White master batch applied for polyolefin film and preparation method thereof

Abstract

The invention discloses a white master batch applied to a polyolefine film and a preparation method thereof. The white master batch consists of 20 to 75 percent of a white pigment and 25 to 80 percent of a polyethylene resin, wherein, the white pigment is one or a plurality of titanium pigment, zinc oxide, rubberlith, limestone powder and talcum powder. The white pigment and the polyethylene resin are mixed in a banbury mixer, the mixing temperature is between 115 and 190 DEG C, the pressure is between 0.5 and 1.0MPa and the white master batch is produced after the pelleting process. The white master batch does not have any organic dispersing auxiliary, and the coloured master batch product with high concentration, high dispersing property, small dosage and even coloration is produced by selecting appropriate mixing temperature according to different mixing system compositions.

Description

Technical field: [0001] The invention relates to a color masterbatch used in plastic processing, in particular to a white masterbatch applied to polyolefin films and a preparation method thereof. technical background: [0002] Color masterbatch is often used in plastic production and processing to color it, among which polyolefin white masterbatch is the most important and widely used one. The existing polyolefin white masterbatch is made of colorants, carriers, dispersing aids, etc., and the colorants used are generally titanium dioxide. For example: Chinese patent application No. 02135591.6 discloses a technology for preparing high-density polyolefin white masterbatch, by adding pigments, plastic additives and carrier resins into a high-speed mixer and mixing them, and then adding a coupling agent and liquid paraffin mixture to stir, Then extrude through twin-screw extruder to prepare white masterbatch. The content of the pigment (titanium dioxide) in the obtained white ...

AI Technical Summary

Problems solved by technology

[0003] Because titanium dioxide is easy to aggregate into agglomerates, its dispersion effect is not good, so it is necessary to add dispersion system additives to the white masterbatch to meet the dispersion requirements of the color masterbatch

Due to the addition of low-molecular additives, the cost of masterbatch raw materials is increased, and because the additives in the dispersed system in the masterbatch are low-molecular organic substances, the existence of these low-molecular organic substances will affect the final use of the product, such as film-forming properties, Printing performance, when the product is used in production, there will be powder precipitation after a period of time, which is the so-called powdering phenomenon, resulting in poor appearance of the product

It is especially used in food packaging films. Due to the continuous migration and precipitation of organic additives from the inner layer of the film, it will pollute the packaged food and is not conducive to human health.