Zinc Borate 3.5 Hydrate (ZnO•3B₂O₃•3.5H₂O)

Welcome to buy high quality Zinc Borate 3.5 Hydrate (ZnO·3B₂O₃·3.5H₂O) from Taixing factory, this product is a white crystalline powder that is normally insoluble in water and most organic solvents, and has stable chemical properties. This product is not simply a "zinc borate" commodity, but a standardized engineering material with strict chemical stoichiometry and controllable crystal water content. By achieving a stepped dehydration and heat absorption in the temperature range of 290-320 ℃, it can efficiently suppress combustion reactions and avoid material foaming and cracking caused by rapid dehydration.

Core strengths

1. Precise "cascading" thermal management

The crystalline water in ZnO·3B₂O₃·3.5H₂O is its functional core. When heated, these water molecules are not released simultaneously, but are removed in stages within a relatively narrow but controllable temperature range (starting at around 290 ° C). This process:

·Efficient heat absorption: Each gram of material can absorb up to 500J or more of heat, rapidly reducing the surface and front temperature of the material.

·Dilution gas phase: The released water vapor effectively dilutes the concentration of combustible gases and oxygen in the flame area.

·Synchronous triggering: Its dehydration temperature window perfectly connects with the initial decomposition temperature of many common polymers (such as PVC and polyolefin) and the later thermal effect of aluminum hydroxide (ATH, dehydration peak~200-220 ° C), forming a continuous "endothermic protection chain".

2. Coalification of condensed phase and construction of ceramic barrier

After dehydration, the activated ZnO-B ₂ O3 composite oxide plays a crucial role in the condensed phase:

·Catalytic carbonization: catalyzing the dehydrogenation and cross-linking of polymer matrix, promoting the formation of stable and continuous high-quality expanded carbon layer.

·Glass state sealing: The generated borate melt (melting point~500 ° C) flows and spreads on the surface and pores of the carbon layer, forming a hard, dense, and self-healing glass ceramic composite barrier, effectively isolating heat and oxygen from transferring inward, and significantly suppressing the generation and escape of smoke particles.

3. Gas phase radical quenching

The released boric acid species (such as HBO ₂) enter the gas phase and efficiently capture key H · and OH · radicals in the combustion chain reaction, interrupting flame propagation.

Application field

1. PVC and chlorinated polymer system (core application)

·Function: Replace or partially replace antimony trioxide as an efficient flame retardant smoke suppressant synergist. Reacting with HCl to generate metal chlorides, enhancing gas-phase flame retardancy, while promoting char formation, achieving low smoke and low toxicity.

·Typical formula recommendation: Adding 5-15 phr to soft PVC wire and cable materials can significantly reduce smoke density, improve oxygen index, and enhance anti drip properties.

2. Halogen free synergistic system with aluminum hydroxide/magnesium hydroxide

·Function: Achieve three-dimensional efficiency enhancement of "time temperature space".

·Time: Its dehydration peak extends the overall endothermic protection time after ATH/MDH.

·Temperature: Its dehydration and heat absorption cover a higher temperature range, protecting the matrix polymer.

·Space: The glassy melt formed by it wraps around and fixes the oxide residue after ATH/MDH dehydration, creating a stronger barrier.

·Typical formula recommendation: Adding 5-10 phr to ATH/MDH system in EVA/PE halogen-free cable material can improve the processing flowability and mechanical properties of the system while maintaining the same flame retardant level, and significantly reduce smoke volume.

3. Elasticity and Engineering Plastics

·Function: As an effective smoke suppressant and anti drip agent in rubber, PA, PBT. Its heat release characteristics help the material pass more stringent combustion tests (such as UL 94 V-0).

4. Fireproof coatings and sealing materials

·Function: In the expansion type fireproof coating, it is not only an acid source, but also a gas source and a carbon layer enhancer, which helps to form a stronger and more erosion resistant expansion carbon layer.

Taixing provides high-quality Zinc Borate 3.5 Hydrate and ZnO•3B₂O₃•3.5H₂O flame retardant solutions for global customers. We look forward to establishing a long-term and stable cooperative relationship with you.