Zinc borate.

The company's zinc borate is said to be an important additive to help achieve excellent flame resistance in rubber articles. It is a free-flowing powder that is said to disperse easily. Zinc borate can be added to any flame retardant system and will improve flame test results with minimal effect on compound properties, according to the company. Zinc borate will form a glassy char at high temperatures that prevents flame propagation. It also releases water of hydration similar to ATH. Zinc borate is a synergist with antimony oxide and halogenated flame-retardants, as well as ATH. The combined ingredients will have better flame resistance than the separate materials would have, according to the company. Zinc borate is said to help in compounding halogen-free, flame-resistant rubber that generates minimum acidic smoke. The company's zinc borate is said to work in concert with virtually all other flame retarders. The synergy with antimony oxide allows half as much antimony material to be used to obtain comparable results, according to the company. The HT variety will not release its water of hydration until well above 500[degrees]F, which allows high temperature processing.

Akrochem Circle 52 on card