Zinc Stearate

Zinc Stearate is obtained from stearic acid. It is fine, white and silky to the touch, with the following properties:

It is very stable under high temperature conditions.
It is highly water resistant, giving repellent properties.
It is extremely resistant to water and provides water-repellent properties.
It is a very effective separating agent.
It serves as a supply of zinc, which is a benefit in some processes.

Vulcanized Rubber

Zinc stearate is an “activator” for vulcanization because zinc has a beneficial effect on the reaction of sulphur with polyolefin.

Zinc stearate facilitates dispersion by being very soluble in the apolar region of polyolefins.

It works as an antacid with polyolefins, contributing to colour stability and preventing corrosion.

Cosmetics

Zinc stearate is used as a lubricant, thickener, and to hold together the liquid and oily elements in cosmetics. It also improves the final appearance of the product.

It usually appears in make-up formulations such as eyeliner, eye shadows, facemasks, lipsticks, face powders and foundation creams. Zinc stearate does not cake; it flows very well and adds a silky touch to the mix.

Separating Agent for Metalurgy

It is an ideal separating agent for difficult machine parts, whether metal or plastic. It prevents the parts from adhering to the mould, leaving a better finish.

Varnishes and Paints

In its finest form, zinc stearate has transparent properties and is used in the manufacture of varnishes and paints.

It provides great dispersal ability and acts as a sealer for imperfections on the surface and as a thickener. In addition, it protects the paint from moisture due to its water-repelling properties.

Sinterizing – Powder Metalurgy

Zinc stearate is mixed as a lubricant additive together with the metal powder. The proportion of the lubricants varies from 0.5% to 5.0% by weight.

In the compacting phase in the press, the lubricants improve flow and compressibility characteristics; the binders have the opposite effect. The different amount of the two additives influences the porosity and final properties of the material. Zinc stearate has an advantage over other lubricants as it provides zinc for the alloy which is beneficial in certain processes.

Finally, the additives are volatilized from the part “in green” in the sintering oven after compacting in the press.

Plastics and Colour Additives

Like other stearates, it has a wide number of applications in the plastics industry::

It is used as a lubricant and stabilizer in the production of PVC.
As a pigment dispersant in Masterbatch.
Due to its properties of transparency it is used in impact glass applications, such as polystyrene for glass and other clear polymers.
As a metal releasing agent in polyurethane.

Lubricant in Extruders

To improve productivity in production using extrusion and lamination of plastics and metals, calcium stearate is added. It acts as an additive and solid lubricant adding between 0.3 -1.0% of calcium stearate to the mixture in the feed hopper. This remains stable at high temperatures and improves the following points in manufacturing:

Product homogeneity
Hot spots
Energy consumption
Saving of raw materials

Adplast integrates in the respective range of Stabilizers and Lubricants for PVC a line of Zinc Stearates with specific technical characteristics.

Plastics and Colour Additives