Spandex for paper diapers with improved unwinding and creep properties and production method thereof

Abstract

The invention discloses a spandex with improved backing-off property and creep property for a paper diaper and a production method thereof. Thermoplastic polyurethane which accounts for 3-35% of the spandex by weight percent and cellulose acetate butyrate or cellulose acetate propionate which accounts for 0.5-2.0% of the spandex by weight percent or a mixture of the two, as well as an internal lubricant and external lubricant composition which accounts for 0.3-5.0% of the spandex by weight percent, are added into a polyurethane-urea stock solution, and drying spinning is performed to prepare a polyurethane elastic fiber, wherein an internal lubricant is one or more of n-butyl stearate, oleamide, ethylene bis stearamide and amino silicon oil; and an external lubricant is one or more of talcum powder, carbon monofluoride and magnesium stearate. The prepared spandex has favorable backing-off property and creep property, can be effectively applied to the field of elastic materials of paper diapers, and meanwhile, is suitable for two modes of rotary backing off and axial backing-off.

Description

technical field [0001] The present invention relates to spandex for paper diapers with improved unwinding and creep properties and a production method thereof. Specifically, the spandex prepared by the invention has excellent unwinding properties and creep properties, can be effectively applied in the field of elastic materials for diapers, and is suitable for both rotary unwinding and axial unwinding. Background technique [0002] Spandex, that is, polyurethane elastic fiber, has gradually replaced traditional rubber root as an elastic material for diapers due to its excellent elastic function, but conventional spandex has 2% to 10% weight of oil attached to the surface. On the one hand, although the attached oil agent is conducive to the smooth unwinding of spandex yarn, on the other hand, it seriously hinders the adhesion performance (ie creep) of spandex yarn and hot melt adhesive, and the oil agent content is too high. If it is too much, it will pollute the diapers and...

AI Technical Summary

Problems solved by technology

In addition, in order to pursue the feeling of wearing, spandex for diapers generally requires a higher constant elongation stress, especially in the field of adult diapers, because the low constant elongation stress will lead to poor fixation - too loose, when the urine is wet, The entire diaper will fall or even fall off, and it will cause side leakage, which greatly affects the wearability of the diaper product; but if the constant elongation stress is too high, it will cause tight fixation, a sense of pressure, and red marks on the skin, especially for baby diapers. field not applicable

[0003] The spandex elastic fiber prepared by the patent CN103422189A does not contain silicon elements, because the conventional oil contains a large amount of silicone oil, which helps to improve the unwinding property, but reduces the creep property. Bonding can greatly reduce the slippage of fibers on the non-woven fabric, but its creep property is not ideal, and the constant elongation stress of spandex is low, and the friction coefficient between fibers is large, which is not conducive to axial Unwind

Patent CN105008602A adds ethylene-vinyl acetate monomers, polymers and derivatives thereof, or hydrocarbon resin monomers, polymers and derivatives thereof with 9 carbon atoms, or hydrocarbon resins with 5 carbon atoms, to the spinning dope Atomic hydrocarbon resin monomers, polymers and their derivatives, or C5 / C9 hydrocarbon resin monomers, copolymers and their derivatives and other tackifiers are prepared to improve the adhesion properties with hot melt adhesives Although the spandex fiber has excellent adhesive properties, when preparing the spinning dope, the dissolving uniformity of these tackifiers is not good, and the compatibility with polyurethane is not good, which affects the production stability and product uniformity. Moreover, these tackifiers will reduce the original elastic function of the product, and at the same time, the adhesion effect between fibers is obvious, which is not conducive to rotary unwinding

Patent CN102362020A adds modified cellulose to polyurethane or polyurethane urea stock solution to improve the anti-sticking effect and unwinding uniformity of the product, but the creep property of the product is not good enough, and too much modified cellulose is added to the spinning stock solution After medium concentration, it will seriously reduce the breaking strength of spandex and affect product performance, and too little content will not reflect the anti-sticking effect

[0004] The unwinding and creep properties of spandex have an important impact on the production efficiency and quality of diapers. On the one hand, poor unwinding performance will not only lead to downtime, but also cause a large number of diapers to be discarded. The hot melt adhesive at 190°C can effectively bond the spandex fiber to the non-woven fabric substrate. Too poor creep will affect the elastic function of the diaper, which in turn will affect the normal use of the diaper

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