Over the last two decades, “polysiloxane” technology has facilitated a shift from three-coat to two-coat systems, reducing labor costs and downtime while improving weathering performance.

The goal with new high performance polymer technology is to meet the demand for low- and zero- VOCs products without diminishing the performance of the higher VOCs products that were in demand in the past.

For paint and coatings manufacturing companies Biro Technologies formulates and manufactures polymers and resins to meet new performance standards that replace harmful VOCs containing formulas. Our products have been low- to- zero VOCs or less than 10 grams per liter.

Polysiloxane’ Coatings Technology includes organic resin, methoxy-functional silicone resin and amino-functional silane/siloxane. The silane/siloxane acts as a bridge between the two resins; the amine group reacts with the functional group on the organic, and the alkoxy groups co-hydrolyze and condense with the silicone.

The chemical combination of epoxy and siloxane results in polymers with higher performance characteristics than can be achieved by the physical combination of all polymers. The chemical combination provides the basis for the joined polymeric strength, weathering durability, high temperature properties, and radiation resistance, gloss and color retention and corrosion protective properties of the polymers, whilst overcoming the brittleness of inorganic structures.

Epoxy-Siloxane coatings high cross linking density exhibit strong anti-corrosive characteristics. Due to the hydrophobic nature of the Epoxy-Siloxane coatings display anti-fouling, anti-graffiti and anti-icing properties.

Epoxy-Siloxane technology, virtually zero VOC system.

The typical properties of the Epoxy Siloxane coatings are:

Volume solids:                                                  100%

VOC (EPA method 24):                                  0 gram/l

Components:                                                   2

Curing mechanism:                                         chemical reaction, co-hydrolyze and condense

Mixing ratio by volume:                                                see stoichiometric ratio

Application methods:                                    airless and conventional spray, roller and brush

Thinning:                                                            alcohol, aromatics and esters.

Dry film thickness per coat:                        50-100 microns

Theoretical coverage (50-125 µm):           7.1 -18 m2 /l

Potlife (20°C)                                                     4 to 8 hours

Drying times (20°C)

To touch                                                              2 to 6 hours

Through                                                               3 to 8 hours

Recoat/topcoat time (20°C)

Minimum                                                            2 to 6 hours

Maximum                                                           none

Gloss:                                                                    90%

Flash points:                                                       A comp-252oC, 485oF

B comp-74oC, 165oF

The hardener used in Epoxy Siloxane hybrid coating is amino-functional silane or siloxane polymer.

The amine equivalent weight for these epoxy hardeners 110-135 g/eq

Improvements achieved with the Epoxy Siloxane polymer are:

  • 100% solids, zero to very low VOC inorganic hybrid coating
  • the process uses 100% reactive materials
  • low temperature curing (5oC)
  • reduced amine bloom and carbonization
  • a wide range of formulating latitude
  • improved substrate wetting
  • reduced effects on health, safety and environment
  • significant improved weathering
  • significant improved of thermal resistance (from 130oC to 190oC)
  • outstanding corrosion resistance
  • excellent resistance to nuclear radiation
  • excellent chemical resistance
  • excellent defense against graffiti
  • excellent surface spread of flame resistance
  • excellent for photocatalytic coatings

Application

  • Anti-Graffiti and Anti-Microbial coatings
  • Photocatalytic coatings
  • Industrial coatings
  • Anti-corrosive coatings
  • Marine / Antifouling coatings
  • Industrial flooring
  • Internal and external pipe coatings

Epoxy Siloxane polymer selection is dependent on the method of application, desired pot life, physical properties and curing conditions

Health, Safety and Environment

By its 100% solids content in combination with its ease of application without the use of thinners, a significant reduction of solvent emissions and waste is achieved. By its zero VOC level, the Epoxy Siloxane technology fully complies with the increasingly stringent environmental health and safety requirements without downgrading coating performance.

Epoxy Siloxane system represent a large improvement with respect to health, safety and environment compared to epoxy and polyurethane system.

Epoxy Siloxane system does not contain known health hazardous materials like isocyanates, which can cause respiratory sensitization.

Weathering

The polymeric structure contains repeating Si-O groups in the backbone of the Epoxy Siloxane hybrid polymer, providing the basis for its excellent weathering characteristics.

As a consequence, the Epoxy Siloxane coatings is hardly affected by sunlight, weathering or atmospheric oxidation in contrast to organic-based coatings that eventually degrade under these exposure conditions.

Epoxy Siloxane coatings retain their color and gloss far better than other topcoats in the protective coatings industry, such as polyurethanes, which show fading and loss of gloss in 3 to 5 years.

Outstanding corrosion resistance

A considerable improvement in durability has been achieved with Epoxy Siloxane coatings. This is demonstrated by the excellent performance of two coats Epoxy Siloxane based coatings as tested.

The two coat systems, consisting of 100-125 microns of Epoxy-Siloxane Zn primer followed by 50-100 microns of Epoxy Siloxane finish coat applied on SA 22 dry abrasive blast-cleaned steel, have been tested successfully for 5000 hours salt spray testing and 4000 hours cyclic test.

Nuclear radiation

Epoxy Siloxane coating is essentially unaffected by nuclear radiation and has an excellent rating for decontamination. The coating performed without any defects on irradiation to a cumulative dose of 4500 megarad as tested. Organic coating systems are showing considerable lower decontamination factors with typical values of 500 to 1000.

Defense against graffiti

Due to the hydrophobic nature of the Epoxy-Siloxane polymer offers an excellent defense against graffiti.

The use of the Epoxy Siloxane coating showed that the coating is easily cleaned of graffiti without leaving a shadow after cleaning.

Factors contributing to cost savings using Epoxy Siloxane polymer for coatings are:

Application cost saving factors:

– less number of coats

– reduced man-hours

– increased productivity – faster turn around times

– minimized scaffolding

– less disruption to other trades

– reduced coating weight

– reduced waste disposal cost

 Performance factors:

– improved color and gloss retention

– coating system life extended or maintained

 Health, Safety and Environmental aspects:

– reduced risk of industrial accidents

– reduction of waste

– reduced VOC emissions

– contains no isocyanates or lead chromates

Conclusion

The success of Epoxy Siloxane technology is a result of its unique characteristics achieved by chemical modification of the inorganic Siloxane backbone with functional organic epoxy groups.

This new technology provides the protective coating industry with greatly improved coating performance characteristics based on Epoxy Siloxane polymer system.