Method for producing functional nylon-6 slice

Abstract

The invention relates to a method for producing a functional nylon-6 slice. The method comprises the following steps of: (a) dispersing functional powder in liquid caprolactam to form a functional powder dispersion liquid; (b) metering the functional powder dispersion liquid by using a liquid pump and conveying the dispersion liquid to an extruder; (c) metering a product polymerized with a conventional hydrolysis and ring-opening polymerization method by using a melt pump and conveying the product to the extruder; (d) extruding and granulating after the functional powder dispersion liquid of the step (b) and the polymerized product of the step (c) are mixed by the extruder; and (e) extracting and drying granules to prepare a product. Compared with a traditional mode, the invention has the advantages of flexible production variety switching, less production change consumption, fine granularity and good dispersity of the functional powder in the chip product, low degradation of nylon molecule and stable quality.

Description

technical field [0001] The invention relates to a production method of functional nylon 6 chips, belonging to the field of nylon 6 production. Background technique [0002] At present, many downstream products of nylon 6, including silk, film and plastic, can be functionalized by adding functional ingredients, such as antibacterial, antistatic, far-infrared emission, anti-ultraviolet, coloring, etc. The most common method is to first Part of the nylon 6 resin is made into a masterbatch, which is added and mixed during molding (spinning, injection molding, extrusion). Antibacterial agents and far red powder are mainly added in this way. Also, it is added before polymerization. Typical additives include titanium dioxide used as a matting agent. Certain varieties such as fabrics can also be surface treated (including dyed) to add functionality. [0003] The masterbatch method has the advantages of being simple, convenient, easy to replace, easy to clean, and has good dispersi...

AI Technical Summary

Problems solved by technology

In the downstream use, if masterbatch is used, especially in the production of fibers with high requirements, it is often necessary to modify the conventional production equipment and install more expensive metering injection equipment.

If the blending of masterbatch and chips is used, there will be disadvantages such as uneven mixing and layering.

[0004] The continuous polymerization method of nylon 6 currently used is to add additives before polymerization, and the functional chips produced by the method of polymerization addition are easy to disperse the additives evenly, and do not need to be reprocessed by the screw, but its limitations are relatively large. The requirements for raw materials are extremely high when adding them. It is required that the raw materials added at this time must withstand a high temperature of at least 270°C and a hydrolysis environment. It is also required that there will be no catalytic side reactions in the polymerization reaction.

The longer polymerization reaction time also requires that the reactant is a very stable suspension, otherwise agglomeration and sedimentation will occur, so there are few additives available, and the current continuous production device has a huge capacity, and there are many raw materials and melt pipelines. Varieties require long-term transitional cleaning, consume a large amount of raw materials, and greatly increase costs. Therefore, the actual products produced are only full-dull, semi-dull, and glossy slice varieties, and functional slices with various varieties and relatively small demand almost impossible to produce

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