Flame Retardants

Product Overview

General Description

Although PVC is a halogenated polymer (approximately 57% chlorine by weight) that by itself tends to self-extinguish by releasing HCl as a radical scavenger, some additives included in its formulation have the opposite effect. An example of additives that affect this property are plasticizers, as they reduce the limiting oxygen index ( LOI). It is true that there are other additives designed to minimize this effect, and our technicians can certainly advise you on this.

Flame retardants for PVC are used to counteract this effect and are typically employed in flexible applications. They are used in the manufacture of electrical cables and other electrical applications to increase escape time in the event of a fire.

These flame retardants for PVC help formulators meet UL 94 flammability standards (categories V-0, V-1, V-2 for vertical testing and HB for horizontal testing) and the flame tests of the Mexican standard NMX-J-010-ANCE (equivalent to ANSI/UL 83) for electrical cable. Their dosage varies according to the required specifications.

Antimony Trioxide

Antimony trioxide is a highly effective flame retardant. Additionally, when used in conjunction with brominated, chlorinated, or borate compounds, it creates a synergistic effect, reducing the generation of combustion gases. When used for PVC cable insulation and jacketing, it can achieve the most demanding properties for low-voltage cables (up to 600 V) type THWN-2 according to NMX-J-010-ANCE, equivalent to the ANSI/UL 83 standard. In combination with commercially available borate compounds (such as zinc borate), it can reduce smoke and acid gas emissions and helps achieve a better LOI (Limiting Oxygen Index). It is a good additive for complying with UL 94.

Chlorinated Paraffin

Chlorinated paraffin functions as a secondary plasticizer and provides other important characteristics such as stain resistance, migration resistance, and low-temperature flexibility. It is also compatible with all plasticizers used in PVC formulations. Significant cost savings are achieved by using chlorinated paraffin as a partial substitute for the primary plasticizer, without compromising quality.This material is also used as a flame retardant in the manufacture of plastics, paints and adhesives; in combination with Antimony Trioxide it improves the flame-retardant properties of the compound and consequently reduces production costs.