Kasil potassium silicates offer a range of chemical and physical properties designed for use by the electronics industry. These electronic grades are designed for use as setting agents and phosphor adhesives in the manufacture of color and monochrome cathode ray tubes (CRTs). They meet or exceed industry requirements for low iron, copper, and sodium content.

Characteristics:

Kasil electronic grade potassium silicates are solutions available in a range of solids contents, ratios, and densities to meet application requirements.

The chemical composition of potassium silicates is customarily expressed in terms of their SiO₂ : K₂O weight ratios. The electronic grade Kasil potassium silicates ratios range from 1.60 to 2.0. All are clear liquids with densities ranging from 10.15 to 11.2 pounds per gallon. 

The viscosity of Kasil solutions is affected by ratio, solids concentration and temperature. The lower the ratio, that is, the more alkaline at a given solids content, the lower the viscosity.

Increasing temperature or a adding small amount of deionized water will also cause significant drops in viscosity.

Compatibility and Purity:

The low levels of iron, copper, and sodium in the electronic grade Kasil products make them compatible with phosphor compounds used in CRT manufacturing. All electronic grades contain less than 30 ppm iron and 1 ppm copper. High purity raw materials as well as total segregation of the potassium silicate manufacturing step assures users of these benefits.

Applications:

Kasil potassium silicates are efficient, time-tested phosphor binders and setting agents for CRTs used in computer monitors, oscilloscopes, radar screens, and automatic teller monitors.

As a settling agent, the potassium silicate is added to the tube as a disperse slurry. The silicate helps settle the phosphor particles into a smooth, continuous layer. It is effective with a broad spectrum of phosphors. The absence of magnetic metals in Kasil potassium silicate helps ensure that no pin holding or clumping occurs on the inside surface of the screen.

As an adhesive, potassium silicate bonds the phosphor to the glass. The lower ratio silicates also help to etch the glass surface more readily. The higher ratio silicates, however, offer more silicate for binding. With all ratios, lacquer coating are recommended to seal the phosphor material after the silicate-phosphor bond has hardened.

 Typical Composition and Properties of Kasil Electronic Grade Potassium Silicates:

                   Mole Ratio           Weight                      Ratio                               Density

                   (SiO₂/K₂O)        (SiO₂/K₂O)        %K₂O        %SiO₂          lb/gal            g/cm³

Kasil 2130:    3.30                   2.15                   9.5             20.              10.6               1.27

Kasil 2135:    3.30                   2.15                  11.0           24.0             11.0                1.33

                 Copper            Iron                 pH               Characteristics

Kasil 2130:   <1               <30                  11.7           Very clear liquid

Kasil 2135:   <1               <30                  11.9        Very clear; high solids