Applications




COLLOIDAL SILICA

Applications :



Colloidal Silica is water based high temperature binder containing no toxic organic solvent or polymers. Colloidal silica particles have chemically active surfaces that bond readily to many types of granular and fibrous materials, especially those used for refractory or ceramic applications. The high surface area and reactivity of the silica particles make them very effective inorganic binders for high temperature applications.

Precision Investment Casting :
Colloidal silica has high bonding power with a variety of refractory grains such as :
  • Zircon
  • Fused silica
  • Alumina

The resulting shells are strong, with low coefficients of thermal expansion and excellent surface reproduction. Colloidal silica contains no volatile organic compounds (VOC).




Inorganic Fibrous Shapes

Colloidal silica is used as binder for vacuum forming refractory fibrous shapes such as :

  • Insulation board
  • Ceramic fireplace logs

Where high temperature stability is required.




Advantages of using Colloidal Silica with ceramic fibres composites as binder are:

  • Resistance to thermal shock.
  • Practically no thermal expansion.
  • Resistance to mechanical shock and vibration.
  • Flexibility in control of product properties.
  • Usefulness at temperatures up to 1650°C (3000°F) with certain fibbers.



Refectory Cements
 

Formulation of Colloidal silica with milled alumina silicate fibres help to make fibrous cements for trowel application or for use in steel mills and other refractory cements and gunning uses. Modified cements or gunning mixture exhibit following properties :


  • Minimum shrinkage
  • High strength at temperatures up to 1260°C.



Products :

  • ZCS- 30%.(with/without Anti freeze)
  • Ammonia Stabilized.
    Soda Stabilized.
  • ZCS-40%. (with/without Anti freeze)
  • ZCS-20% ACIDIC.
  • ZCS-30% ACIDIC.
  • ZCS-30% NEUTRAL.

Along with new developments in concrete technology and an increasing environmental awareness, the construction industry is looking for alternative ways to blend improved concrete performance with both economic and environmental concerns.


The use of colloidal silica in concrete applications can help prevent segregation and bleed in self-compacting concrete.  It can also improve the utilization of cement due to its strength providing properties.


In applications for well cementing, when colloidal silica is mixed with cement, the slurry becomes extremely stable and free water is eliminated.  Due to its low specific gravity colloidal silica works extremely well in lightweight slurries.  In the low temperatures of deep and ultra deep waters, colloidal silica provides substantial enhancement of early compressive strength, thereby shortening the setting time of the cement slurry.  Since wait of cement time is reduced, drilling can resume sooner.



Products:

  • ZCS- 500
 

Colloidal silica can improve the function of some water borne, clear wood coatings.  Through the formation of a silica skeleton, mechanical properties can be enhanced to get a harder, more durable coating while improving the anti-blocking properties. 


Not only the coatings have these improved physical properties, it looks better due to enhanced wetting properties of the coating that improve adhesion as well as penetration.  This penetration helps in giving the waterborne coating that "solvent borne look".


The slip resistance of self-polishing floor waxes can be improved by proper formulation with colloidal silica.


The colloidal silica may be added directly to :

  • Water emulsion floor waxes
  • Aqueous acrylic dispersions
  • Styrene
  • Ester
  • Other polymers
  • Aqueous solutions of resins used in floor polishes

Alternately, colloidal silica formulations may be applied to the surface of waxed dance, gymnasium, and theatre floors to make them less slippery. Floor polishes that ensure safe footing without sacrificing glossiness can be created by adding approximately 15–25% silica solids to the polish. The tackiness of the surface finish under high humidity conditions is reduced, and film toughness is increased.


Cushioning made from polyurethane or rubber foams can be made more compression resistant through the addition of colloidal silica. The addition of 3% silica solids to the formulation before foaming will increase compression resistance by 10-20% at a lower raw material cost. The area of deco coatings brings some new, exciting opportunities for enhancing the application with colloidal silica.

 

One functional benefit that colloidal silica can provide is the area of anti-soiling.  By adjusting the hydrophobic/hydrophilic balance of the coating, the coating will shed dirt - naturally.  The result is a coating that looks clean and fresh reducing the need for manual cleaning or recoating. Another functional benefit is by increasing the strength of the coating.  Colloidal silica particles reinforce the coating system and make a tougher, more durable coating.  The result is a coating that can resist bumps and knocks that would mar other coating systems.


Colloidal silica is used alone or in formulations to coat mineral surfaces to improve the corrosion resistance and durability. Colloidal silica is used in inorganic paint like silicate paint and can easily be formulated with potassium silicate as the main binder.  In silicate paints, colloidal silica reduces the alkalinity and water absorption and improves the anti-soiling properties.  It also helps reduce internal stress by reducing the shrinkage in the coating.  Surfaces that can benefit from these coatings include all forms of natural stone and masonry.  A coating with colloidal silica will give years of protection and reduce the need for maintenance and other restoration work.




Benefits Using Colloidal Silica :

  • Colloidal Silica increases hardness.
  • Increases abrasive resistance and friction.
  • Increased adhesion.
  • Reduces drying time.
  • Improves sanding properties.



Products :

  • ZCS-30%SM
  • ZCS-40%SM
 

Colloidal silica has been found to improve the performance of Cr III to almost Cr IV standards.  Also, colloidal silica has an extra benefit in the stabilization of electroplating baths by providing ionic stabilization without adversely effecting bath performance. For zinc rich coatings used to protect steel in construction facilities, colloidal silica can be used as a binder.  This results in a hard, durable coating that protects steel and prevents oxidation in construction environments.




Product :

  • ZCS-15% AS.
  • ZSC-30% AS.
 

Colloidal silica particles, modified silica dispersions, have a high number of hydroxyl surface groups that can interact with other chemical groups on substrates.
Colloidal silica is one of the few materials that can enhance glass adhesion in a resin based coating.  Colloidal silica also will reduce shrinkage of the polymer matrix in lacquers during drying.  In adhesives, they can be used to assist in the stabilization of waterborne emulsions. The addition of colloidal silica to latexes used as adhesives increases bonding strength to smooth surfaces such as paper, fabric, leather, or glass.
Colloidal silica particles align themselves with latex particles. When the latex coalesces during dry down, the silica becomes an integral part of the matrix.
The addition of 5-20% silica (based on polymer solids) improves adhesion, durability, and chip and scrub-resistance.



Product :

  • ZCS-30% SM.
  • ZCS-40% SM
 

Colloidal silica is used for the dispersion of many inorganic pigments and fillers.  The charged colloidal silica particles surround the filler or pigment particles and act as a spacer to keep the particles separated.  This greatly increases the light scattering efficiency.


The benefits are:

  • Good dispersing power and pigment wetting
  • Surfactant free pigment paste
  • Enhanced opacity
  • Reduced foam formation (in paste and coating)
  • Improved chemical resistance in coatings
  • Possibilities for improving process efficiency
  • Good pigment paste stability and easier to re-disperse paste if settled
  • Easy to use and not shear sensitive



Product :

  • ZCS-500 SM

The plastic film coating market mainly consists of coatings for polypropylene,     polyester or other polyolefin for use in wrapping of food, tobacco, confectionery, and for tape production.
As a coating, colloidal silica is widely used in latex emulsions for these films to impart barrier effects and friction to the surface as well as improving printability.  When integrated into the polymer, colloidal silica can yield the benefits it can yield as a coating, but also it can improve the binding of the plastic.




Product :

  1. ZCS-30% SM
  2. ZCS- 40% SM

Colloidal Silica is used in formulations in the textile industry. Colloidal Silica is compatible with other organic polymer. Colloidal Silica protects the weave structure, improve seam slippage, dry hand, and control fabric sheen in textiles. Colloidal silica gives special finishing effects to blends and to fabrics made of cotton, wool, synthetic fibres and filaments. Textile finishers achieve outstanding results in dyeing and finishing using Colloidal Silica.


Basically Colloidal Silica used for preparation of coatings on highly flexible materials such as textiles or paper. Nevertheless the Colloidal Silica compositions as well as the application procedures have to be adapted with respect to the particular demands of the textile substrates as required by the textile industry. In general every compound that is miscible with the precursors or the sols and that is able to form a covalent bond to the metal oxides and that does not increase the gelation intolerably can be introduced into the sol-gel derived networks. Even larger and more complex organic compounds such as dyes or active agents can be bonded covalently using Colloidal Silica.

 

The modification with Colloidal Silica can also be carried out with additives that are homogeneously incorporated and immobilized into the metal oxide matrix without forming covalent bonds. These additives are usually larger molecules such as polymers, pigments, dyestuffs, active substances or bio molecules. The incorporation can occur by adding the additives either before, or after hydrolysis of the precursors both routes will lead to comparable composite structures and immobilization behaviour since it is assumed that encapsulation actually occurs during the formation of the network. The immobilization of additives within the inorganic matrix is very efficient. In inorganic-organic hybrid materials, the organic component usually accounts for flexibility of the composites whereas the inorganic component is responsible for hardness and mechanical impact resistance.  




Product:

  1. ZCS-30%.
  2. ZCS-20% ACIDIC.
  3. ZCS-30% ACIDIC.
  4. ZCS-30% NEUTRAL.




POTASSIUM SILICATE

Soluble silicates are manufactured by fusing high purity quartz sand (SiO2) with sodium or potassium carbonate (Na2CO3 or K2CO3) in an open hearth furnace at 1100 – 1200°C. The resulting glass is then dissolved using high pressure steam to form liquid silicate or “waterglass” which is clear and slightly viscous. The key parameter that determines the properties of soluble silicate solutions is the weight ratio of SiO2/Na2O or SiO2/K20.

High-temperature binding :
The violet flame colour of potassium versus the blinding, intense yellow colour of sodium makes ZPS ideal for high-temperature welding with carbon arc electrodes. The soft violet hue is easier to see through when welding.



Silicate based paints :
Coatings made with ZPS potassium silicates do not develop a white carbonate film – or efflorescence – on exposure to the atmosphere, making them a preferred choice for decorative coatings, paints, and ceramic binders. ZPS potassium silicates are more soluble. They are also more compatible with many other ingredients and, consequently, ideal for use in the formulation of liquid, heavy-duty detergents, and built liquid and paste soaps, which include many other ingredients in their formulations.



Non-tacky :
ZPS potassium silicates’ non-tacky properties make them a value-added ingredient for certain mortars. These properties help prevent mortar from sticking to a mason’s trowel. This allows for greater bricklaying efficiency and reduced bricklaying labour costs.



Refractory :

Because ZPS potassium silicates soften and flow at a higher temperature than sodium silicates, they work well in various high-temperature binders such as refractory mortars and specialty cements.




PRODUCT
  • ZPS-30



LITHIUM SILICATE

Basics of Lithium Silicate :

Lithium is alkali metal found in Group 1A of periodic table and atomic number of 3.Lithium is very reactive metal because of its tendency to expel its outer electron. It has valence of +1.Lithium is the lightest dense metal, with a density about half that of water (0.53 g/cubic centimetre).


How does lithium silicate work?

Reaction mechanism of lithium silicate with cement :

Lithium silicate react with Calcium Hydroxide (also referred to Portlandite) a by product of cement hydration to produce calcium silica hydrate(C-S-H) the same binder that results from adding water to cement and gives concrete much of its strength and hardness. In the hydration process, calcium hydroxide dissolved in water moves to the surface region of slab where lithium silicate reacts. The newly   C-S-H is deposited primarily in the pores and canals on the surface of a slab. When calcium hydroxide comes on the surface of fresh concrete it reacts with atmospheric carbon dioxide producing calcium carbonate.


The reaction of lithium silicate with calcium hydroxide in concrete produces lithium hydroxide and insoluble calcium silicate to create a breathable protective barrier. Function of lithium part of silicate’s function only to stabilize and solubilise the silicate so that it can remain in the solution until it penetrate the concrete and then reacts with abundant calcium hydroxide found in concrete. Lithium silicate is alkaline raising pH of the surface of concrete and reducing possibility of ASR (alkali silica reaction).Lithium silicate alters the ASR product resulting in non expansive product.

 

Lithium in lithium silicate reduces repulsive forces in colloidal ASR gel particles. Higher reactivity of lithium also means you don’t have to scrub it into concrete to encourage the reaction. Lithium ion on a weight basis can stabilize more silicate ions. Lithium silicate has low viscosity so it can penetrate in to concrete more efficiently. When applied in correct amount it dries to dust.




Advantages Of Using Lithium Silicate As Concrete Hardener :

  • Lithium’s reaction in concrete is non-expansive. As a result it won’t contribute to crazing or map cracking.
  • Lithium reacts more evenly throughout surface zone.
  • Lithium ion is smaller ion than sodium and potassium so it penetrates better.
  • After treatment lithium ion can not be leached out by water.
  • The treatment is penetrating and is a permanent protection.
  • Can be applied on existing or new cured concrete.
  • Improves strength for old, deteriorating and weak concrete.
  • Transformation of porous concrete in to dense surface that inhibits water, oil and other contamination from penetrating.
  • Provides maximum hardening to improve abrasion resistance and reducing dusting.
  • Treated surface is protected from damages caused by water and chemical attack.
  • Treated surface will not peel or flake off.
  • Non expansive gel will not absorb water or cause sweating.
  • Lithium content will combat ASR.
  • Lithium silicate is water base, non flammable, non toxic, extremely low odour and contains no solvent.

 

This combination was developed to combat Alkali Silica Reaction (ASR). Where Sodium or Potassium Silicates are frequently exposed to water they can re-solubilise, raising PH levels and eventually causing the concrete to weaken, crack, and generally disintegrate. The Lithium Silicates are less susceptible to ASR because the lithium stabilizes the silicate more efficiently. This results in improved performance while maintaining lower PH levels, resulting in longer life for the concrete. Lithium Silicate’s unique reactive chemistry forms an insoluble permanent bond with concrete surface rapidly curing (dry to touch in 30 -60 minutes) in to micro protective surface film.

 

Lithium Silicate’s adhesion properties will not flake or peel. The advanced Lithium Silicate will not absorb water or effect alkalinity once cured and is suitable for interior use also. Lithium Silicate‘s lower viscosity than conventional treatment provide superior penetration within the capillary channels providing a more consistent and uniform cure.


Once it has penetrated into porous concrete surface. Lithium Silicate undergoes a series of chemical reaction resulting in total cross-linking, reinforcing and sealing the concrete surface by forming a durable chemical bond with the surface and therefore provides a long-term protection (many times longer than conventional concrete sealers).


This microfilm-forming treatment offers greater stain and abrasion resistance, and greater strength and durability than traditional coatings, sealers and densifiers. In a class of its own, Lithium Silicate provides long-term protection and guards surfaces against severe and aggressive industrial environments. With good maintenance, treated surfaces maintain sheen even against heavy pedestrian and traffic wear. Floors last longer and cost less to maintain. Lithium Silicate can be mixed with organic polymers to achieve lotus effect.




Advantages of using Lithium Silicate :

  • Extremely durable stain resistant micro film forming surface treatment that will not Peel or flake and both chemically and mechanically react with the substrate.
  • Easy maintenance, easy re-coating. Won’t build up or yellow.
  • Resists strong cleaning compounds, alkalis solvents, oils and many acids.
  • Easy one-coat application.
  • Can be applied using simple methods, such as spray, roller, or brush.
  • Permanent and durable surface resists marks, improves traction, and helps prevent Water borne containments for staining.
  • Makes concrete easier to clean, creating an environment that is less susceptible to the proliferation of harmful bacteria
  • Extends the life expectancy, and integrity of concrete and masonry.
  • Increases abrasion resistance and surface hardness.
  • Does not require rinsing or flushing with water following product application — eliminates the costly disposal of hazardous (alkaline) rinse water.
  • Hardens and increases the abrasion, impact and wear resistance of concrete floors where high volumes of pedestrian and/or forklift traffic are expected.
  • Provides permanent protection to the depth of penetration.
  • Reduces the porosity of concrete surfaces to improve the chemical and stain resistance to most organic acids, alkalis, salts, foods, fats, oils, greases.
  • Densifies, strengthens, seals and dustproof soft concrete floors.
  • Improves the adhesion of subsequently applied line stripes, paints and coatings to soft or weak concrete surfaces.
  • Overall performance and life far surpasses that of conventional membrane forming acrylic cure and seal type products.
  • Allows the floor to breath, preventing hydrostatic pressure related adhesion failure.
  • Complies with USDA requirements for incidental food contact.



Potential Use :
  • Used to seal, harden and densify all new and existing interior concrete floor surfaces.
  • Ideal For use in warehouse, retail store, restaurants, indoor malls, office complex, food processing plants, dairies, breweries, food lockers, slaughtering plants, animal pens and bottling plants.
  • Excellent for use to protect, seal and improve the appearance of concrete countertops. Increases abrasion resistance and surface hardness.
  • Ideal for use in Lithium ion Battery.
  • To create lotus effect on the wall.
Comparison with other Silicates (SODIUM/POTASSIUM) :
  • Other silicates on drying exhibit efflorescence. They are highest with sodium silicate, lower with potassium silicate, lowest with lithium silicates.
  • Application of lithium silicate is easier and proceeds fast.
  • Leaves no residue to clean up.
  • Environmental Protection Agency (EPA) rates silicate residues as hazardous material because pH levels are high (10+).
  • When residue deposits on surface of slab forms white crystal which is difficult to remove.
  • Other silicates form expansive alkali silica gel to seal the surface. That is why evenly, properly finished and cured silicates develops map cracks after application of sodium and potassium silicates.

Products
  • ZLS-22



SODIUM SILICATE

Soluble silicates are manufactured by fusing high purity quartz sand (SiO2) with sodium carbonate (Na2CO3 or K2CO3) in an open hearth furnace at 1100 – 1200°C. The resulting glass is then dissolved using high pressure steam to form liquid silicate or “waterglass” which is clear and slightly viscous. The key parameter that determines the properties of soluble silicate solutions is the weight ratio of SiO2/Na2O. For example, a “3.2” ratio sodium silicate has 3.2 kg of SiO2 for every 1kg of Na2O. The typical range of commercially available ratios is 1.6 to 3.2.

 

At the molecular level, the fundamental building block of silicate species is the silica tetrahedron consisting of the silicon atom at the centre of an oxygen-cornered pyramid. Each oxygen atom may be associated with a hydrogen atom an alkali metal (Na, K, Li), or it may be linked to another silica tetrahedron. The silica can link to form chains, cyclic and larger polymeric structures. The species typically carry an overall negative charge having the mono valent alkali atoms in loose association.


Monomer Linear Trimer Cyclic Trimer
     


Monomer Silica Tetrahedron, Linear and Planar Cyclic Silica Species :

Soluble silicates then are inorganic, polymeric, alkaline materials. They are also moderately strong buffers and can be involved in four basic types of chemical reactions, each of which can play a role in binder applications. The chemical reactions are:

  • Gelation .
  • Metal Ion Reactions / Precipitation.
  • Hydration / Dehydration.
  • Surface Charge Modification.

Agglomerated materials require a binder in order to achieve acceptable strength. In general, binders can be divided into three groups :

  • matrix
  • film
  • chemical

4 Sodium silicate is unique in that it can serve in all three of these capacities. For example, as a matrix binder, sodium silicate would be used in conjunction with Portland cement or blended cement binders. Further discussion on film forming and chemical binding attributes follows.

Film forming binders are like glues and function by the evaporation of water or other solvent. Commercially available sodium silicates contain 45-65% water by weight. Loss of a small portion of this water, even under ambient conditions, will result in a strong, rigid, glassy film.

 

Rate of drying will depend on ratio, concentration, viscosity, film thickness as well as temperature and relative humidity. The silicate binder may be subject to dissolution depending on use conditions; however some moisture resistance can be obtained by simply drying the silicate more completely through the addition of heat.

Chemical binders function by reacting with the material being agglomerated or by formulating with multiple components that will react with each other. Sodium silicate has a long history of being used as a chemical binder.

 

The best example is the use of sodium silicate with a soluble source of calcium. The reaction of calcium salts with silicate forms calcium silicate hydrate.

 

Other traditional setting aids used with sodium silicate are shown in Table :

Traditional Setting Agents Category Example
Inorganic Salts : CaCl2, Ca(OH)2, Mg(OH)2, NaH2BO3, Na2CO3
Mineral Acids : H2SO4, HCl
Organic Acids : CO2, acetic acid, citric acid
Inorganic Oxides : ZnO, CaO, MgO
   

PRODUCT
  • ZSS-8
  • ZSS-11