| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | November 9, 1999 |
| PATENT TITLE |
Spandex made with 1,3-diaminopentane |
| PATENT ABSTRACT | A polyurethaneurea polymer and spandex spun therefrom, based on polymeric ester or ether glycols and MDI at certain capping ratios, and 1,3-diaminopentane chain extender, are provided |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | March 26, 1998 |
| PATENT CLAIMS |
I claim: 1. A polyurethane polymer comprising the product of a polyether glycol selected from the group consisting of a homopolymer of tetrahydrofuran (THF) and a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran (3-MeTHF); 1'1-methylenebis(4-isocyanatobenzene); and diamine chain extenders wherein one diamine is 1,3-diaminopentane (1,3-DAP) present to an extent of 35-90 mole % of the mixture of diamine chain extenders and the other diamine is ethylenediamine; wherein the range of molar ratios of said bis-isocyanate to said glycol is determined as follows: ______________________________________ 1,3-DAP capping ratio ______________________________________ homopolymer of THF 5-<50 1.50-1.90 .gtoreq.50-90 1.60-2.50 copolymer of THF 5-<50 1.65-2.50 and 3-MeTHF .gtoreq.50-90 2.20-3.70. ______________________________________ 2. The polymer of claim 1 wherein the polymeric glycol is a homopolyether of tetrahydrofuran. 3. The polymer of claim 1 wherein the polymeric glycol is a copolyether of tetrahydrofuran and 4-20 mole %, based on the polymeric glycol, of 3-methyltetrahydrofuran. 4. The polymer of claim 1 wherein 1,3-diaminopentane is present to an extent of at least about 60 mole % of the diamine chain extenders. 5. A spandex spun from the polyurethaneurea polymer of claim 1. 6. A polyurethane polymer comprising the produce of a polyester glycol selected from the group consisting of a copolyester of ethylene glycol and butylene glycol with adipic acid and a polyester of 2,2-dimethyl-1,3-propane diol and 1,12-dodecanedioic acid; 1,1'-methylenebis(4-isocyanatobenzene); and diamine chain extenders wherein one diamine is 1,3-diaminopentane present to an extent of 35-90 mole % of the mixture of diamine chain extenders and the other diamine is ethylenediamine; wherein the molar ratio of said bis-isocyanate to said glycol is 1.5-3.7. 7. A spandex spun from the polyurethaneurea polymer of claim 6. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to new polyurethaneureas and spandex made therefrom and, more particularly, to polyurethanureas which have been chain-extended with 1,3-diaminopentane. 2. Description of Background Art 1,3-Diaminopentane has recently become commercially available. No prior disclosure of its use in making spandex is known. Japanese Published Patent Application No. 03-279415 (1991) discloses the use of asymmetric diamines at levels of up to 30 mole % in mixtures with symmetrical diamines to provide good solution viscosity stability. U.S. Pat. No. 5,472,634 to Hart, discloses the use of 1,3-diaminopentane in an amount of 15-30 mole % of the total chain extenders to make water-based polyurethaneurea dispersions for coatings. SUMMARY OF THE INVENTION The composition of the present invention is a polyurethaneurea polymer based on: a polymeric glycol selected from polyether glycols and polyester glycols wherein the polyether glycol is selected from the group consisting of a homopolymer of tetrahydrofuran (THF) and a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran (3-MeTHF); 1,1'-methylenebis(4-isocyanatobenzene); and diamine chain extender(s) wherein at least one diamine is 1,3-diaminopentane (1,3-DAP) present to an extent of at least 5 mole % of the mixture of diamines and the remainder is ethylenediamine; wherein the range of capping ratios depends on the amount of 1,3-DAP present in said mixture of diamines and on the type of glycol and is determined as follows: ______________________________________ 1,3-DAP capping ratio ______________________________________ homopolymer of THF 5-<50 1.50-1.90 .gtoreq.50-90 1.60-2.50 copolymer of THF 5-<50 1.65-2.50 and 3-MeTHF .gtoreq.50-90 2.20-3.70. ______________________________________ DETAILED DESCRIPTION OF THE INVENTION Fabrics or yarns which contain spandex and nonelastomeric fibers are typically treated with heat or steam to "set" the fabric or yarn. This gives the fabric or yarn good dimensional stability and shapes the finished garment. Good steam- and heat-set efficiency allows shorter setting times and/or lower setting temperatures. As a result, the setting process can be operated more economically, and fabrics and yarns can be set even if they contain fibers which will tolerate only lower temperatures. "Spandex", as used herein, has its customary meaning, that is, a manufactured fiber in which the fiber-forming substance is a long chain synthetic elastomer comprised of at least 85% by weight of a segmented polyurethane. The polyurethane is generally prepared by reacting a polymeric glycol with a diisocyanate to form an NCO-terminated prepolymer, or "capped glycol", dissolving the capped glycol in a suitable solvent such as dimethylacetamide ("DMAc"), dimethylformamide, or N-methylpyrrolidone, and reacting the capped glycol with one or more difunctional chain extenders. Polyurethaneureas are formed when the chain extenders are diamines. The molar ratio of diisocyanate to polymeric glycol is called the "capping ratio". A minor amount of monofunctional secondary amine such as diethylamine can be added with the chain extender to control molecular weight. The polymer solution can then be dry- or wet-spun to form spandex. It has now been found that 1,3-diaminopentane (1,3-DAP) can be used at a level of at least about 5 mole % with other diamine chain extenders to give spandex with improved properties which can be varied to suit the needs of the user by varying the level of 1,3-diaminopentane. It has been further found surprisingly that using 1,3-DAP at a level of at least about 35 mole %, with any remaining chain extender being ethylene diamine, gives spandex having superior steam- and heat-settability. Levels of at least about 60 mole % 1,3-diaminopentane are preferred, due to the higher steam- and heat-settability that can be attained. When another chain extender is used with 1,3-diaminopentane, that chain extender is ethylenediamine. In order to control the molecular weight of the polyurethane, minor amounts of primary and/or secondary monoamines can be added. Such chain terminator amines can generally be added as a mixture with the chain extenders. Diethylamine is preferred. Optionally, a minor amount of crosslinking can be provided by including a small amount of a trifunctional amine such as diethylenetriamine in the chain extender/chain terminator mixture. Suitable polymeric glycols for the practice of the present invention are polyester diols and polyether diols. The latter can be derived from tetrahydrofuran, 3-methyltetrahydrofuran, and copolymers thereof. When such a copolymer is used, the amount of 3-methyltetrahydrofuran present can be in the range of about 4-20 mole % and, preferably, in the range of about 10-15 mole %. Glycol-terminated polyesters are also useful for preparing the spandex of the present invention. These include the reaction products of ethylene glycol, tetramethylene glycol, butylenediol, diethylene glycol, and/or 2,2-dimethyl-1,3-propanediol and the like with diacids such as adipic acid, succinic acid, 1,12-dodecanedioic acid, and copolymers thereof. Polyester glycols derived from the ring opening of .epsilon.-caprolactone and .delta.-valerolactone can also be used. The polymeric reaction product of 2,2-dimethyl-1,3-propanediol with 1,12-dodecanedioic acid, which is poly(2,2-dimethylpropylene dodecanoate), and the copolymeric reaction product of ethylene glycol, butylenediol, and adipic acid, which is poly(ethylene-co-butylene adipate), are preferred. The diisocyanate used in this invention is 1,1'-methylenebis(4-isocyanatobenzene) (MDI). The capping ratios used in the present invention are in the range of about 1.5-3.7. The capping ratio is increased as the proportion of 1,3-diaminopentane in a mixture of chain extenders is increased. If the capping ratio is too low, the polyurethaneurea is difficult to spin into spandex. If the capping ratio is too high, the elongation-at-break of the spandex is too low. When the polymeric glycol is a homopolymer of THF and 1,3-diaminopentane is present to an extent of approximately 50-90 mole % of the total chain extender, the capping ratio is in the range of about 1.6-2.5. When the polymeric glycol is a copolymer of tetrahydrofuran and 3-methyltetrahydrofuran and 1,3-diaminopentane is present to an extent of approximately 50-90 mole % of the total chain extender, the capping ratio is in the range of about 2.2-3.7. The following test methods were used: Total isocyanate content of the capped glycols was measured by the method of S. Siggia, "Quantitative Organic Analysis via Functional Group", 3rd Edition, Wiley & Sons, New York, pages 559-561 (1963). The strength and elastic properties of the spandex were measured in accordance with the general method of ASTM D 2731-72, using an Instron tensile tester (Instron Corp., Canton Mass.). Three filaments, a 2-inch (5-cm) gauge length and a 0-300% elongation cycle were used for each of the measurements. The samples were cycled five times at a constant elongation rate of 50 cm per minute. Load power, the stress on the spandex during initial extension, was measured on the first cycle at 200% extension and is reported in millinewtons per tex. Unload power is the stress at an extension of 200% for the fifth unload cycle and is also reported in millinewtons per tex. Percent elongation-at-break was measured on a sixth extension cycle. To measure heat-set efficiency, the spandex samples were mounted on a 10-cm frame and stretched 3.5.times. (250%). The frame (with sample) was placed horizontally in an oven preheated to 190.degree. C., for 90 seconds. The samples were allowed to relax and the frame to cool to room temperature. The samples, still on the frame, were immersed in boiling water for 30 min. The frame and samples were removed from the bath and allowed to dry. The length of the yarn samples was measured and heat-set efficiency was calculated from the following equation: ##EQU1## Each sample was tested four times, and the results were averaged. To determine steam set, which is a measure that simulates hosiery processing and boarding operations, a sample of a chosen length in a straight non-tensioned condition, Yo, (conveniently 10 cm) was stretched to three times its original length for about 2 minutes and then relaxed. This simulated a covering operation in which the spandex was drafted while being covered with a conventional yarn. The thusly stretched and relaxed spandex test sample was then placed in a relaxed condition in a boiling water bath for 30 minutes. This exposure to boiling water simulates a dyeing operation. The sample was then removed from the bath, dried, and stretched to twice its post-bath relaxed length. While in this stretched condition, the sample was exposed for 30 seconds to an atmosphere of steam at 10 psig (69 KPa) 110.degree. C. The steam treatment simulates hosiery boarding. After removal from the steam atmosphere, the sample was allowed to dry, and its straight non-tensioned length, Yf, was measured. Steam set (%SS) was then calculated according to the formula %SS=100(Yf-Yo)/Yo. High percent steam set is a desirable characteristic. Solution viscosity was determined in accordance with the general method of ASTM D1343-69 with a Model DV-8 Falling Ball Viscometer (Duratech Corp., Waynesboro, Va.), operated at 40.degree. C. |
| PATENT EXAMPLES | available on request |
| PATENT PHOTOCOPY | available on request |
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