Method for preparing thermoplastic vulcanized rubber

Abstract

The invention discloses a method for preparing thermoplastic vulcanized rubber and provides technology for preparing the thermoplastic vulcanized rubber by only using common rubber and plastic equipment. The common rubber and plastic equipment comprises a common rubber kneading machine and a heating temperature control system thereof, an open mill, a plastic crusher and a plastic extruder, wherein the temperature range of the heating temperature control system of the common rubber kneading machine is controlled to be between 100 and 220 DEG C; the blending process of the thermoplastic vulcanized rubber kneading machine comprises the following steps of: firstly pre-preparing rubber mixing glue; then blending the rubber mixing glue with the rubber kneading machine; and adding the mixture bysteps when the using amount of a softening agent or plastic is over 25 percent of the total capacity of mixing. The method creates a precedent of preparing the thermoplastic vulcanized rubber by using the common rubber and plastic equipment. The properties such as tensile strength, tear strength, dispersion, extrusion appearance and the like of the prepared thermoplastic vulcanized rubber are obvious better than those of the thermoplastic vulcanized rubber prepared by the prior art. Meanwhile, the method reduces equipment investment and production cost for TPV manufacturers.

Description

technical field [0001] The invention relates to the preparation technology of thermoplastic vulcanizate, in particular to a method for preparing thermoplastic vulcanizate by utilizing ordinary rubber and plastic equipment. Background technique [0002] As we all know, thermoplastic vulcanizate is a blended thermoplastic elastomer prepared by dynamic full vulcanization technology. When rubber and thermoplastic resin are melted and mixed, the rubber is completely chemically cross-linked "in situ" by means of a vulcanizing agent. Under the action of force, the cross-linked rubber is broken into a large number of micro-particles, which are dispersed in the continuous thermoplastic resin matrix to form a "sea-island" structure, thus becoming a thermoplastic vulcanizate, namely TPV (Theromoplastic Vulcanizate). The rubber used to prepare TPV usually includes: natural rubber, trans isoprene rubber, styrene-butadiene rubber, butadiene rubber, EPDM rubber, nitrile rubber, butyl rubbe...

AI Technical Summary

Problems solved by technology

[0004] To a certain extent, dynamic vulcanization technology is not very suitable for preparing thermoplastic vulcanizates with low hardness and high fluidity, because low hardness TPV is generally obtained by increasing the rubber content. With the increase of rubber content, the plastic matrix must form a continuous Phase becomes difficult and the prepared material becomes difficult to uniformly disperse and extrude

High-fluidity TPV is generally obtained by increasing the plastic content or using high-melting plastic materials. Increasing the plastic content will increase the fluidity of TPV, but the hardness and compression deformation of TPV will also increase, and the elastic properties will decrease. At the same time, the viscosity during melt blending will also decrease, and the use of plastics with high melting index will also reduce the viscosity during melt blending. When the viscosity is too low, it is not conducive to the shear dispersion of rubber, and even the rubber cannot be used. fully vulcanized

In addition, increasing the amount of softener can also reduce hardness and increase fluidity, but when the amount of softener is large, it will also affect the dispersion of TPV and the vulcanization of rubber

Therefore, the above problems are some difficulties in the preparation of TPV, no matter whether it is blended with an ordinary internal mixer or an ordinary twin-screw extruder to produce TPV. Although, these problems can be solved by using more advanced processing equipment, such as Germany The latest TPV production equipment produced by Berstorff, the countercurrent pump in the mixing can make the rubber and other components more uniformly dispersed, and the bypass feeding equipment and metering system are also introduced on the twin-screw extruder to facilitate vulcanization. The late addition of agent and late oil filling and other processes, but this requires the purchase of expensive TPV special production equipment

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