Method for improving foam cell retraction behavior of thermoplastic elastomer microcellular foam material

Abstract

The invention relates to a method for improving the cell retraction behavior of a thermoplastic elastomer microcellular foam material, and belongs to the field of thermoplastic elastomer microcellularfoaming. The method for inhibiting the cell retraction of the thermoplastic elastomer microcellular foam material is characterized in that nanoparticles are introduced in the process of preparing thethermoplastic elastomer microcellular foam material, and the nanoparticles and the thermoplastic elastomer have a physical bonding or chemical crosslinking effect, thereby inhibiting cell retractionafter foaming of the foam material. The invention aims to provide the method for conveniently and efficiently improving the cell retraction behavior of the thermoplastic elastomer from the perspectiveof a molecular chain, and the problem of cell retraction of the thermoplastic elastomer is fundamentally solved.

Description

technical field [0001] The invention relates to a method for improving the cell retraction behavior of thermoplastic elastomers such as thermoplastic polyurethane microcellular foaming materials, and belongs to the field of thermoplastic elastomer microcellular foaming. Background technique [0002] Thermoplastic elastomers such as thermoplastic polyurethane (TPU) use carbon dioxide (CO 2 ) foaming method to prepare the microporous foam material, which has excellent shock absorption and resilience performance and wear resistance, and is widely used in shoe material production and tire preparation; the most representative ones are German Adidas and BASF companies The jointly developed Boost series of running shoes, for the first time, applied the infinergy of TPU foam particles in the production and preparation of the midsole of running shoes; the sole of this kind of running shoes not only has excellent shock absorption and resilience performance and wear resistance, but als...

AI Technical Summary

Problems solved by technology

However, during the molding process of TPU microcellular foamed materials, we found that there is an obvious phenomenon of unstable cell structure in the process of cell setting: the foaming ratio of the material drops sharply in a short time after the pressure relief is completed, and the cell setting Difficult, the cell shrinkage is serious; resulting in the increase of the density of the TPU foam material and the decrease of the expansion ratio, which greatly limits the performance and application fields of the TPU microcellular foam material

[0003] In response to this problem, most manufacturers of TPU microcellular foaming materials now use secondary foaming technology to improve the shrinkage behavior of TPU cells: at room temperature, the TPU foaming material obtained by the first foaming is made at a pressure of 4 -After fully swollen in a gas atmosphere of 5 atmospheres, the temperature is quickly raised above the softening point of the material; the swollen gas expands under high temperature, which provides the driving force for cell growth, promotes the secondary growth of cells, and reduces TPU The density of the foam material; however, this technology is cumbersome, the molding cycle is long, and the technical requirements for the equipment are high, which cannot meet the production needs of small and medium-sized enterprises.

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