Tanabata approaching, this is an old convention, is in Magpie Bridge cowherd day. This day is full of warmth and romance, love for Valentine's Day because more worth the wait and blessing! Now in advance I wish you happy Tanabata Festival Ha! In this wonderful day, small series is delivered to your mood rainbow colors - PP masterbatch.

PP masterbatch mainly by the pigment, dispersant, polymer carrier composed of three parts. So the problem here? PP masterbatch What are the requirements in raw material selection areas? Then Xiaobian to see what it:

PP masterbatch material selection three requirements:

1, Pigment

Masterbatch production and polypropylene spinning the pigment particle size requirements must be 1um less crude fiber floc particle size and general plastics in 5 ~ 10um. Ring-shaped fiber that can withstand the processing of various physical and chemical influence. Pigment chosen must be stable does not decompose at a spinning temperature conditions. While pigment does not have an adverse effect on polypropylene.

This is mainly reflected in two aspects:

(1) a pigment or pigment intermediates radical decomposition, the polymer of an α H off, free-radical initiated polymerization reaction;

(2) the pigment contained in the metal or metal salt leads to thermal oxidation degradation of the polypropylene. Also pigment must also have resistance to weather and the wet fastness (alkali treatment, water treatment), easy to disperse and other basic properties.

According to the requirements of alternative pigments inorganic pigments and organic pigments two categories. Different pigments for masterbatch formulation process have different requirements. Such as inorganic pigments, pigment grinding system must be configured. If the solvent phase should also consider the question to the grinding phase. Organic pigments, especially the oil-soluble pigment can be well dissolved in the dispersant, the polishing system can be omitted.

Pigment to dispersant ratio requirements are also different:

(1) inorganic pigment surface area is small, the amount of dispersant is small, the ratio is 60: 40.
(2) an organic pigment large surface area, the amount of dispersant is large, the ratio is 40: 60.

Pigments of polypropylene fiber-forming also have an impact, mainly in the melt rheological properties, filtration properties, crystallization behavior and Qi fiber processing performance aspects. Also pointed out that mixing pigment and polypropylene is a heterogeneous system. Mixing the viscous resistance is large, in the processing must ensure sufficient mixing valve and shear forces.

2, a dispersing agent

MBKa3aNKOB and so that added to the general dispersant in the thermoplastic polymer masterbatch and compatible polymer due to bad will affect the spinning properties of the polymer, it is best to use the polymer itself open as a sub-agent. Optional low molecular weight polymer or oligomer. As PP masterbatch with sub-agents taught abroad generally low molecular weight polyethylene (polyethylene wax), it can not only increase the entropy Wen Yan debate particle repulsion preventing pigment flocculation in the polymer, and can improve the polymer melt body flow properties, improved spinnability.

In addition, as dispersants there are many anionic surfactants help. Anionic surfactants may also be employed. In order to give full play to the characteristics of various dispersants on the literature suggests that the effect is more ideal mix. If only in order to provide a repulsive force from the dispersion entropy, as long as the dispersant added a very small amount, and polypropylene for good mixing and dispersing agent must be a certain amount or more, in the masterbatch is generally added in an amount of 1/3 of the polypropylene.

3, polymer carrier

Carriers should use some and polypropylene polymers have good compatibility. Lower melting point than the spinning resin 20 ~ 30 ℃, it not only does not affect the quality of the product but also has anti-flocculation of pigments. At the same time, having a good dispersibility (i.e., a pigment concentrates to dilute the resin distribution properties of the resin). PP masterbatch carrier often used polyolefins can be used are: molecular weight of 1.5 to 20,000 high-pressure polyethylene, low-pressure polyethylene or polypropylene melt index of 20.

It is because of the strict requirements, only the achievements of high quality. PP masterbatch in the production process, must be based on the above three criteria Oh!