Thermoplastic polyurethane elastic fiber and preparation method thereof

Abstract

The invention discloses a thermoplastic polyurethane elastic fiber and a preparation method thereof. From small molecule diol and diamine mixture. The present invention forms a mixed chain extender by introducing a certain amount of diamines with a nitrogen-containing heterocyclic structure and small molecular diols into the TPU molecular structure. Compared with other TPU elastic fiber materials containing conventional aromatic diamines, the present invention can Bonding can be carried out at a lower temperature, and at the same time, it can effectively improve the spinnability of the material and improve the resilience.

Description

technical field [0001] The invention relates to a thermoplastic polyurethane and a preparation method thereof, in particular to a thermoplastic polyurethane elastomer which can be melt-spun at low temperature. Background technique [0002] The preparation of thermoplastic polyurethane (TPU) elastic fibers includes dry spinning (dry spinning), wet spinning (wet spinning), melt spinning (melt spinning) and other methods, among which dry spinning is the most common method, but in the production of TPU Volatile solvents need to be added in the fiber process, which will pollute the environment to a certain extent. At the same time, the operation process of recovering the solvent also increases the production cost. If the solvent does not volatilize, it will have a health impact on the human body during use and wearing. In recent years, since melt spinning does not use solvents, it will not cause pollution to the environment, and the investment in product equipment is low, so ther...

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Problems solved by technology

[0002] Preparation of thermoplastic polyurethane (TPU) elastic fibers has methods such as dry spinning (dry spinning), wet spinning (wet spinning), melt spinning (melt spinning), among which dry spinning is the most common method, but in the production of TPU Volatile solvents need to be added in the fiber process, which has certain pollution to the environment. At the same time, the operation process of solvent recovery also increases the production cost. If the solvent is not volatile, it will cause health effects on the human body during use and wearing.

In recent years, since melt spinning does not use solvents, does not pollute the environment, and has less investment in product equipment, more and more research has been done on the preparation of TPU elastic fibers by melt spinning. However, the spinnability and low temperature processability of melt spinning TPU fibers are currently , and fiber rebound rate are not satisfactory

[0003] Patent CN99108972.3 proposes a manufacturing method of TPU fiber, using polyether polyol and polyester polyol as intermediates, and introducing small molecule aliphatic diol and aliphatic diamine into the TPU structure to increase the urea bond content of TPU , improve the spinnability of the material, but reduce the resilience and softness to a certain extent. In addition, the addition of aliphatic diamine increases the difficulty of the process, resulting in inconsistent product quality

Patent CN200610084136.0 reports a TPU that can be processed into film or fiber at the same time, using conventional diisocyanate, two kinds of hydrophobic and hydrophilic polyols (polytetramethylene ether glycol, propylene oxide polyol) , and a mixed chain extender of low molecular weight diol and aromatic diamine (trimethylene glycol di-p-aminobenzoate) as the main raw material, although the aromatic diamine improves the resilience of the fiber, but its processing The temperature is high and the processing range is narrow, which increases the difficulty of melt spinning processing, and the uniformity of the obtained fibers is poor

Patent CN200710170876.0, which is relatively similar to patent CN200610084136.0, improves fiber hardness and tensile strength by introducing an appropriate proportion of soft segments of silicone containing silicon-oxygen bonds and hard segments of aromatic diamines that can form urea bonds into TPU. , rebound rate and other properties, and the introduction of aromatic diamines will also make spinning difficult, and the addition of soft segments containing silicon-oxygen bonded silicones has not brought significant improvement in material performance

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