High-elastic TPU thin film and preparation method thereof

Abstract

The invention relates to a high-elastic TPU thin film and a preparation method thereof. The method includes: according to ratio, performing three-stage mixing on prepared TPU granules, foamed siliconemaster batches, and modified nano-SiO2 master batches; feeding the mixture to a casting machine through an automatic conveying system; and extruding the mixture to form the thin film. The TPU thin film is high in elasticity and can be widely applied to the fields, such as: damping materials, packaging and toys, children's toys, sports equipment, aero-models, heat insulation materials, and automobile trim materials, etc.

Description

technical field [0001] The invention relates to the technical field of thermoplastic polyurethane elastomers, in particular to a high-elastic TPU film and a preparation method thereof. Background technique [0002] Thermoplastic polyurethane elastomer (TPU) is a kind of heat-plasticized and soluble polyurethane material, which has a unique structure of soft and hard block copolymers. It is widely used because it has both the elasticity of rubber and the processability of plastic It is used in many fields, such as: exterior parts of automobile body, cable sheath, adhesive tape, ski boots, gear, rubber hose, clothing fabric, inflatable products, etc. [0003] Usually, different application fields have higher requirements for TPU materials in certain aspects, such as: clothing and shoe materials require TPU fabrics to have better waterproof and moisture permeability, mechanical equipment requires TPU products to have higher mechanical strength, and inflatable products ( Such a...

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Problems solved by technology

[0007] Disclosed in CN103408922A and CN102276785A TPU foaming material preparation process, take TPU as matrix, obtain TPU foaming material by adding auxiliary agents such as chemical foaming agent, crosslinking agent and auxiliary crosslinking agent, foaming process is similar to EVA foaming , there are also problems of cross-linking and environmental protection. In addition, the use of chemical blowing agents will make the cell structure inhomogeneous, and incompletely decomposed chemical blowing agents are harmful to the human body and material properties; WO2010136398A1 uses CO 2 , N 2 The inert gas is used as the foaming agent, and the low-density TPU foamed beads are obtained by the suspension method

And this method also has the following disadvantages: the suspension method uses water as the medium. As we all know, TPU is relatively poor in hydrolysis resistance, especially for polyester TPU. The suspension method needs to be boiled in hot water at 100-140°C for 2 hours , this kind of high-temperature and long-term water boiling is easy to degrade TPU, which leads to a decrease in the performance of TPU after foaming; on the other hand, the TPU particles after blending contain small molecular substances, such as: pigments, anti-aging agents, fillers etc. These small molecular substances are easily precipitated from the particles or migrated to the surface after being boiled in hot water for a long time, which leads to a series of problems in TPU foamed particles.

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