Hollow Glass Beads For Coastings Paint Matting Agent
Hollow glass beads can be used as a matting agent in coatings lies in their micron-sized spherical hollow structure, which creates microscopic surface roughness after film formation, inducing diffuse reflection of light. They also possess the unique advantages of low oil absorption and minimal thickening.
Matting Mechanism Surface Micro-Roughening:
The microsphere particle size (typically 5-50μm for optimal matting) is larger than resin molecules. During drying and curing, some particles protrude from the paint film surface, disrupting the specular smoothness and causing diffuse reflection of incident light instead of specular reflection, thus reducing gloss.
Refractive Index Matching and Scattering: The refractive index of glass (approximately 1.5) is close to that of common resins (1.4-1.6). Although glass has high transparency, matting is achieved through geometric optical scattering caused by physical protrusions, rather than internal scattering due to refractive index differences.
Hollow glass beads microsphere, whose main chemical composition is soda lime borosilicate glass, appear as hollow, transparent spheres under a microscope. They possess a variety of properties including low density, high strength, low thermal conductivity, electrical insulation, high temperature resistance, and acid and alkali resistance. They also exhibit good flowability and chemical stability, making them a multifunctional, cutting-edge new material across various fields.
Product Characteristics:
Appearance: White, free-flowing powder
Microscopic appearance: Transparent, hollow, perfectly spherical
True density: 0.12~1.60 g/cm³
Bulk density: 0.10~0.62 g/cm³
Particle size: 2~130 μm
Thermal conductivity: 0.038~0.085 W/m·K
Maximum compressive strength: 30000 psi pH: 8~9.5
Production process of hollow glass beads microsphere:
Solid-state fusion method the solid melting method, also known as the solid-phase method or glass powder method, uses silica (quartz sand) as the raw material, and adds auxiliary materials such as sodium carbonate, calcium carbonate and borate. The glass is melted at high temperature in a furnace, then ground into powder and hollowed into spheres at high temperature.
The thermal conductivity of hollow glass microspheres in different materials is as follows:
Material Thermal Conductivity (W/m*K)
Cork：0.13
Fiberglass：0.40
Acrylic Glass：0.18
Nylon 66：0.30
Polypropylene：0.22
25%GF Polypropylene：0.25
Asbestos：0.25
Hollow Glass Microspheres：0.038-0.085
Micrograph:
The main benefits of hollow glass beads microsphere:
Improved thermal insulation and sound insulation performance
The thermal conductivity of hollow glass microspheres is only one-tenth that of the matrix material.
Reduced resin usage, lower VOCs
True density: 0.12~0.70 g/cm3
Bulk density: 0.10~0.40 g/cm3
Improved material processing performance, reduced shrinkage and warping, and maintained dimensional stability
Hollow glass microspheres have the smallest surface area to volume ratio, an aspect ratio of 1:1, and are isotropic, overcoming the defect of inconsistent shrinkage in different parts caused by orientation.
The hollow glass microbeads endow the material with a series of outstanding properties.
Reduce the proportion
Reduce the amount of resin used
Improve dielectric properties
Reduce contraction and warping
Improve the rigidity of the material
Prevent material from cracking
Improve the insulation and heat preservation performance
Improve the sound insulation and noise reduction performance
