HG/T 4755-2014 Polysiloxane Coatings is the Chinese chemical industry standard that defines the technical requirements and performance criteria for polysiloxane coating systems. The standard specifies key performance indicators, including but not limited to:
· Non-volatile content (solids) >75%
· Si–O–Si (siloxane bond) content in the total coating >15%
· Xenon arc weathering resistance ≥3,000 hours
· Neutral salt spray resistance ≥3,000 hours
· Damp heat resistance ≥3,000 hours
Driven by increasingly stringent environmental regulations and the growing demand for long-term asset protection, the revision of this standard has been officially initiated since 2025.
As one of the drafting organizations for the new edition, Quark New Material has actively participated in the development of the technical specifications. We are committed to advancing polysiloxane technologies toward a safer, greener, healthier, lower-carbon future while delivering longer-lasting protective coating solutions.
1. Higher Solids Content: Supporting Long-Term Protection and Sustainable Coatings
The revised HG/T 4755 standard introduces two performance grades for non-volatile content (solids):
· Standard Grade: ≥75%
· Premium Grade: ≥90%
Quark's self-developed polysiloxane resins feature nearly 100% solids while maintaining exceptionally low viscosity, making them ideal for high-solids and solvent-free coating formulations.
Higher solids content significantly reduces the use of organic solvents, improves raw material utilization, enables higher dry film build in a single application, and enhances the overall coating performance. These advantages make polysiloxane technology an ideal platform for next-generation environmentally friendly, high-performance coating systems.
2. Significantly Enhanced Weatherability: Raising the Xenon Arc Requirement from 3,000 to 4,000 Hours
The current HG/T 4755 standard requires polysiloxane coatings to withstand at least 3,000 hours of xenon arc accelerated weathering without blistering, cracking, or delamination.
The revised standard further raises the benchmark:
· Standard Grade: ≥3,000 hours
· Premium Grade: ≥4,000 hours
Quark's polysiloxane resin has demonstrated weatherability exceeding 6,000 hours under rigorous xenon arc testing, while maintaining excellent gloss retention and minimal color change.
Compared with conventional polyurethane and acrylic coating systems, Quark polysiloxane technology delivers substantially superior durability. Compared with fluoropolymer coatings, it also offers the advantages of lower VOC emissions, improved safety, and enhanced environmental sustainability.
These properties make it particularly suitable for demanding corrosion protection applications such as:
Wind turbine towers|Steel Structure Bridges|Offshore steel structures|Outdoor industrial equipment
The outstanding weather resistance extends coating service life and significantly reduces maintenance frequency and life-cycle costs.
3. A Safer and More Sustainable Alternative to Conventional Polyurethane and Fluoropolymer Systems
Conentional polyurethane and fluoropolymer coatings typically contain 350–650 g/L VOCs, making it difficult to formulate truly high-solids or solvent-free systems. In addition, these coatings often require isocyanate curing agents, which present recognized health hazards, including respiratory sensitization and occupational exposure risks.
Many conventional coating products are also classified as hazardous chemicals, resulting in higher compliance costs during storage, transportation, and application, while increasing operational safety risks.
Quark polysiloxane resins enable the formulation of solvent-free or high-solids, low-viscosity coating systems. These formulations are non-hazardous, feature VOC levels below 100 g/L, and provide outstanding environmental, occupational health, and safety benefits.
As global environmental regulations continue to tighten, polysiloxane technology offers a future-oriented solution that combines regulatory compliance with long-term corrosion protection throughout the entire service life of coated assets.
