Europäisches Patentamt *EP000791085B1* (19) European Patent Office Office européen des brevets (11) EP 0 791 085 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) Int Cl.7: D01F 6/70, D01F 1/10, of the grant of the patent: C08K 3/26, C08L 75/04 02.11.2000 Bulletin 2000/44 (86) International application number: (21) Application number: 96930622.4 PCT/US96/13877 (22) Date of filing: 29.08.1996 (87) International publication number: WO 97/09473 (13.03.1997 Gazette 1997/12) (54) SPANDEX CONTAINING A HUNTITE AND HYDROMAGNESITE ADDITIVE SPANDEX ENTHALTEND EIN ADDITIV AUS HUNTIT UND HYDROMAGNESIT SPANDEX CONTENANT UN ADDITIF A BASE DE HUNTITE ET D’HYDROMAGNESITE (84) Designated Contracting States: (56) References cited: DE FR GB IT EP-A- 0 489 395 EP-A- 0 719 807 US-A- 4 525 420 (30) Priority: 07.09.1995 US 518148 • DATABASE WPI Section Ch, Week 8436 Derwent (43) Date of publication of application: Publications Ltd., London, GB; Class A25, AN 27.08.1997 Bulletin 1997/35 84-223080 XP002021175 & JP,A,59 133 248 (ASAHI CHEMICAL IND KK) , 31 July 1984 cited (73) Proprietor: E.I. DU PONT DE NEMOURS AND in the application COMPANY • DATABASE WPI Section Ch, Week 9303 Derwent Wilmington Delaware 19898 (US) Publications Ltd., London, GB; Class A25, AN 93-024136 XP002021176 & JP,A,04 352 844 (72) Inventor: CARNEY, Thomas, Edward (ASAHI CHEM IND CO LTD) , 7 December 1992 Waynesboro, VA 22980-9801 (US) (74) Representative: Woodman, Derek Frank B. Dehn & Co., European Patent Attorneys, 179 Queen Victoria Street London EC4V 4EL (GB) Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). EP 0 791 085 B1 Printed by Jouve, 75001 PARIS (FR) EP 0 791 085 B1 Description BACKGROUND OF THE INVENTION 5 Field of the Invention [0001] This invention relates to a spandex in which a mineral additive is dispersed. More particularly, the invention concerns such spandex wherein the mineral additive is a mixture of huntite and hydromagnesite. The spandex of the invention has in combination decreased tackiness, increased resistance to chlorine-induced degradation, good oper- 10 ating continuity in dry spinning and satisfactory retention of the mineral additive during scouring and dyeing operations. Description of the Prior Art [0002] Spandex is defined generically as a manufactured filament or fiber in which the fiber-forming substance is a 15 long chain synthetic polymer composed of at least 85% by weight of a segmented polyurethane. Usually spandex yarns are very elastic, but spandex yarns are also quite tacky compared to conventional "hard" fibers, such as of nylon or of polyester. The physical properties of spandex also are known to be detrimentally affected by exposure to chlorinated water, as for example in swimming pools. [0003] Various methods have been suggested for ameliorating the problems associated with the high tackiness and 20 low chlorine resistance of spandex elastic yarns. Some of the methods involve dispersing certain inorganic pigments in the spandex. For example, Goodrich et al, PCT application publication WO94/29,499, discloses that in addition to employing lubricating oils on the surface of the spandex, tackiness is further decreased by incorporating certain kinds of barium sulfate particles into the spandex. Martin, United States Patent 4,340,527, discloses dispersing high purity, finely divided particles of zinc oxide in spandex to reduce chlorine-induced degradation. Dispersion of various carbon- 25 ates, silicates, sulfates and oxides of group IIA metals in spandex is disclosed by Imai et al, U. S. Patent 4,525,420, to improve the resistance of spandex to chlorine-induced deterioration. Japanese Patent Application Publication No. 59-133248 (Morifuji et al) and European Patent Application 0 489 395 (Ido et al) disclose that addition of oxides or hydroxides of magnesium, zinc or aluminum or hydrocalcite compounds of MgxAly(OH)2 to spandex improves the resistance of the spandex to chlorine-induced deterioration. The incorporation of various inorganic particles into span- 30 dex as pigments or delustering agents is disclosed in Bell et al, United States Patent 3,389,942. [0004] Although the incorporation of the aforementioned inorganic particles into spandex is disclosed to provide certain positive effects, the particles also often cause certain problems. For example, the particles can plug filters and screens required in dry-spinning of the spandex and result in excessive interruptions in spinning continuity. Also, when incorporated in the spandex, the abrasiveness of the particles can cause excessive wear in parts of equipment typically 35 used to incorporate spandex into fabric, for example, guides and knitting neeedles. In addition, some of the particles can be leached or extracted from the spandex by conventional acid scouring and dyeing operations and result in unwanted chemicals entering the effluent streams of textile plants as well as reduced effectiveness in the protection the particles were intended to provide. Accordingly, it is an object of the present invention is to provide a suitable additive for spandex that would avoid the above-recited shortcomings and still provide the spandex with decreased 40 tackiness and increased resistance to chlorine-induced degradation. SUMMARY OF THE INVENTION [0005] The present invention provides a spandex filament or fiber in which the fiber-forming substance is a long chain 45 synthetic polymer composed of at least 85% by weight of a segmented polyurethane containing an effective amount of a physical mixture of huntite and hydromagnesite mineral particles dispersed within the spandex. The mineral mixture is effective in decreasing the tackiness of the spandex and increasing the resistance of the spandex to chlorine-induced degradation. Typically, the mineral mixture is present in a concentration in the range of 1.5 to 5% of the weight of the spandex , though somewhat higher or lower concentrations sometimes can be employed effectively. Preferably, the 50 concentration is in the range of 2 to 4%, based on the weight of the spandex. Typically, the mixture of huntite and hydromagnesite comprises at least 35 weight percent huntite, preferably 50 to 95 weight percent huntite. [0006] The present invention also provides a process for dry spinning spandex from a solution of a polyurethane polymer in a solvent for the polyurethane, wherein the process comprises 55 forming a concentrated slurry of a mixture of huntite and hydromagnesite particles in a solvent, and optionally other conventional particulate and non-particulate additives, the particles amounting to 10 to 40% of the total weight of the slurry, milling the concentrated slurry to break up particle aggregates and agglomerates and to decrease the median 2 EP 0 791 085 B1 particle size to less than 1 micron (1 x 10-6m), preferably to less than 0.5 microns (5 x 10-7m). incorporating the concentrated slurry into a polyurethane solution in an amount sufficient to provide a mixture of huntite and hydromagnesite particles amounting to 1.5 to 5% of the weight of polyurethane polymer, and dry spinning the solution into filaments. 5 DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS [0007] The following descriptions of preferred embodiments are intended to further illustrate the invention, but are not intended to limit its scope. The scope is defined by the appended claims. 10 [0008] For convenience, in the discussion and examples that are presented below, the following abbreviations may be used for the accompanying term: PO4G Poly(tetramethyleneether)glycol. MDI Methylene-bis(4-phenylisocyanate). 15 NCO Isocyanate end group. EDA Ethylenediamine. MPMD 2-methyl-1,5-diaminopentane. HMPD 1,3-diaminocyclohexame, also called hydrogenated m-phenylenediamine. 20 DMAc N,N-dimethylacetamide solvent. DEA Diethylamine. Cyanox® 1790 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethyl-benzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)trione antioxidant, sold by Cytec Industries. "Methacrol" 2462B Polyurethane of t-butyldiethanolamine and 4,4'-methylene-bis(cyclohexylisocyanate), made 25 by E. I. du Pont de Nemours & Co. Silicone oil A silicone oil of 96% poly(dimethylsiloxane) and 4% poly(diamylsiloxane). KP-32 Anthraquinone dye (toner) sold by Sandoz. [0009] The chemical composition of a polymer for the spandex also may be abbreviated. For example, a polyurethane 30 made from a poly(tetramethyleneether)glycol ["P04G"] having a number average molecular weight of 1800, methylene- bis(4-phenylisocyanate) ["MDI"] and a mixture of ethylene diamine ["EDA"] and 2-methyl-1,5-diaminopentane ["MP- MD"] in a molar ratio of 90 to 10, may be abbreviated as: PO4G(1800):MDI:EDA/MPMD(90/10). Note that colons separate the monomers of the repeating units of the polymer, a slash (i.e., /) between the diamines 35 indicates that the diamines are in a mixture and parenthetic numbers immediately following the glycol and diamine mixture respectively, refer to the number average molecular weight of the glycol and the molar ratio of the diamines in the mixture. [0010] In the descriptions and Examples that follow, various minerals are discussed. The art typically ascribes the following chemical compositions to the particular minerals discussed herein: 40 huntite Mg3Ca(CO3)4. hydromagnesite basic magnesium carbonate, usually written as Mg4(CO3)4·Mg(OH)2·4H2O. dolomite CaMg(CO3)2. 45 calcite CaCO3. magnesite MgCO3. Each of the above-listed minerals generally is considered to be a non-hazardous material in effluent streams. [0011] In accordance with the present invention, the spandex is formed from a polyurethane polymer that has dis- 50 persed within the polymer an effective amount of a particles of a mineral mixture of huntite and hydromagnesite.