HK1121203A - Spandex compositions for high speed spinning - Google Patents

Description

Spandex composition for high speed spinning

Background

Technical Field

The present invention relates to novel spandex (spandex) compositions comprising poly (tetramethylene-co (co) -ethyleneether) glycols containing constituent units produced by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent and wherein the spandex filaments are spun at high speeds typically greater than 750 meters per minute.

Description of the related Art

Homopolymers of poly (tetramethylene ether) glycols, also known as polytetrahydrofuran or tetrahydrofuran (THF, oxolane), are well known for their use in the soft segment of polyurethaneureas. The poly (tetramethylene ether) glycols impart excellent dynamic properties to the polyurethaneurea elastomers and fibers. They have a very low glass transition temperature, but have a crystalline melting temperature above room temperature. Thus, they are waxy solids at ambient temperature and need to be maintained at elevated temperatures to prevent freezing.

Copolymerization with cyclic ethers has been used to reduce the crystallinity of polytetramethylene ether chains. This lowers the polymer melting temperature of the copolyether glycol and at the same time improves certain dynamic properties of the polyurethaneurea containing this copolymer as soft segment. Comonomers used for this purpose include ethylene oxide, which can reduce the copolymer melting temperature below ambient temperature depending on the comonomer content. The use of poly (tetramethylene-co-ethyleneether) glycols can also improve certain dynamic properties of polyurethaneureas, such as elongation at break (el) and low temperature properties, which are desirable for certain end uses.

Poly (tetramethylene-co-ethyleneether) glycols are known in the art. Their preparation is described in U.S. Pat. Nos.4,139,567 and 4,153,786. Such copolymers may be prepared by any known cyclic ether polymerization method, such as those described in "Polytetrahydrofuran" by p.dreyfuss (Gordon & break, n.y.1982). Such polymerization processes include catalysis with strong protic or lewis acids, heteropolyacids and perfluorosulfonic acids or acidic resins. In some cases, it may be advantageous to use a polymerization promoter, such as a carboxylic acid anhydride, as described in U.S. Pat. No.4,163,115. In these cases, the main polymer product is a diester, which needs to be hydrolyzed in a subsequent step to obtain the desired polymeric diol.

Poly (tetramethylene-co-ethyleneether) glycols offer advantages over poly (tetramethylene ether) glycols in certain specific physical properties. At ethyleneether contents above 20 mole%, poly (tetramethylene-co-ethyleneether) glycols are moderately viscous liquids at room temperature and have a lower viscosity than poly (tetramethylene ether) glycols of the same molecular weight at temperatures above the melting point of poly (tetramethylene ether) glycols. Certain physical properties of polyurethanes or polyurethaneureas made from poly (tetramethylene-co-ethyleneether) glycols outperform those made from poly (tetramethylene ether) glycols.

Spandex based on poly (tetramethylene-co-ethyleneether) glycols is also known in the art. For example, U.S. patent No.4,224,432 to Pechhold et al discloses the use of poly (tetramethylene-co-ethyleneether) glycols having low cyclic ether content to make spandex and other polyurethaneureas. Pechhold indicates that an ethyleneether content of greater than 30% is preferred. Pechhold does not teach the use of auxiliary extenders (coextenders), although it discloses that mixtures of amines can be used.

U.S. Pat. No.4,658,065 to Aoshima et al discloses the preparation of several THF copolyethers via the reaction of THF and a polyol using a heteropolyacid catalyst. Aoshima also discloses that copolymerizable cyclic ethers, such as ethylene oxide, may be included with THF during the polymerization. Aoshima discloses examples of spandex that can be made using copolyether glycols, but without spandex made from poly (tetramethylene-co-ethyleneether) glycol.

U.S. patent No.3,425,999 to axelrod et al discloses the preparation of polyether polyurethaneureas from poly (tetramethylene-co-ethyleneether) glycols for oil resistance and good low temperature performance. The poly (tetramethylene-co-ethyleneether) glycols have an ethyleneether content of 20 to 60 weight percent (equivalent to 29 to 71 mole percent). Axelrod does not disclose the use of these polyurethaneureas in spandex. Axelrood discloses that "the chain extenders most useful in the present invention are diamines selected from primary and secondary diamines and mixtures thereof". Axelrod further discloses that "preferred diamines are hindered diamines such as dichlorobenzidine and methylenebis (2-chloroaniline). The use of ethylenediamine is not disclosed.

U.S. Pat. No.6,639,041 to Nishikawa et al discloses fibers having good elasticity at low temperatures comprising polyurethaneureas made from polyols comprising copolyethers of THF, ethylene oxide and/or propylene oxide, diisocyanates and diamines and polymers solvated in organic solvents. Nishikawa teaches that these compositions have improved low temperature properties over standard homopolymer spandex. Nishikawa also notes that "at ethyleneether contents above about 37 mole% in copolyether glycol, the unload force at low elongation is unacceptably low, the elongation at break is reduced, and the set is increased, albeit very slightly. The examples in "Nishikawa show that elongation at break increases when the mole percentage of ethylene ether moieties in the copolyether increases from 22 mole% to 31 to 37 mole%, but decreases again after increasing to 50 mole%. In contrast, the spandex of the present invention exhibits a tendency to increase elongation at break when the mole percentage of vinyl ether moieties in the copolyether increases from 27 mole% to 49 mole%. All samples in this patent were spun at a speed of 650 m/min or less.

It is clear to any fiber manufacturer that spinning spandex faster allows more fiber to be produced in a given time and thus reduces manufacturing costs, but spinning speed is limited by the negative impact on some fiber properties. It is well known to those skilled in the art that increasing the spinning speed of a spandex composition reduces its elongation and increases its load capacity compared to the same spandex spun at a lower speed. Thus, the faster the spandex fiber is spun, the more the elongation is reduced and the load force is increased, thereby reducing the drawability (draftability) of the fiber. The reduced drawability results in the need to use more spandex in the garment construction and thus increases the cost of garment manufacture. It is therefore common practice to slow the spinning speed to increase the elongation and reduce the load force of spandex, thereby increasing its drawability in circular knitting (circular knitting) and other spandex processing operations.

One method of increasing productivity based on spinning technology is disclosed in U.S. patent No.6,916,896 to Selling et al. Selling describes the use of a polyurethaneurea composition mixed with a diisocyanate to increase the solubility of the polymer solution so that higher solids polyurethaneurea solutions can be spun. Productivity as measured by the weight of spandex yarn produced in a given time is improved even without the use of higher spinning speeds. The diisocyanates into which the polyurethaneureas of the present invention are not incorporated also have high solution solubility and have much higher productivity than seldng.

Another method for improving productivity by optimizing Spinning conditions is disclosed in JP2002-155421A "Dry-Spinning Process". JP2002-155421A discloses a method for improving productivity in dry spinning polyurethane. The method is based on adjusting the spinning chamber conditions to avoid drying gas flowing upwards in the spinning chamber and to avoid filament (threadline) lateral instability. Both examples of JP2002-155421A use poly (tetramethylene ether) glycol based spandex. JP2002-155421A does not disclose spandex types suitable for the present invention. The process of the present invention exhibits no dependence on spinning chamber conditions beyond those necessary to produce a suitably dry fiber (e.g., 0 to 0.5% dimethylacetamide solvent remaining in the fiber). Furthermore, additives are not necessary.

Applicants have observed that spandex spun at high speeds as well, i.e., in excess of 750 meters per minute, with poly (tetramethylene-co-ethyleneether) glycol having from about 16 to about 70 mole percent, e.g., in excess of about 37 to about 70 mole percent, of constituent units derived from ethylene oxide, as the soft segment base material, provides improved physical properties over other spandex spun at similar high speeds. Spandex based on other copolyether glycols, such as poly (tetramethylene-co-2-methyltetramethylene ether) or polyester glycols, such as copolyesters of ethylene glycol, 1, 4-butanediol and adipic acid, also has low loading forces. However, these spandex fibers also typically have low tenacity and/or low elongation, which limits their ability to be spun at speeds in excess of 1000 meters per minute.

The poly (tetramethylene-co-ethyleneether) glycol based spandex of the present invention has a combination of low load force, high elongation and sufficient tenacity that it can be spun at speeds in excess of 1300 meters/minute to produce fibers with excellent drawability in a circular knitting operation. In addition, the spandex of the present invention exhibits desirable shrinkage reduction in hot wet processing when spun at winding speeds in excess of 1000 meters/minute.

Summary of The Invention

The present invention relates to a spandex comprising a polyurethane or polyurethaneurea reaction product of: (a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent, such as from greater than about 37 to about 70 mole percent, (b) at least one diisocyanate, (c) at least one chain extender selected from the group consisting of diamines and diols, wherein the spandex is spun at a speed in excess of about 750 meters per minute. In one aspect of the invention, the polyurethane or polyurethaneurea reaction product of the spandex described above additionally comprises one or more polymeric diols.

The present invention also relates to a process for preparing the above spandex comprising: (a) contacting a poly (tetramethylene-co-ethyleneether) glycol with at least one diisocyanate to form a capped glycol in which a portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol at about 16 to about 70 mole percent, such as greater than about 37 to about 70 mole percent, (b) dissolving the capped glycol in a solvent, (c) contacting the solution of the capped glycol of (b) with at least one diamine or glycol chain extender, and (d) spinning the solution of (c) to spin at a speed in excess of about 750 meters per minute to form spandex.

Detailed Description

The present invention relates to novel spandex compositions made at high spinning speeds that improve some of the desirable properties of spandex fibers while minimizing the negative impact of high speed spinning on other properties. Given that all other factors remain unchanged, the manufacturing costs of these fibers are reduced in proportion to the increase in spinning speed due to increased spinning productivity and reduced capital costs. The improved properties are retractive force (i.e., higher unload force), toughness, and hot wet creep (i.e., reduced shrinkage when treated with hot water). The spandex composition of the invention comprises a polyurethane based on poly (tetramethylene-co-ethyleneether) glycol and a polyurethaneurea. Poly (tetramethylene-co-ethyleneether) glycols are valuable "soft segments" in polyurethane and polyurethaneurea polymers.

The segmented polyurethanes or polyurethaneureas of the present invention are made from a poly (tetramethylene-co-ethyleneether) glycol and optionally a polymeric glycol, at least one diisocyanate, and a difunctional chain extender. The poly (tetramethylene-co-ethyleneether) glycol or glycol mixture is first reacted with at least one diisocyanate to form an NCO-terminated prepolymer ("capped glycol"), which is then dissolved in a suitable solvent, such as dimethylacetamide, dimethylformamide, or N-methylpyrrolidone, and then reacted with a difunctional chain extender. Polyurethanes are formed when the chain extender is a diol. Polyurethaneureas (a subset of polyurethanes) are formed when the chain extender is a diamine. In the preparation of polyurethaneurea polymers that can be spun into spandex, the diol is extended by the sequential reaction of the hydroxyl end groups with a diisocyanate and one or more diamines. In each case, the diol must be chain extended to provide a polymer with the necessary properties, including tack. If desired, dibutyl tin dilaurate, stannous octoate, mineral acids, tertiary amines (e.g., triethylamine), N' -dimethylpiperazine, and the like, and other known catalysts can be used to assist in the capping step.

The poly (tetramethylene-co-ethyleneether) glycols used to make the polyurethanes and polyurethaneureas of the present invention can be made by the method disclosed in U.S. Pat. No.4,139,567 to Prukmayr using a solid perfluorosulfonic acid resin catalyst. Alternatively, any other acidic cyclic ether polymerization catalyst may be used to make these poly (tetramethylene-co-ethyleneether) glycols, such as heteropolyacids. Heteropolyacids and salts thereof useful in the practice of the present invention may be, for example, those catalysts used in the polymerization and copolymerization of cyclic ethers as described in U.S. Pat. No.4,658,065 to Aoshima et al. These polymerization methods may include the use of additional promoters (e.g., acetic anhydride), or may include the use of chain terminator molecules to adjust molecular weight.

The poly (tetramethylene-co-ethyleneether) glycols used to make the polyurethanes and polyurethaneureas of the present invention can comprise constituent units formed by copolymerizing tetrahydrofuran and ethylene oxide, wherein the portion of units derived from ethylene oxide (ethyleneether portion) is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent, for example, from greater than about 37 to about 70 mole percent, or from greater than about 37 to about 55 mole percent, or from greater than about 37 to about 50 mole percent. Optionally, the poly (tetramethylene-co-ethyleneether) glycol used to make the polyurethane or polyurethaneurea of the present invention can comprise constituent units formed by copolymerizing tetrahydrofuran and ethylene oxide, wherein the ethylene oxide-derived portion of the units (ethyleneether portion) is present in the poly (tetramethylene-co-ethyleneether) glycol from about 40 to about 70 mole percent, or from about 40 to 55 mole percent, or from about 40 to 50 mole percent. The percentage of units derived from ethylene oxide present in the glycol corresponds to the percentage of ethylene ether moieties present in the glycol.

The poly (tetramethylene-co-ethyleneether) glycols used to make the polyurethanes and polyurethaneureas of the present invention can have an average molecular weight of about 650 daltons to about 4000 daltons. Higher poly (tetramethylene-co-ethyleneether) glycol molecular weights can be advantageous for selected physical properties, such as elongation.

The poly (tetramethylene-co-ethyleneether) glycols used to make the polyurethanes and polyurethaneureas of the present invention can include small amounts of units derived from chain terminator glycol molecules, particularly non-cyclizing glycols. Non-cyclizing diols refer to diols that do not readily cyclize under the reaction conditions to form cyclic ethers. These non-cyclizing diols may include ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, 1, 4-butynediol, 2-dimethyl-1, 3-propanediol, and water.

Poly (tetramethylene-co-ethyleneether) glycols, optionally comprising at least one additional component, such as 3-methyltetrahydrofuran, ethers derived from 1, 3-propanediol, or other glycols incorporated in small amounts as molecular weight control agents, are also useful in making the polyurethanes and polyurethaneureas of the present invention and may be encompassed by the term "poly (tetramethylene-co-ethyleneether) or poly (tetramethylene-co-ethyleneether) glycol". The at least one additional component may be a comonomer of the polymeric glycol, or it may be another material mixed with the poly (tetramethylene-co-ethyleneether) glycol. The at least one additional component may be present to the extent that it does not detract from the beneficial aspects of the invention.

The polymeric glycols useful in making the polyurethanes or polyurethaneureas of the present invention can have an average molecular weight of about 650 daltons to about 4000 daltons. Useful polymeric glycols include poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyltetramethylene ether) glycol, poly (ethylene ether) glycol, poly (propylene ether) glycol, polycarbonate glycol, and polyester glycol, or combinations of such glycols. The polymeric diol may optionally comprise at least one additional component, such as another comonomer of the polymeric diol, or it may be another material blended with the polymeric diol, and this choice is included within the meaning of the term "polymeric diol". The at least one additional component may be present as long as it does not detract from the beneficial aspects of the invention. When the polymeric glycol is a polyester glycol, the polyester glycol is selected from the reaction product of (i) ethylene glycol, propylene glycol, butylene glycol, 2-dimethyl-1, 3-propanediol, and mixtures thereof and (ii) terephthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid, and mixtures thereof.

When the poly (tetramethylene-co-ethyleneether) glycol is blended with a polymeric glycol that is not a poly (ethyleneether) glycol, the combined poly (tetramethylene-co-ethyleneether) glycol and polymeric glycol can have a total percentage of units derived from ethylene oxide that is less than or equal to, for example, about 40 mole percent, or about 35 mole percent, or about 30 mole percent. When the poly (tetramethylene-co-ethyleneether) glycol is blended with the poly (ethyleneether) glycol, the combined poly (tetramethylene-co-ethyleneether) glycol and poly (ethyleneether) glycol has a total percentage of units derived from ethylene oxide of about 35 to about 70 mole percent, such as about 37 to about 70 mole percent, or about 40 to about 65 mole percent. Whether the polymeric glycol is a poly (ethylene ether) glycol or another polymeric glycol, in the blend, the poly (tetramethylene-co-ethyleneether) glycol and the polymeric glycol are each present at least 10 mole percent of the sum of the moles of poly (tetramethylene-co-ethyleneether) glycol and the moles of polymeric glycol.

Diisocyanates that may be used include, but are not limited to, 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, 1-isocyanato-2- [ (4-cyanatophenyl) methyl ] benzene, bis (4-isocyanatocyclohexyl) methane, 5-isocyanato-1- (isocyanatomethyl) -1, 3, 3-trimethylcyclohexane, 1, 3-diisocyanato-4-methyl-benzene, 2 '-toluene diisocyanate, 2, 4' -toluene diisocyanate, and mixtures thereof. Particularly preferred diisocyanates are 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, 1-isocyanato-2- [ (4-cyanatophenyl) methyl ] benzene and mixtures thereof. The most preferred diisocyanate is 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene.

When a polyurethane is desired, the chain extender is a diol. Examples of such diols that may be used include, but are not limited to, ethylene glycol, 1, 3-propanediol, 1, 2-propanediol, 3-methyl-1, 5-pentanediol, 2-dimethyl-1, 3-propanediol, 2, 4-trimethyl-1, 5-pentanediol, 2-methyl-2-ethyl-1, 3-propanediol, 1, 4-bis (hydroxyethoxy) benzene, and 1, 4-butanediol, and mixtures thereof.

When a polyurethaneurea is desired, the chain extender is a diamine. Such diamines that may be used include, but are not limited to, hydrazine, ethylenediamine, 1, 2-propylenediamine, 1, 3-propylenediamine, 1, 2-butylenediamine (1, 2-diaminobutane), 1, 3-butylenediamine (1, 3-diaminobutane), 1, 4-butylenediamine (1, 4-diaminobutane), 1, 3-diamino-2, 2-dimethylbutane, 4' -methylene-bis-cyclohexylamine, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane, 1, 6-hexamethylenediamine, 2-dimethyl-1, 3-diaminopropane, 2, 4-diamino-1-methylcyclohexane, N-methylaminobis (3-propylamine), 2-methyl-1, 5-pentanediamine, 1, 5-diaminopentane, 1, 4-cyclohexanediamine, 1, 3-diamino-4-methylcyclohexane, 1, 3-cyclohexanediamine, 1-methylene-bis (4, 4' -diaminohexane), 3-aminomethyl-3, 5, 5-trimethylcyclohexane, 1, 3-pentanediamine (1, 3-diaminopentane), m-xylylenediamine, and mixtures thereof.

Optionally, a chain terminator such as diethylamine, cyclohexylamine, n-hexylamine, or a monofunctional alcohol chain terminator such as butanol may be used to control the molecular weight of the polymer. In addition, higher functional alcohol "chain branching agents," such as pentaerythritol, or trifunctional "chain branching agents," such as diethylenetriamine, may be used to control solution viscosity.

The polyurethanes and polyurethaneureas of the present invention can be used in any application where polyurethanes or polyurethaneureas of this general type are used, but are of particular benefit in the manufacture of articles requiring high elongation, low modulus or good low temperature properties for use. They are particularly useful in the manufacture of spandex, elastomers, flexible and rigid foams, coatings (both solvent-based and water-based), dispersions, films, adhesives, and shaped articles.

As used herein, unless otherwise indicated, the term "spandex" refers to a manufactured fiber in which the fiber-forming substance is a long-chain synthetic polymer composed of at least 85% by weight of segmented polyurethane or polyurethaneurea. Spandex is also known as elastane.

The spandex of the present invention can be used to make knitted and woven stretch fabrics, and garments or fabric articles comprising such fabrics. Examples of stretch fabrics include circular, plain and warp knit fabrics, and plain, twill and satin fabrics. The term "garment" as used herein refers to articles of clothing such as shirts, pants, skirts, jackets, coats, work shirts, work pants, uniforms, outerwear, sportswear, swimwear, corsets, socks, and undergarments, as well as accessories such as belts, gloves, mittens, hats, hosiery, or footwear. The term "textile" as used herein refers to articles comprising fabric, such as clothing, and further includes sheets, pillowcases, bedspreads, bed clothes, blankets, comforters, duvets, sleeping bags, shower curtains, drapes, fabrics, tablecloths, diapers, wipes, dish cloths, and upholstery or protective covers for furniture.

The spandex of the present invention can be used alone or in combination with various other fibers in textiles, weft (including plain and circular knit) knits, warp knits, and personal hygiene fabrics, such as diapers. Spandex can be bare, covered with or entangled with companion (companion) fibers such as nylon, polyester, acetate, cotton, and the like.

Fabrics comprising the spandex of the present invention may also comprise at least one fiber selected from protein, cellulose, and synthetic polymer fibers or a combination of such members. As used herein, "protein fiber" refers to fibers composed of protein, including such naturally occurring animal fibers as wool, silk, mohair, cashmere, alpaca, angora, vicuna, camel, and other fur fibers. As used herein, "cellulosic fiber" refers to fibers made from tree or plant materials, including, for example, cotton, rayon, acetate, lyocell, flax, ramie, and other plant fibers. As used herein, "synthetic polymer fiber" refers to a manufactured fiber made from a polymer composed of chemical components or compounds including, for example, polyesters, polyamides, acrylics, spandex, polyolefins, and aramids.

Effective amounts of various additives may also be used in the spandex of the invention so long as they do not detract from the beneficial aspects of the invention. Examples include matting agents (e.g. titanium dioxide), and stabilizers (e.g. hydrotalcite, a mixture of huntite and hydromagnesite, barium sulfate, hindered phenols and zinc oxide), dyes and dye enhancers, bactericides, antiblocking agents, silicone oils, hindered amine light stabilizers, uv screeners and the like.

The spandex of the invention or fabrics comprising it can be dyed and printed by conventional dyeing and printing procedures, for example by an exhaust (exhaust) process from an aqueous dye liquor at 20 ℃ to 130 ℃, by padding the material comprising the spandex with the dye liquor, or by spraying the material comprising the spandex with the dye liquor.

When an acid dye is used, a conventional method can be followed. For example, in an exhaust process, the fabric may be added to an aqueous dye bath having a pH of 3 to 9 and then heated from a steady state of about 20 ℃ to 40-130 ℃ over a period of about 10 to 80 minutes. The dye bath and fabric are then held at 40 to 130 ℃ for 10 to 60 minutes before cooling. The unfixed dye is then washed from the fabric. The stretch and recovery properties of spandex can be best maintained with as little exposure time as possible above 100 ℃. Conventional methods can also be followed when using disperse dyes.

The term "washfastness" as used herein refers to the resistance of dyed fabrics to fading during domestic or commercial laundering. The lack of wash fastness can cause fading, sometimes referred to as bleeding, of articles that are not wash fast. This can cause a color change in the article laundered with a non-launderable article. Customers often require fabrics and yarns to exhibit wash fastness. Wash fastness is related to fabric composition, fabric dyeing and finishing processes, and laundering conditions. Today's garments require spandex with improved wash durability.

Conventional auxiliary chemical additives may be used to assist and further enhance the wash durability of the spandex of the invention. Anionic syntans can be used to improve wash fastness properties and also act as a dye retarding agent and retarder when minimal separation of dye is required between spandex and companion (partner) yarns. Anionic sulfonated oils are auxiliary additives with greater affinity for anionic dyes used to block spandex or companion (partner) fibers from the dye when uniform dyeing levels are desired. Cationic fixing agents may be used alone or in combination with anionic fixing agents to help improve wash fastness.

Spandex fibers can be formed from the polyurethane or polyurethaneurea polymer solutions of the present invention by fiber spinning methods, such as dry spinning or melt spinning. When spandex is desired, the polyurethaneurea is typically dry spun or wet spun. In dry spinning, a polymer solution comprising a polymer and a solvent is metered through a spinneret orifice into a spinning chamber to form filaments. Typically, the polyurethaneurea polymer is dry spun into filaments from the same solvent used for the polymerization reaction. A gas is passed through the chamber to evaporate the solvent, thereby solidifying the filaments. The filaments were dry spun at a take-up speed of at least 550 m/min. The term "spinning speed" as used herein refers to the winding speed, which is determined by and is the same as the speed of the capstan roller. The good spinnability of spandex filaments is characterized by few filament breaks in the spinning chamber and in the winding. Spandex can be spun as a monofilament or can be consolidated into a multifilament yarn by conventional techniques. Each filament is 6 to 25dtex per filament in decitex (dtex) of the fabric.

It is well known to those skilled in the art that increasing the spinning speed of a spandex composition reduces its elongation and increases its load capacity compared to the same spandex spun at a lower speed. It is therefore common practice to slow the spinning speed to increase the elongation and reduce the load force of spandex, thereby increasing its drawability in circular knitting and other spandex processing operations. However, reducing spinning speed also reduces manufacturing productivity.

Some desirable physical properties improve when spun faster into spandex fibers, while other fiber properties decrease at the same time. Reduced these properties include reduced elongation, and increased force (load force or modulus) required to draw the fiber, which is generally proportional to the increase in spinning speed. Both of these properties reduce the value of spandex to customers in the textile mill. The reduced elongation and increased load force can reduce the drawability of the fibers and thereby increase the amount of spandex needed to make elastic garments. Increased load forces may also result in reduced user comfort due to increased tensile resistance. Therefore, a balance must be struck between increasing fiber spinning speed to reduce the manufacturer's manufacturing costs and improve some fiber properties and minimizing the loss of product value to the user caused by the reduction in other desired fiber properties.

The drawability of spandex yarns can be limited by a number of factors. Draft is limited by yarn elongation unless it is first limited by some other factor. One example of other factors is the load force (or modulus). For example, if the needles in a cylindrical knitting machine are limited in operation to only 5 grams of tension, spandex fiber draft is limited by the draft created by the 5 grams of tension. One advantageous aspect of the present invention is that the poly (tetramethylene-co-ethyleneether) glycol based spandex maintains very high drawability in cylinder knitting, which is higher than high quality poly (tetramethylene ether) glycol based spandex even when the spandex of the present invention is wound at 50% higher speed than the comparative spandex. This is shown in table 1 below.

Lower load forces are required in most spandex end uses not only because of their positive effect on increased drawability, but also because lower load forces in elastic garments generally translate into improved user comfort. Higher elongation is similarly desirable not only because of its positive effect on increased drawability, but also because higher elongation in elastic garments can translate into higher available stretch in certain garment configurations.

One advantageous aspect of the present invention is that spandex based on poly (tetramethylene-co-ethyleneether) glycol where the ethyleneether content is 16 to 70 mole percent has much higher elongation and lower loading force than poly (tetramethylene ether) glycol based spandex when spun at similar speeds and conditions. Poly (tetramethylene ether) glycol based spandex cannot currently be spun at speeds much greater than about 870 meters per minute (m/min) due to the limitations imposed by high modulus and reduced elongation. Further increases in spinning speed reduce drawability and therefore reduce customer ratings so much that it is of no practical value. However, when poly (tetramethylene-co-ethyleneether) glycol-based spandex is spun at speeds up to 1300 m/min or more, the load force is increased and the elongation is reduced, but their values are still better than poly (tetramethylene ether) glycol-based spandex spun at much lower speeds. This is shown in tables 2 and 3 below. For example, all spandex of the present invention has lower loading at 100%, 200%, and 300% even at much higher speeds than comparative poly (tetramethylene ether) glycol based spandex (which is spun at 844 meters per minute). In addition, the spandex of the present invention, even though spun at much higher speeds, has higher elongation than comparative poly (tetramethylene ether) glycol-based spandex spun at 844 meters/minute. Spandex of the present invention can be spun at speeds in excess of 750 meters per minute, or in excess of 1000 meters per minute, or in excess of 1100 meters per minute.

Another factor that limits the draft of spandex yarns is the tenacity of the yarn or the stress or fracture resistance at breaking elongation. Breaks in spandex during knitting limit productivity and increase garment manufacturing costs. Accordingly, spandex users place some emphasis on higher tenacity. However, if another factor is limited drawability, higher toughness beyond the minimum required to avoid work fracture is undesirable. The inventors have found that higher spinning speeds of the spandex of the invention desirably increase tenacity. This is also shown in table 3 below.

It is generally desirable to increase the retractive force (unload force) of spandex fibers, since it is this retractive force that pulls the fabric constructions together in the elastic garment and imparts their desired properties. Increasing the unload power of spandex can allow the fabric manufacturer to achieve the desired amount of compression in the fabric using less spandex, or can allow the spandex manufacturer to spin in finer denier spandex with the same retractive power as larger spandex filaments with lower load power. Finer denier enables it to be used in more end uses, especially those with fine denier hard yarns.

Spandex fibers are typically exposed to hot water during dyeing and finishing (finish) in garment manufacture, where they shrink to some extent. It is desirable to have a low degree of spandex fiber shrinkage in the garment as it is dyed and finished, so that the final fabric shape and size can be maintained as desired. This can be simulated in the laboratory by measuring "hot wet creep" (a test designed to simulate shrinkage of spandex yarn when dyed). As shown in table 4 below, the spandex of the present invention has reduced "hot wet creep" at increased spinning speeds.

The following examples demonstrate the invention and its applicability. The invention is capable of other and different embodiments and its several details are capable of modifications in various obvious respects, all without departing from the scope and spirit of the present invention. Accordingly, the embodiments are to be regarded as illustrative rather than restrictive.

As used herein, unless otherwise indicated, the term "DMAc" refers to dimethylacetamide solvent, the term "% NCO" refers to the weight percentage of isocyanate end groups in the capped glycol, the term "MPMD" refers to 2-methyl-1, 5-pentanediamine, the term "EDA" refers to 1, 2-ethylenediamine, and the term "PTMEG" refers to poly (tetramethylene ether) glycol.

The term "capping ratio" as used herein refers to the molar ratio of diisocyanate to diol, which is determined on the basis of 1.0 mole of diol. Thus, the capping ratio is typically expressed as a single number, moles of diisocyanate per mole of diol. For the polyurethaneureas of the present invention, the preferred molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 1.2 to about 2.3. For the polyurethanes of the present invention, the preferred molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 2.3 to about 17, preferably from about 2.9 to about 5.6.

Material

THF and PTMEG (TERATHANE ® 1800) are available from Invista s. a. r.l., Wilmington, Delaware, USA. NAFION ® perfluorosulfonic acid resin is available from e.i. dupont de Nemours and Company, Wilmington, Delaware, USA.

Analytical method

Tenacity is the breaking stress in the sixth stretch cycle, or in other words, the resistance to break of the fiber at ultimate elongation. The load force is the stress at a given elongation in the first tensile cycle, or in other words the resistance of the fiber to stretching to a higher elongation. The unload force is the stress at a specified elongation in the fifth recovery cycle, or in other words, the recovery force at a specified elongation after the fiber has been cycled to 300% elongation 5 times.

Percent isocyanate-percent isocyanate of the capped glycol blends (% NCO) was determined using potentiometric titration according to S.Siggia method "Quantitative Organic Analysis via functional group", 3 rd edition, Wiley & Sons, New York, p.559-561 (1963).

Ethylene ether content-the poly of the invention(tetramethylene-co-ethyleneether) glycol having an ethyleneether content of¹H NMR measurement. Dissolving a sample of poly (tetramethylene-co-ethyleneether) glycol or blend in a suitable NMR solvent, such as CDCl₃Is neutralized and obtained¹H NMR spectrum. combining-OCH at 3.7-3.2ppm₂Integration of peaks with-C-CH combined from 1.8-1.35ppm₂CH₂The integrals of the-C-peaks were compared. -OCH₂Peaks from ethylene oxide bonds (-O-CH)₂CH₂-O-) and from a THF linkage (-O-CH)₂CH₂CH₂CH₂-O-), and-C-CH₂CH₂the-C-bond is derived from THF only. To find the mole fraction of ethylene ether linkages in poly (tetramethylene-co-ethyleneether) glycols, the reaction was conducted from combined-OCH₂-C-CH subtraction from integration of-peaks₂CH₂Integration of the-C-peak, then dividing the result by-OCH₂-integration of peaks.

Number average molecular weight-the number average molecular weight of poly (tetramethylene-co-ethyleneether) glycol is determined by the hydroxyl number method.

Strength and elasticity-the strength and elasticity of spandex were measured according to the general method of ASTM D2731-72. Tensile properties were measured using an Instron tensile tester. For each measurement, three filaments were used "as is", i.e., after aging for 24 hours at about 70 ° f and 65% relative humidity (+/-2%) in a controlled environment, 2 inches (5 cm) gauge length and 0-300% elongation cycle, from a winder, i.e., without washing or other treatment. The samples were cycled 5 times at a constant elongation rate of 50 cm/min and then held at 300% elongation for 30 seconds after the fifth elongation.

The load force, the stress on the spandex during initial elongation, was measured at 100%, 200%, or 300% elongation in the first cycle and is expressed in the table as grams/denier and is labeled "LP 1", "LP 2", or "LP 3", respectively.

Unload force, the stress at 100% or 200% elongation in the fifth unload cycle, also expressed as grams/denier; labeled "UP 1" or "UP 2", respectively. Percent elongation at break ("Elo") and tenacity were measured in the sixth tensile cycle using a modified Instron clamp attached to a rubber band to reduce slippage.

Percent set-unless otherwise indicated, percent set is also measured on samples that have undergone 5 cycles of 0-300% elongation/relaxation. Percent set ("% set") was calculated as follows:

% set-100 (Lf-Lo)/Lo

Where Lo and Lf are the filament (yarn) lengths when held straight without tension before and after 5 elongation/relaxation cycles, respectively.

Cylinder Knitting (CK) draw-in knitting, spandex is drawn (drafted) while being transferred from a supply package to a carrier plate and then to a needle due to the difference between the needle usage rate and the feed rate from the spandex supply package. The ratio of hard yarn supply rate (meters per minute) to spandex supply rate is typically 2.5 to 4 times (2.5x to 4x) large and is referred to as machine draft ("MD"). This corresponds to a spandex elongation of 150% to 300% or more. The term "hard yarn" as used herein refers to a relatively inelastic yarn such as polyester, cotton, nylon, rayon, acetate, or wool.

The total draft of a spandex yarn is the product of the process draft (MD) and the Package Draft (PD), which is the amount of spandex yarn that has been drawn on the supply package. For a given denier (or dtex), the spandex content of the fabric is inversely proportional to the total draw; the higher the total draft, the lower the spandex content. PR is a measured property called "percent package relaxation" and refers to 100 × (yarn length on package-length of relaxed yarn)/(yarn length on package). For spandex used on a cylindrically woven, elastic, single knit fabric, PR typically measures from 5 to 15. Using the measured PR, the Package Draft (PD) is defined as 1/(1-PR/100). Therefore, the Total Draft (TD) can also be calculated as MD/(1-PR/100). The yarn with 4x process draft and 5% PR had a total draft of 4.21x, while the yarn with 4x process draft and 15% PR had a total draft of 4.71 x.

For economic reasons, circular knitting machines typically attempt to use a minimum spandex content consistent with adequate fabric performance and uniformity. As mentioned above, increasing spandex draft is one way to reduce content. The main factor limiting the draw down is the percent elongation at break, so yarns with high percent elongation at break are the most important factor. Other factors, such as breaking tenacity, friction, yarn tackiness, denier uniformity, and yarn defects, can reduce the drawdown that can be practically achieved. Knitting machines provide a safety margin (margin) for these limiting factors by reducing the draft from the final draft (percent elongation to break measured). They usually determine this "sustainable draft" by increasing the draft until the knitting breaks reach an unacceptable level, for example 5 breaks per 1000 revolutions of the knitting machine, and then backing off until acceptable performance is restored.

The tension in the needles is also a limiting factor for the draft. The feed tension in the spandex yarn is directly related to the total draft of the spandex yarn. It also varies with the inherent modulus (load) of the spandex yarn. In order to maintain an acceptably low tension in knitting at high draft, it is advantageous for spandex to have a low modulus (load force).

The yarn, which is ideal for high drawability, therefore has a high percent elongation at break, low modulus (load force), sufficiently high tenacity, low friction and tack, uniform denier, and low defect levels.

Because of its stress-strain properties, spandex yarns are more drafted (stretched) as the tension applied to the spandex increases; conversely, the more the spandex is drafted, the higher the tension in the yarn. A typical spandex yarn path in a circular knitting machine is as follows. The spandex yarn is metered from a supply package, passed over or through a break detector, over one or more direction-changing rollers, and then to a carrier plate, which guides the spandex to needles and into stitches. As the spandex yarn is drawn from the supply package and over each device or roll, a tension buildup develops in the spandex yarn due to the frictional forces generated by each device or roll in contact with the spandex. The total spandex draft at the stitch is thus related to the total amount of tension across the path of the spandex.

Residual DMAc in spandex-the percentage of DMAc remaining in a sample of spandex was determined using a Duratech DMAc analyzer. DMAc was extracted from a known weight of spandex using a known amount of tetrachloroethylene (perclene). The amount of DMAc in tetrachloroethylene (perclene) was then quantified by measuring the uv absorption of DMAc and comparing the value to a normalized curve.

Hot Wet creep-by measuring the initial length, L, of the yarn₀It was stretched to 1.5 times its original length (1.5L)₀) It is immersed in a water bath maintained at 97 to 100 ℃ for 30 minutes in a stretched state, taken out of the bath, released from tension and allowed to relax at room temperature for a minimum of 60 minutes, and then measured for a final length L_fThereby determining Hot Wet Creep (HWC). The percent hot wet creep is calculated by the following formula:

％HWC＝100×[(L_f-L₀)/L₀]

fibers with low% HWC provide excellent performance in heat and moisture finishing operations (e.g., dyeing).

Examples

Examples 1-31 (Spandex with ethylene ether)

Random poly (tetramethylene-co-ethyleneether) glycols having the mole percent ethyleneether units and number average molecular weight shown in tables 1, 2 and 4 were capped with 1-isocyanato-4- [ (4-isocyanato-phenyl) methyl ] benzene at 90 ℃ for 120 minutes using 100ppm mineral acid as catalyst to produce prepolymers having the diisocyanato/diol mole ratios (capping ratios) shown in the tables. This capped glycol was then diluted with DMAc solvent, chain extended with EDA, and chain capped with diethylamine to produce a spandex polymer solution. The amount of DMAc used is such that the final spinning solution has 36 to 38 weight percent polyurethaneurea based on total solution weight. The spinning solution was dry spun onto a column supplied with dry nitrogen, coagulated, passed over a godet roll and wound up at the speeds listed. The spin bin temperature and suction gas flow rate were adjusted to produce a residual solvent content of 0.1 to 0.7%. The filaments exhibit good spinnability. The fiber properties are listed in tables 1 to 4.

Comparative examples "1-5" (PTMEG Keystone spandex)

Poly (tetramethylene ether) glycol having an average molecular weight of 1800 daltons was capped with 1-isocyanato-4- [ (4-isocyanato-phenyl) methyl ] benzene at 90 ℃ for 90 minutes to produce a prepolymer having a diisocyanato/diol molar ratio of 1.69. This capped glycol was then diluted with DMAc solvent, chain extended with a mixture of EDA and MPMD at a ratio of 90/10, and chain capped with diethylamine to produce a spandex product similar in composition to high quality commercial spandex. The amount of DMAc used was such that the final spinning solution contained 35 wt.% polyurethaneurea based on the total solution weight. The spinning solution was dry spun onto a column supplied with dry nitrogen, coagulated, passed over a godet roll and wound up at the speeds listed. The filaments exhibit good spinnability. The fiber properties are listed in tables 1 to 4.

TABLE 1

Examples	％EO	End capping ratio	Chain extender	Diol MW	Number of filaments per filament	Winding speed (meter/minute)	PRM(％)	CK processing draft	Total draft
										12345678	2727272738383838	1.631.631.631.631.71.71.71.77	100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA	20102010201020102500250025002500	34444443	8448701100128087011001280844	14.719.219.520.419.521.018.714.0	4.14.13.83.64.34.13.74.1	4.805.084.724.525.345.194.554.77

9	49	1.64	100％EDA	2045	4	870	15.8	4.5	5.34
										Comparative example 1 comparative example 2	00	1.691.69	90/10DA/MPMD90/10DA/MPMD	18001800	34	8441100	11.616.8	3.83.4	4.304.09

Examination of the data in table 1 shows several different spandex fibers with different ethyleneether content, capping ratio, glycol molecular weight, number of filaments per filament, and winding (spinning) speed, with a total circular knit stretch that exceeds that of spandex based on poly (tetramethylene ether) glycol. Both examples 4 and 7 had a total draft exceeding that of the spandex of comparative example 1, even though they were wound at speeds over 50% higher.

TABLE 2

Examples	％EO	Diol MW	End capping ratio	Chain extender	Anti-chlorine additive%	Winding speed (meter/minute)	Number of filaments per filament	Residual solvent (%)
									101112131415161718192021	383838272727494937373737	250025002500201020102010204920491885188518851885	1.701.701.701.631.631.631.641.641.601.601.601.60	EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％	444444440000	8441100128087011001280870110084487011001280	344444443444	0.170.190.250.180.360.360.230.210.720.740.730.82
22	37	1885	1.72	90/10EDA/MPMD	0	844	3	0.79
									23	37	1885	1.72	90/10EDA/MPMD	0	1100	4	0.79
Comparative example 3	0	1800	1.69	90/10EDA/MPMD	0	870	4	0.42
									Comparative example 4	0	1800	1.69	90/10EDA/MPMD	0	1100	4	0.65
Comparative example 5	0	1800	1.69	90/10EDA/MPMD	0	1280	4	0.48

Table 2 shows the compositional details of several different spandex fibers differing in ethylene ether content, glycol molecular weight, end-capping ratio, chain extender type, additive amount, winding (spinning) speed, number of filaments per filament, and residual spin solvent. All of these were 44dtex spun fibers. The number of filaments affects the drying rate of the fiber; thus, the amount of residual solvent in the fiber after spinning is given. Drying the fiber to lower residual solvent levels also affects the resulting fiber properties. Generally, drying the fibers more increases the retractive or unload force. Thus, examples of a given composition with similar residual solvent were selected for comparison by winding speed.

TABLE 3

Examples	ELO(％)	SET(％)	TEN(g/den)	UP1(g/den)	UP2(g/den)	LP1(g/den)	LP2(g/den)	LP3(g/den)
									10	640	22.5	0.5384	0.0170	0.0314	0.0530	0.0848	0.1200
11	632	22.5	0.6721	0.0177	0.0336	0.0655	0.1068	0.1567
									121314151617181920212223 comparative example 3 comparative example 4 comparative example 5	630634587539630546622721611537584528443411397	22.026.525.924.226.623.331.533.332.529.930.532.227.425.223.9	0.75470.65570.70010.88680.54830.60970.49870.50000.54430.55850.55770.57550.89120.87011.0288	0.01820.01580.01720.01750.01690.01850.01560.01600.01620.01780.01620.01710.01700.01740.0183	0.03490.03130.03410.03570.03410.03770.03280.03380.03430.03740.03410.03650.02810.02890.0317	0.06980.07060.08460.07980.06530.06570.07620.09410.10100.10540.0813O.1082O.10810.11790.1134	0.11510.11490.13690.1431O.10280.11420.11340.13060.1445O.15960.12300.16960.21700.24290.2595	0.1705O.1639O.19830.22680.14260.17010.15210.16620.19090.22400.16020.24430.40490.29900.5548

Table 3 shows the physical properties of the example fibers from table 2. Examination of the data in table 3 shows that for each of the example and comparative example compositions, higher winding speeds increased the retractive force at 100% and 200% elongation in the fifth recovery cycle (UP1 and UP2) and the load force at 100%, 200% and 300% elongation in the first elongation cycle (except comparative example 4, which has a higher residual solvent content). Even though spun at a 1280 m/min wind-up speed, the inventive examples had much lower load force and higher elongation than the comparative example 3 spandex spun at 870 m/min. It can thus be seen that embodiments of the present invention, when spinning at all these winding speeds, even above 1000 meters/minute, can also be further drafted in a circular knitting operation before the tension or elongation in the needles limits the draft of the spandex.

TABLE 4

Examples	％EO	Diol MW	End capping ratio	Chain extender	Winding speed (meter/minute)	Hot wet creep
							2425262728293031 comparative example 1	37373749492727270	190019001900204920492045204520451800	1.601.601.601.641.641.631.631.631.69	100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA100％EDA90/10EDA/MPMD	87011001280870110087011001280844	16.515.113.216.513.213.212.911.715.6

Examination of the data in table 4 shows that increasing the winding speed of the examples of the invention reduces hot wet creep and can be used to reduce creep to a level lower than the comparative spandex.

Claims (20)

1. A spandex comprising a polyurethane reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent, preferably from greater than about 37 to about 55 mole percent;

(b) at least one diisocyanate;

(c) at least one chain extender selected from the group consisting of diamines and diols; and

wherein the spandex is spun at a speed in excess of about 750 meters per minute, preferably in excess of about 1000 meters per minute.

2. The spandex of claim 1 wherein the diisocyanate is selected from the group consisting of 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, 1-isocyanato-2- [ (4-isocyanatophenyl) methyl ] benzene and mixtures thereof.

3. The spandex of claim 1 wherein the chain extender is selected from the group consisting of hydrazine, ethylenediamine, 1, 2-propylenediamine, 1, 3-propylenediamine, 1, 2-diaminobutane, 1, 3-diaminobutane, 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-cyclohexanediamine, 2-methyl-1, 5-pentanediamine, 1, 3-pentanediamine, 4' -methylene-bis-cyclohexylamine, and mixtures thereof.

4. The spandex of claim 2 wherein the poly (tetramethylene-co-ethyleneether) glycol has a number average molecular weight of from about 650 daltons to about 4000 daltons and the molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 1.2 to about 2.3.

5. The spandex of claim 1 wherein the poly (tetramethylene-co-ethyleneether) glycol has a number average molecular weight of from about 650 daltons to about 4000 daltons, the portion of units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol at from greater than about 37 to about 50 mole percent, the molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 2.3 to about 17, and the chain extender is selected from the group consisting of ethylene glycol, 1, 3-propylene glycol, 1, 2-propylene glycol, 3-methyl-1, 5-pentanediol, 2-dimethyl-1, 3-propylene glycol, 2, 4-trimethyl-1, 5-pentanediol, 2-methyl-2-ethyl-1, 3-propanediol, 1, 4-bis (hydroxyethoxy) benzene, and 1, 4-butanediol.

6. The spandex of claim 3 wherein the diisocyanate is selected from the group consisting of 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, 1-isocyanato-2- [ (4-isocyanatophenyl) methyl ] benzene and mixtures thereof and the molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 1.2 to about 2.3.

7. The spandex of claim 3 wherein the diisocyanate is 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene and the ethylene oxide-derived moiety is present in the poly (tetramethylene-co-ethyleneether) glycol from greater than about 37 to about 50 mole percent

8. The spandex of claim 1 further comprising a polymeric glycol selected from the group consisting of poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyltetramethylene ether) glycol, poly (ethylene ether) glycol, poly (propylene ether) glycol, polycarbonate glycol, polyester glycol, and combinations thereof.

9. The spandex of claim 8 wherein the combined poly (tetramethylene-co-ethyleneether) glycol and polymeric glycol are each present at least 10 mole percent of the sum of the moles of poly (tetramethylene-co-ethyleneether) glycol and the moles of polymeric glycol.

10. The spandex of claim 8 wherein the polymeric glycol is a poly (ethylene ether) glycol and wherein the combined poly (tetramethylene-co-ethyleneether) glycol and poly (ethylene ether) glycol have a total percentage of units derived from ethylene oxide in the spandex of from about 35 to about 70 mole percent.

11. The spandex of claim 8 wherein the polymeric glycol is selected from poly (tetramethylene ether) glycol, poly (tetramethylene-co-2-methyltetramethylene ether) glycol, poly (propylene ether) glycol, polycarbonate glycol, polyester glycol, or combinations thereof, and wherein the combined poly (tetramethylene-co-ethyleneether) glycol and polymeric glycol have a total percentage of units derived from ethylene oxide of less than or equal to about 35 mole percent.

12. A process for making spandex comprising:

(a) contacting a poly (tetramethylene-co-ethyleneether) glycol with at least one diisocyanate to form a capped glycol in which a portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) dissolving the capped glycol in a solvent;

(c) contacting the solution of capped glycol of (b) with at least one diamine or glycol chain extender; and

(d) spinning the solution of (c) to a speed in excess of about 750 meters per minute to form spandex.

13. The process of claim 12 wherein the diisocyanate is 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, the molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 1.2 to about 2.3, and the chain extender is selected from the group consisting of hydrazine, ethylenediamine, 1, 2-propylenediamine, 1, 3-propylenediamine, 2-methyl-1, 5-pentylenediamine, 1, 3-cyclohexanediamine, 1, 2-diaminobutane, 1, 3-diaminobutane, 1-amino-3, 3, 5-trimethyl-5-aminomethylcyclohexane, 2-dimethyl-1, 3-diaminopropane, 1, 3-diamino-2, 2-dimethylbutane, 2, 4-diamino-1-methylcyclohexane, and mixtures thereof.

14. The process of claim 12 wherein the diisocyanate is 1-isocyanato-4- [ (4-isocyanatophenyl) methyl ] benzene, the molar ratio of diisocyanate to poly (tetramethylene-co-ethyleneether) glycol is from about 2.3 to about 17, and the chain extender is selected from the group consisting of ethylene glycol, 1, 3-propylene glycol, 1, 2-propylene glycol, 3-methyl-1, 5-pentanediol, 2-dimethyl-1, 3-propylene glycol, 2, 4-trimethyl-1, 5-pentanediol, 2-methyl-2-ethyl-1, 3-propanediol, 1, 4-bis (hydroxyethoxy) benzene and 1, 4-butanediol.

15. The process of claim 14, wherein the step of spinning to form spandex is a dry spinning step and the poly (tetramethylene-co-ethyleneether) glycol has a number average molecular weight of about 650 to about 4000 daltons.

16. A spandex comprising the reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) at least one diisocyanate;

(c) at least one chain extender selected from the group consisting of diamines and diols; and is

Wherein the spandex has an unload power at 100% elongation of at least 0.018 grams/denier.

17. A spandex comprising the reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) at least one diisocyanate;

(c) one or more diamine chain extenders; and is

Wherein the chain extender comprises one or more diamines and wherein the spandex has a retractive force at 100% elongation of at least 0.017 grams per denier and a load force at 100% elongation of less than 0.106 grams per denier.

18. A spandex comprising the reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) at least one diisocyanate;

(c) one or more diamine chain extenders; and is

Wherein the chain extender comprises one or more diamines, and wherein the spandex has a retractive force at 200% elongation of at least 0.0341 g/denier and a load force at 200% elongation of less than 0.16 g/denier.

19. A spandex comprising the reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) at least one diisocyanate;

(c) one or more diamine chain extenders; and is

Wherein the chain extender comprises one or more diamines, and wherein the spandex has a retractive force at 200% elongation of at least 0.0341 g/denier and a load force at 300% elongation of less than 0.227 g/denier.

20. A spandex comprising the reaction product of:

(a) a poly (tetramethylene-co-ethyleneether) glycol containing constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide wherein the portion of the units derived from ethylene oxide is present in the poly (tetramethylene-co-ethyleneether) glycol from about 16 to about 70 mole percent;

(b) at least one diisocyanate;

(c) one or more diamine chain extenders; and is

Wherein the chain extender comprises one or more diamines, and wherein the spandex has a tenacity of at least 0.495 g/denier and a load force at 200% elongation of less than 0.16 g/denier.