solution is preferably between 5meq/kg and 50meq/kg, and more preferably between 10meq/kg and 45 meq/kg. When the end group concentration becomes higher than 50meq/kg, the molecular weight of the polymer is reduced, which in turn reduces the force and recoverability. In addition, when the end group concentration is less than 10meq/kg, a part will be gelled with an increase in molecular weight, leading to inconsistency in quality because a region of low strength and low elasticity is generated, and this causes a problem such as a decrease in productivity due to difficulty encountered in raising the concentration in consideration of the viscosity of the solution.

In addition, the measurement of the terminal group concentration of the diamine compound derived from the polyurethane elastic yarn was performed as follows. DMAc was added to the polyurethane solution to give a solution with a polyurethane concentration of 1.77 wt.%. Next, using an automatic titrator GT-100 manufactured by Mitsubishi chemical, a potentiometric titration was performed with p-toluenesulfonic acid (0.01N) to obtain a total content (a) of primary and secondary amines. Next, salicylaldehyde (20% isopropanol solution) was added to the similarly adjusted polyurethane solution and reacted with a primary amine, and thereafter the secondary amine was subjected to potentiometric titration with p-toluenesulfonic acid (0.01N) to obtain a secondary amine content (B). The end group concentration derived from the amine compound is calculated according to the following equation.

In another embodiment, the polyurethaneureas useful in preparing spandex can be described in terms of the weight percent of NCO groups after the capping reaction is complete. After the end-capping reaction is completed, when all hydroxyl groups (-OH) of the diol molecules are consumed by isocyanate groups (-NCO) from MDI to form urethane bonds, the weight percent NCO of NCO groups remaining on the prepolymer can be determined. The experimentally determined% NCO should match the theoretically calculated% NCO result, which is determined by the Capping Ratio (CR) as follows:

in one embodiment of the invention, the prepolymer preferably has an% NCO range of 2.60 to 3.80.

From the viewpoint of obtaining a fiber having high recovery and strength, the number average molecular weight of the polyurethaneurea polymer used in the present invention is preferably in the range of 40000-150000 as to the number average molecular weight. In addition, the molecular weight was measured by GPC and calculated based on polystyrene standards.

Examples of ultraviolet absorbers, antioxidants, and GAs-resistant stabilizers (gasresisant stablizers) that may be included in the polyurethane elastic fiber include hindered phenol medical agents such as BHT and "Sumilizer" GA-80 from Sumitomo Chemical; various benzotriazole series of medical agents, such as "Tinuvin"; phosphorus-containing medical agents, such as "Sumilizer" P-16 by Sumitomo Chemical; various hindered amine medical agents, such as "Tinuvin"; inorganic pigments such as zinc oxide, titanium oxide or carbon black; metal soaps, such as magnesium stearate; and an antibacterial agent containing silver, zinc or a compound of silver and zinc; a deodorant; lubricants such as silicone oil or mineral oil; various antistatic agents such as barium sulfate, cerium oxide, betaine, and phosphate. To further increase the resistance, particularly to light and various nitrogen oxides, nitric oxide scavengers such as HN-150 manufactured by Japan Hydrazine, inc; thermo-oxidative stabilizers such as "Sumilizer" GA-80 from Sumitomo Chemical; light stabilizers such as "Sumilizer" 300 #622 from Sumitomo Chemical, and the like.

These agents may be added to the polyurethane solution until spinning, and the method of addition or blending thereof may be selected at will. As a representative method, blending by a static mixer after adding to the spinning solution, or a stirring method is preferably used. Here, the additive is preferably added to the solution. The use of a solution enables the additives to be added uniformly to the polyurethane solution.

The spinning method in forming the polyurethane elastic fiber by spinning the polyurethane obtained by the solution polymerization method is not particularly limited, and known methods such as dry spinning and wet spinning may be suitably used. However, dry spinning is preferable from the viewpoint of productivity from the viewpoint that stable spinning can be performed for all the fineness from spun yarn to roving.

The fineness of the polyurethane elastic yarn of the present invention is not limited by the cross-sectional shape or the like. For example, the cross-sectional shape of the yarn may be circular or it may be flat.

In addition, the dry spinning method is not particularly limited, and the spinning can be performed by appropriately selecting spinning conditions and the like that match spinning equipment and desired properties.

For example, since the residual strain and initial stress of the polyurethane elastic fiber are particularly sensitive to the speed ratio of the godet to the winder, the properties are preferably appropriately determined according to the intended use of the yarn, and generally the speed ratio of the godet to the winder is preferably in the range of 1.1 to 1.8 for winding. Further, when considering improvement of the strength of the resulting polyurethane elastic fiber, a spinning speed of at least 250m/min is preferable.

The fabric of the present invention is constructed by using the polyurethane elastic fiber as described above. The fabric may be constructed of only the polyurethane elastic fiber, but the effects of the present invention can be achieved even in a combined elastic fabric in which, for example, polyester yarn or nylon yarn, etc. are combined with the polyurethane elastic fiber.

In other words, a material made by combining the polyurethane elastic fiber with the polyester yarn or the nylon yarn will be able to achieve a press fit (compression fit) with the fineness of the polyurethane elastic fiber described in the present invention of 33dtex or 22dtex, thereby enabling a comfortable press fit and fit with a thinner and lighter material, which was previously impossible to achieve with the conventional polyurethane elastic fiber with the yarn fineness of 44dtex, because the fabric can be made thinner and lighter, so improving the fit of the garment.

In addition, the fabric can also be used for knitted fabrics and woven fabrics. It can be used for knitted fabrics with warp knitting, weft knitting or circular knitting, and it can be used in any weave structure such as plain weave, twill weave, etc.

Examples

The present invention will be described in detail using the following examples. However, the present invention is not limited by these embodiments.

Measurement of force and recovery force of polyurethane elastic fiber

The force and the restoring force of the polyurethane elastic fiber were measured by using an Instron 550 tensile strength tester to obtain the force and the restoring force of the polyurethane elastic fiber.

A5 cm length of the test material was stretched 200% at a tensile strength of 50cm/min and repeated 5 times. The first applied force and the fifth applied force and restoring force were measured.

Production and evaluation of elastic Fabric

44dtex polyurethane elastic fiber was elongated to three times its length and covered with polyamide processed yarn (trademark "Kupe", manufactured by Toray, Inc. 33dtex, 26 filaments) at a twist speed of 800T/m to produce a single covered wire (SCY) with S-twist and Z-twist.

In addition, S-twist SCY was fed into feed ports 1,3 of a Panst knitting machine (Lonat, 400 gauge) at a knitting tension of 1.0g, and Z-twist SCY was fed into feed ports 2,4 to knit the knitted fabric.

Next, a dyeing process of the knitted fabric was performed as follows to obtain a knitted tight.

(1) Presetting: vacuum drying at 90 ℃ for 10 minutes.

(2) Dyeing: 2.0owf% of "Lanaset" (registered trademark) Black B, which was manufactured by Chiba specialty Chemicals, Inc., and processed at 90 ℃ for 60 minutes to be colored Black, was used for dyeing. Acetic acid and ammonium sulfate were applied for pH adjustment at the time of dyeing.

(3) Finally, softening processing was performed until the setting processing was completed (a Panst setter, setting: 11 ℃ C.. times.10 seconds, drying: 120 ℃ C.. times.30 seconds).

The tensile capacity and support strength (support strength) of the resulting knitted fabric were subjected to the following sensory evaluations.

Tensile ability evaluation score: 3: excellent stretching ability

2: slight lack of stretching ability

1: lack of stretching ability

Evaluation score of support strength: 3: excellent support

2: slight lack of support

1: lack of support

Example 1

The prepolymer was obtained by reacting 390g of poly (tetramethylene ether glycol) (PTMEG) having a molecular weight of 1000 with 151.12g of 4, 4' -diphenylmethane diisocyanate (MDI) in a nitrogen atmosphere in the non-solvent state at 80 ℃ for 3 hours. The residual isocyanate group after the reaction was 3.33% by weight.

540g of the resulting prepolymer was dissolved in 1166g of DMAc and a chain extender solution in which 132.48g of a 10 wt% ethylenediamine/DMAc solution was blended with 9.76g of a 10 wt% diethylamine/DMAc solution was added while stirring vigorously at 40 ℃ to obtain a 30 wt% concentration viscosity-adjusted polymer solution. The concentration of the terminal group of the diamine compound derived from the polymer solution was 24 meq/kg.

A polyurethane solution produced by reacting t-butyldiethanolamine with methylenebis (4-cyclohexyl isocyanate) was blended with a polycondensate of p-methoxycresol and divinylbenzene in a weight ratio of 2:1 to prepare a 30 wt% additive solution, followed by addition of DMAc. 96 parts by weight of the polyurethane polymer solution was blended with 4 parts by weight of the additive solution to prepare a spinning dope solution. It was dry-spun at a speed of 650m/min with a godet to winder speed ratio of 1.25 to obtain 33DTEX 4 yarn.

The properties of the obtained yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the obtained knitted fabric are shown in table 2.

Example 2

Spinning was performed under the same conditions as example 1 except that PTMEG having a molecular weight of 650 was used, which was adjusted to 1000 by blending 35 parts by weight of PTMEG having a molecular weight of 650 with 65 parts by weight of PTMEG having a molecular weight of 1400, to prepare a spinning concentrate solution by adding the additive solution to the polymerized polyurethane polymer solution.

The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Example 3

The prepolymer was obtained by reacting 390g of PTMEG having a molecular weight of 650 with 210g of MDI in a nitrogen atmosphere in the non-solvent state at 80 ℃ for 3 hours. The residual isocyanate group after the reaction was 3.36% by weight.

600g of the resulting prepolymer was dissolved in 1294.78g of DMAc, and a chain extender solution in which 149.04g of a 10 wt% ethylenediamine/DMAc solution was blended with 8.78g of a 10 wt% diethylamine/DMAc solution was added while vigorously stirring at 40 ℃ to obtain a 30 wt% concentration viscosity-adjusted polymer solution. The concentration of the terminal group of the diamine compound derived from the polymer solution was 19.5 meq/kg.

The additive solution was blended into the polyurethane polymer solution in the same manner as in example 1 to prepare a spinning concentrate and spun. The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Example 4

The prepolymer was obtained by reacting 400g of PTMEG having a molecular weight of 1400 with 121.42g of MDI in a nitrogen atmosphere in the non-solvent state at 80 ℃ for 3 hours. The residual isocyanate group after the reaction was 3.22% by weight.

520g of the resulting prepolymer were dissolved in 1122.66g of DMAc, and a chain extender solution in which 123.86g of a 10 wt.% solution of ethylenediamine/DMAc and 12.16g of a 10 wt.% solution of diethylamine/DMAc were blended was added while stirring vigorously at 40 ℃ to obtain a 30 wt.% concentration of a viscosity-adjusted polymer solution. The concentration of the terminal group of the diamine compound derived from the polymer solution was 31 meq/kg.

The additive solution was blended into the polyurethane polymer solution in the same manner as in example 1 to prepare a spinning concentrate and spun. The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Example 5

Spinning was performed under the same conditions as example 4 except that PTMEG having a molecular weight of 1400 was used by blending 50 parts by weight of PTMEG having a molecular weight of 1000 with 50 parts by weight of PTMEG having a molecular weight of 1800 to prepare a spinning concentrate solution by adding the additive solution to the polymerized polyurethane polymer solution.

The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Example 6

The prepolymer was obtained by reacting 400g of PTMEG having a molecular weight adjusted to 1200 with 137.50g of MDI in a nitrogen atmosphere in a non-solvent state at 80 ℃ for 3 hours, the PTMEG having been adjusted to 1200 by blending 62.5 parts by weight of PTMEG having a molecular weight of 1000 with 37.5 parts by weight of PTMEG having a molecular weight of 1800. The residual isocyanate group after the reaction was 3.38% by weight.

535g of the resulting prepolymer was dissolved in 1152.04g of DMAc, and a chain extender solution in which 133.92g of a 10% by weight solution of ethylenediamine/DMAc and 10.52g of a 10% by weight solution of diethylamine/DMAc were blended was added while stirring vigorously at 40 ℃ to obtain a 30% by weight concentration solution of viscosity-adjusted polymer. The concentration of the terminal group of the diamine compound derived from the polymer solution was 26 meq/kg.

The additive solution was blended into the polyurethane polymer solution in the same manner as in example 1 to prepare a spinning concentrate and spun. The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Comparative example 1

The prepolymer was obtained by reacting 400g of PTMEG having a molecular weight of 1800 with 87.78g of MDI in a nitrogen atmosphere in the non-solvent state at 90 ℃ for 2 hours. The residual isocyanate group after the reaction was 2.22% by weight.

485g of the resulting prepolymer were dissolved in 1071.67g of DMAc, and a chain extender solution in which 79.58g of a 10 wt% solution of ethylenediamine/DMAc and 10.41g of a 10 wt% solution of diethylamine/DMAc were blended was added while stirring vigorously at 40 ℃ to obtain a 30 wt% concentration solution of viscosity-adjusted polymer. The concentration of the terminal group of the diamine compound derived from the polymer solution was 28 meq/kg.

The additive solution was blended into the polyurethane polymer solution in the same manner as in example 1 to prepare a spinning concentrate and spun. The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

Comparative example 2

The prepolymer was obtained by reacting 400g of PTMEG having a molecular weight of 1800 with 105.56g of MDI in a nitrogen atmosphere in the non-solvent state at 90 ℃ for 2 hours. The residual isocyanate group after the reaction was 3.32% by weight.

505g of the resulting prepolymer was dissolved in 1084.80g of DMAc, and a chain extender solution in which 124.06g of a 10 wt% ethylenediamine/DMAc solution was blended with 16.24g of a 10 wt% diethylamine/DMAc solution was added while vigorously stirring at 40 ℃ to obtain a 30 wt% concentration viscosity-adjusted polymer solution. The concentration of the terminal group of the diamine compound derived from the polymer solution was 40 meq/kg.

The additive solution was blended into the polyurethane polymer solution in the same manner as in example 1 to prepare a spinning concentrate and spun. The properties of the resulting yarn are shown in table 1, and the sensory evaluation results of the tensile ability and the support strength of the knitted fabric are shown in table 2.

For examples 7-19, the following test methods were used:

the NCO content of the capped glycols was determined according to S.SIGGIa, "Quantitative Organic Analysis via Functional Group", third edition, Wiley & Sons, New York, pp 559-561 (1963).

The strength and elasticity of spandex fibers are measured according to the general methods of ASTM D2731-72. Three yarns, 2-inch (5-cm) gauge length and 0-300% elongation cycle were used for each measurement. The sample was cycled five times at a constant elongation rate of 50 cm/min. The stress on spandex during initial elongation was measured at 200% elongation on the first cycle: load power (TP 2) and is recorded as grams per denier. Unload power (TM 2) is the stress at 200% elongation at the fifth unload cycle and is also reported as grams per denier. Elongation at break (ELO) and strength (TEN) were measured at the sixth elongation cycle. The set was also measured on samples that underwent five 0-300% elongation/relaxation cycles. The percentage set (% set) was then calculated:

% set = 100 (L)_f-L_o)/L_o，

Wherein L is_oAnd L_fThe length of the filament (yarn) when held straight without tension before and after the five elongation/relaxation cycles, respectively.

Additionally, instead of a 0-300% stretch cycle, a 140 denier spandex yarn is stretched and cycled at, for example, a 15 gram force set tension. Stress-strain properties including load power, unload power and% set were measured and recorded.

Alternatively, the tensile properties of spandex at the break point were measured in a first cycle using an Instron tensiometer (Instron tensilester) equipped with a Textechno nip. The load power at 200% extension (TT2), elongation at break (TEL) and strength at break (TTN) were recorded.

Example 7

To a 2000ml Pyrex equipped with an air pressure driven stirrer, heating mantle and thermocouple temperature measuring device^®250.0 g of Terathane is arranged in a glass reaction kettle^®1000 diols (available from Invista, s. a. l. of Wichita, KS and Wilmington, DE) and 93.88 grams of molten Isonate125MDR (available from Dow Company, Midland, Michigan). The reaction mixture was stirred and heated to 90 ℃ in a glove box with a nitrogen atmosphere and held at that temperature for 120 minutes with continued stirring to complete the reaction to form the prepolymer. The NCO content, i.e.% NCO, of the capped glycol prepolymer was determined to be 2.962. 628.91 g of N, N-dimethylacetamide (DMAc) were added to the viscous prepolymer with vigorous stirring. Once the prepolymer is completely dissolved in the solventA mixture of 123.35 grams of a chain extender solution (containing ethylenediamine and 2-methyl-1, 5-pentanediamine in a molar ratio of 90: 10) and 4.75 grams of a chain terminator solution (containing diethylamine), both at a concentration of 2.0 milliequivalents/gram of DMAc solution, was added to the diluted and dissolved prepolymer solution with stirring over 10 seconds. The resulting viscous polymer solution was mixed for a further 15 minutes by continued stirring and subsequently stored in Nalgene^®In plastic bottles for spinning into fibers.

Example 8

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of example 8, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 1000250.00 g

Isonate125MDR 100.12 g

Measured% NCO 3.505%

DMAc 622.13 g

Extender solution 148.32 g

Terminator solution 5.04 g

Example 9

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of example 9, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 1000250.00 g

Isonate125MDR 96.99 g

Measured% NCO 3.235%

DMAc 625.17 g

Extender solution 135.73 g

Terminator solution 5.35 g

Example 10

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of example 10, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 1000250.00 g

Isonate125MDR 90.73 g

Measured% NCO 2.665%

DMAc 632.51 g

Extender solution 110.82 g

Terminator solution 4.35 g

Example 11

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of example 11, except that Terathane was used^®650 diols (available from Invista, s. a. l. of Wichita, KS and Wilmington, DE) were substituted for Terathane^®1000. Thus, the amounts of ingredients and the measured% NCO of the prepolymer were also varied as follows:

terathane 650250.00 g

Isonate125MDR 130.22 g

Measured% NCO 2.818%

DMAc 697.78 g

Extender solution 133.78 g

Terminator solution 4.87 g

Example 12

The same procedure and ingredients as in example 11 were used to prepare a polymer solution of example 12, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 650250.00 g

Isonate125MDR 135.26 g

Measured% NCO 3.201%

DMAc 691.60 g

Extender solution 153.89 g

Terminator solution 5.93 g

Example 13

The same procedure and ingredients as in example 11 were used to prepare a polymer solution of example 13, except that the chain extender solution, still at a concentration of 2.0 meq/g, was made with a mixture of ethylenediamine and 2-methyl-1, 5-pentanediamine in a molar ratio of 80: 20. The amounts of ingredients and the measured% NCO of the prepolymer were also varied as follows:

terathane 650250.00 g

Isonate125MDR 135.26 g

Measured% NCO 3.316%

DMAc 700.15 g

Extender solution 133.78 g

Terminator solution 4.87 g

Example 14

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of example 8, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 650250.00 g

Isonate125MDR 140.44 g

Measured% NCO 3.585%

DMAc 688.33 g

Extender solution 174.53 g

Terminator solution 7.05 g

Example 15

The same procedure and ingredients as in example 11 were used to prepare a polymer solution of example 15, except that the chain extender solution, still at a concentration of 2.0 meq/g, was made with only ethylenediamine in DMAc. The amounts of ingredients and the measured% NCO of the prepolymer were also varied as follows:

terathane 650250.00 g

Isonate125MDR 125.33 g

Measured% NCO 2.603%

DMAc 669.81 g

Extender solution 114.20 g

Terminator solution 6.129 g

Example 16

The same procedure and ingredients as in example 15 were used to prepare a polymer solution of example 16, except that the amounts of ingredients and the measured% NCO of the prepolymer were varied as follows:

terathane 650250.00 g

Isonate125MDR 130.22 g

Measured% NCO 2.845%

DMAc 693.59 g

Extender solution 133.78 g

6.99 g of terminator solution

Comparative example 3

The same procedure and ingredients as in example 7 were used to prepare a polymer solution of comparative example 3, except that Terathane was used^®1800 diols (available from Invista, s. a. l. of Wichita, KS and Wilmington, DE) instead of teraathane^®1000. Thus, the amounts of ingredients and the measured% NCO of the prepolymer were also varied as follows:

terathane 1800250.00 g

Isonate125MDR 58.68 g

Measured% NCO 2.614%

DMAc 578.12 g

Extender solution 93.93 g

Terminator solution 3.94 g

Each of the above polymer solutions prepared in the laboratory was spun into 40-denier, 3-filament yarns by a dry spinning process. The DMAc solvent was removed by flushing it through a spinning cell with heated nitrogen at 400 deg.C at a rate of 15 lbs/hr. The chamber wall temperature was controlled between 290 ℃ and 210 ℃ in multiple heating zones. A lubricating finish was applied to the dried yarn and wound onto a tube at the bottom of the spinning chamber at a speed of 667 yards per minute (ypm). The tensile properties of the freshly spun yarn (as-spun yarn) after aging on a tube for 24 hours at room temperature were determined and are provided in table 3 below.

It can be seen that examples 7-16 of the present invention exhibit significantly higher modulus (load power TP2 and TT2) and higher recovery power (unload power TM2) than comparative example 3.

Example 17

A polymer solution was prepared in the same manner as in example 9 and spun into 140-denier, 10-filament yarn. The heated nitrogen delivered to the spinning chamber was at 400 ℃ and a flow rate of 20 lbs/hr. The chamber wall temperature was controlled between 290 ℃ and 210 ℃ in multiple heating zones. A lubricating finish was applied to the dried yarn and wound onto a tube at the bottom of the spinning chamber at a speed of 667 yards per minute (ypm).

Example 18

A polymer solution was prepared in the same manner as in example 11 and was spun into 140-denier, 10-filament yarn using the same spinning conditions as in example 17, except that the winding speed was 600 yards per minute (ypm).

Example 19

A polymer solution was prepared in the same manner as in example 12 and was spun into 140-denier, 10-filament yarn using the same spinning conditions as in example 18.

Comparative example 4

The polymer solution was commercially produced in making LYCRA T162C spandex fibers and spun into 140-denier, 10-filament yarn using the same spinning conditions as in example 17.

Comparative example 5

The polymer solution was commercially produced from LYCRA T127 spandex fiber and spun into 140-denier, 10-filament yarn using the same spinning conditions as in example 17.

Tensile properties of the as-spun 140-denier yarn after 24 hours of aging on a tube at room temperature were measured and are provided in table 4.

As can be seen from Table 4, examples 17-19 of the present invention have a significantly higher modulus (or load power TP2) and higher recovery power (or unload power TM2) than the existing commercial product (comparative examples 4 and 5).

Claims (12)

1. An elastic fabric comprising polyurethane elastic fibers made of a polyether-based polyol having a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600, an organic diisocyanate compound, and a diamine compound, wherein the reaction equivalent ratio of the organic diisocyanate compound to the polyol is in the range of 1.2 to 1.8.

2. The elastic fabric of claim 1, wherein the ratio of weight average molecular weight to number average molecular weight is at least 1.8.

3. The elastic fabric of claim 1 or 2, wherein the low molecular weight polyol is blended with the high molecular weight polyol.

4. The elastic fabric of claim 1 or 2, wherein the reaction equivalent ratio of the organic diisocyanate compound to the polyol is in the range of 1.4 to 1.6.

5. The elastic fabric of claim 1 or 2, wherein the reaction equivalent ratio of the organic diisocyanate compound to the polyol is in the range of 1.3 to 1.7.

6. The elastic fabric according to claim 1 or 2, wherein the polyurethane elastic fiber is spun from a solution polymerized polyurethane polymer solution by a prepolymer method.

7. The elastic fabric of claim 6, wherein said polyurethane polymer is derived from a diamine compound and has an end group concentration of 5 to 50 meq/kg.

8. The elastic fabric of claim 6, wherein said polyurethane polymer has a number average molecular weight between 40000 and 150000, calculated using polystyrene as a standard.

9. The elastic fabric of claim 6, wherein said polyurethane elastic fiber is spun by dry spinning said polyurethane polymer solution.

10. The elastic fabric of claim 6, wherein said polyurethane polymer has a diisocyanate to polyol mole ratio of 1.3 to 1.7 and a% NCO range of said prepolymer of 2.6 to 3.8.

11. The elastic fabric of any of claims 1,2 and 7-10, wherein the minimum number average molecular weight is 600.

12. The elastic fabric of claim 1 or 2, wherein the reactive equivalent ratio is a molar ratio or a terminating ratio.