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Glass Paste and Sealing Glass Binders

QPAC® polymers degrade completely and uniformly into environmentally benign products making them excellent for high-performance applications, including low-temperature glass paste applications and low-temperature sealing glass applications.

Fired thick film pastes made with QPAC® are nearly identical in appearance to fired samples of the corresponding neat glass, indicating little or no remnant material from the binder. These reduced levels of residual carbon enable improved performance in the final thick film material and device. Additionally, QPAC® products of decomposition, carbon dioxide and water vapor, will not contaminate furnaces over time. This enables increased furnace loading and reduced furnace maintenance, thereby lowering manufacturing costs.

QPAC®40 (polypropylene carbonate) and QPAC®25 (polyethylene carbonate) decompose at significantly lower temperatures than other conventional binders such as ethyl cellulose. Additionally, the residual carbon level is significantly lower. These properties are highly beneficial in low-temperature glass paste and glass sealing applications.

The QPAC® sacrificial binder is added to a paste composition comprising a solvent and at least one low-temperature glass frit. The sacrificial binder provides a route for preparing paste with excellent homogeneity, low debind and sintering temperature, low impurity levels, and customizable physical features.

QPAC® acts as a sealing glass binder in low-temperature sealing glass applications in which low-temperature glass is used to seal to other glass substrates as in the manufacturing of OLED and LED displays. QPAC® is also used to bind glass powder/frit when joining nanotubes and phosphors to glass substrates.

QPAC® also provides excellent viscosity properties to the paste formulation for deposition. These paste compositions for forming glass composites can be directly written by screen printing or deposited by miniaturized pen and subsequently processed into solid-state materials.

Key benefits:

  • Compatible with a variety of sealing glasses and metals
  • Viscosities and molecular weights can be custom-tailored for a specific solution or paste requirements
  • Both grades of QPAC® are naturally “tacky,” and degrees of plasticity can be adjusted as necessary
  • Decomposition is complete through three phases: solid, liquid, and vapor
  • Very low ash residue with the complete burn-out of carbon
  • Decomposes completely between 220°C – 350°C, which can be as much as 100°C below the decomposition temperatures of other binders
  • Decomposition occurs before glass melts, resulting in higher density and less residual binder/contaminants trapped in the structure
  • QPAC® glass pastes have excellent rheology properties and suspension stability

Applications include:

  • Manufacture of flat panel displays (OLED, LED)
  • Fiber Optics
  • Glass Preforms
  • Glass Powders
  • Sealing paste for vacuum sealed windows
  • Other technical glass applications

Binders for Glass Powder Overview