A kind of mixing method for preparing nitrile rubber/polyvinyl chloride alloy compound rubber by two-stage mixing

Abstract

The invention discloses a mixing method for preparing acrylonitrile-butadiene rubber / polyvinyl chloride alloy compound rubber by two-stage mixing. The first stage is temperature-rising mixing, and the second stage is cooling mixing, which specifically includes the following steps: Add nitrile rubber, polyvinyl chloride, PVC stabilizer and high-temperature adhesive additives to the first-stage internal mixer, and during the mixing process The rotational speed is controlled so that the shear heat generation is greater than the heat dissipation, and the heat is generated at the same time during mixing. After mixing until the temperature reaches the first-stage discharge temperature, the material is discharged; after discharge, the material is directly put into the second-stage internal mixer without cooling; The final refining aid is added to the second-stage internal mixer at the same time, and the rotating speed and cooling conditions are controlled so that the material is cooled at a certain cooling rate while mixing. When the material temperature reaches a certain temperature after mixing, the material is discharged, and the mixing is completed. Thin the flakes in the mill.

Description

A kind of mixing of two-stage mixing to prepare nitrile rubber / polyvinyl chloride alloy mixed rubber method technical field The present invention relates to the technical field of mixing rubber preparation technology of rubber-plastic alloy, particularly relate to a kind of NBR / PVC alloy The field of compound rubber preparation technology. Background technique [0002] NBR / PVC blends are widely used in the preparation of foamed products, such as thermal insulation boards, cushions for sporting goods, handles, etc. Wait. In this system, NBR can provide good elasticity and feel, while PVC can play the role of skeleton in the system, The whole foaming system has good operability and stable product quality; in addition, NBR and PVC are both polar high molecular polymers, which have Good compatibility, so its application is more and more widely. On the other hand, the melting point of PVC is higher, and when it is blended with NBR, it needs to have enough when PVC is m...

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Problems solved by technology

[0008] In the prior art, NBR / PVC compound rubber is generally mixed by two-step method, that is, NBR and PVC are mixed at high temperature first, and after being prepared into a blended rubber, other rubber additives are added after cooling, and then mixed. Discharge after reaching a certain temperature. This method has several obvious disadvantages. First, the energy consumption of mixing is very high. The preparation of the blend requires heating up. Adding rubber additives needs to be cooled before adding, and then heating up after adding. The two heating processes consume a lot of electric energy. The second is that the cooled NBR / PVC blend rubber has a high hardness, and re-mixing will cause a large loss of equipment, especially when the PVC content in the blend rubber is high. When the ratio of PVC and NBR exceeds 1:1, the operation of this method is more difficult and the loss of equipment is greater

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