Zinc Borate 7 Hydrate

Zinc Borate 7 Hydrate is a white loose crystalline powder. It has excellent compatibility with polymer materials such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and unsaturated polyester resin. Its notable feature is the abundance of approximately 7 crystalline water molecules, which are carefully constructed within the crystal framework to form an active thermal management system that can be activated at relatively low temperatures (starting at around 120-150 ° C). To buy this product with affordable prices, you can contact Taixing, a reliable manufacturer and supplier in China.

Core strengths

1. Wide range and multi-stage thermal buffering and dilution effects

The release of crystal water from Zinc Borate 7 Hydrate exhibits a wide and controllable temperature range, extending from approximately 120 ° C to over 300 ° C.

·Early intervention (120-180 ° C): Release the first batch of crystalline water, absorb a large amount of latent heat in advance during the critical stage when the material is heated but not yet ignited, significantly increase the material's heat capacity and ignition temperature, and effectively delay the occurrence of combustion.

·Continuous buffering (180-300 ° C): The continuously released water vapor forms a stable gas-phase cooling zone and fuel dilution zone at the forefront of material decomposition, suppressing the peak heat release rate.

·Strategic synergy: Its wide dehydration range can seamlessly overlap with the endothermic behavior of various flame retardants (such as ATH's~200 ° C dehydration peak), creating an extended, gapless "thermal protection umbrella".

2. Trigger early carbonization of condensed phase and pre formation of barrier

The release of water is not an isolated event. The surface of active zinc borate produced after removing crystal water can catalyze dehydration and crosslinking reactions of polymer matrices (especially oxygen-containing and chlorine containing polymers) at lower temperatures. This means that before the flame spreads fully, a preliminary, carbon rich protective layer has been pre built on the surface of the material, laying a solid foundation for the subsequent formation of a high-strength final carbon layer.

3. The essence of being an efficient smoke suppressant

The generation of a large amount of water vapor not only dilutes combustible gases, but also greatly promotes the water gas reaction (C+H ₂ O → CO+H ₂) of burning smoke particles (carbon black), converting them into combustible gases and further burning them, thereby significantly reducing the amount of solid-phase smoke generated from the source and achieving essential smoke suppression.

Accurate technical specifications: controllable release dynamics

We ensure that the moisture content and release curve between batches are highly consistent through precise control of the synthesis process, making it a predictable formulation component.

Application field

1. Soft PVC and chlorine containing elastomers (flagship applications)

·Challenge: Efficient flame retardant and smoke suppression are required, but the processing temperature is low (usually 140-180 ° C), which limits the effectiveness of traditional flame retardants.

·Solution: HydroShield ZB-7H is extremely stable at PVC processing temperatures and responds quickly in the early stages of a fire (>150 ° C). It can efficiently replace or significantly reduce the amount of antimony trioxide used, react with HCl to generate gas-phase flame retardants such as ZnCl ₂, and at the same time, its water vapor strongly suppresses smoke. It is a core additive for producing low smoke, antimony free (or low antimony) PVC cable materials, flooring, and conveyor belts.

·Suggested dosage: 5-15 phr.

2. Low processing temperature halogen-free flame retardant system

·Challenge: EVA foam materials, certain LDPE films, low-temperature curing coatings, etc., with low processing/curing temperatures, but need to meet flame retardant standards.

·Solution: Compound with ATH/MDH. The early dehydration behavior of Zinc Borate 7 Hydrate perfectly fills the thermal management gap before the ATH dehydration peak (~200 ° C), providing full protection for the system from processing temperature to combustion temperature, and synergistically improving smoke suppression and anti drip performance.

·Suggested dosage: 10-25% of the mass of the main flame retardant (ATH/MDH).

3. Expansion type fireproof coating and sealant

·Function: As a multifunctional component that integrates foaming agent (water vapor), carbonization catalyst, and acid source (boric acid). Its stepped water release characteristics contribute to the formation of a more uniform and stronger expanded carbon layer with foam pores.

·Advantages: Simplify the formula and improve the expansion response speed of the coating in the early stage of low-temperature fire.

Frequently Asked Questions

Q: What are the fundamental differences and selection logic of Zinc Borate 7 Hydrate compared to the common 3.5 hydrate?

A: The fundamental difference lies in the starting temperature and intensity of thermal energy management. 3.5 Hydrates are the "medium temperature main force", releasing energy at~300 ° C and suitable for matching the main decomposition peak of polymers. 7-hydrate is an "early response and sustained buffering unit" that starts working at lower temperatures, providing a more proactive and persistent thermal buffering. The selection logic depends on the "temperature attack line" that you need to defend against: if your material has already decomposed into a large amount of combustible gas before reaching 300 ° C, early intervention with 7-hydrate is required; If the challenge lies in intense combustion above 300 ° C, 3.5 hydrate may be more direct and efficient.

Q: With such a high content of crystal water, how can we avoid the formation of bubbles or surface defects in the product due to trace dehydration during processing?

A2: This is the core challenge of the application and also the technical barrier of our product. We use crystal structure strengthening and surface microencapsulation technology to make the escape kinetics of crystal water extremely slow at processing temperatures. As long as the processing temperature is below 120 ° C and the time is reasonable, dehydration can be ignored. For users whose processing temperature is near the critical point, we provide a "dehydration rate curve chart", where you can accurately find the safe upper limit of processing temperature based on your actual residence time. The key lies in process control, not absolute prohibition.

Q: Is this product suitable for applications that pursue high transparency?

A: Not applicable. Its relatively large particle size (designed for functionality) and high refractive index difference can severely scatter light and cause opacity. It is mainly aimed at engineering application fields that do not require high transparency, but have high requirements for flame retardant and smoke suppression efficiency and cost.

Q: Is Zinc Borate 7 Hydrate environmentally compliant?

A: Fully compliant. Its main components are zinc, boron, oxygen, and water, all of which do not contain substances of high concern (SVHC) in the EU REACH regulation. It is halogen-free and has no heavy metal hazards. Its solubility in water is extremely low, making it safe for the environment. Complete MSDS and environmental compliance statement can be provided.