CNSL and Cardphenol based Varnishes/Paintmedia (Technical Note: ST 14)

Introduction Silac Varnishes/Paint Media Comparative Film Properties Applications Typical Formulations Technical Service

1.0  Introduction

They are high quality phenolic varnishes with MTO as solvent giving high glossy, hard films that are resistant to water and chemicals. They are manufactured in a sophisticated plant with automatic controls using an integrated continuous uninterrupted process from the starting state of raw materials to the final finish product.

1.1 Types: The available types can be described as follows:

 

Silac V 10 Pure CNSL based Varnish Silac V 20 Styrenated Cardphenol based Varnish Silac V 30 Styrenated CNSL based Varnish Silac V 20D DCO modified Cardphenol based Varnish

1.2 Silac V20 D: It is a phenolic varnish in which phenolic component Cardphenol aldehyde is modified with conjugated oil such as DCO. The C₁₅H₂₇ group of Cardphenol methylol reacts with the residual OH groups in DCO leading to a complex molecular structure which imparts comparatively less yellowing properties and higher exterior durability in addition to better adhesion flexibility. It has lighter colour and is supplied as 45% solids balance being MTO.

1.3 Compatibility: They are compatible in all proportions with drying oils. Their compatibility with other resins like alkyds, epoxies etc., is very good.

1.4 Solubility: These Varnishes are supplied normally with 55% MTO as solvent. If required they can be further thinned with MTO, Xylene, Toluene or solvent Naptha etc. They can also be supplied with larger solvent contents for special applications.

1.5 Mode of Supply: They are supplied in 200 or 20 Ltr. packings.

1.6 Recommended Driers: The recommended driers for air-drying items are 1% Lead or 0.4% Zirconium, 0.1% Cobalt, and 0.2% Manganese as metals on solid contents.

2.0 Silac Varnishes/Paint Media

Driers, can be used as excellent film formers. However if still better film properties are desired they can be modified with drying alkyds, oils, or other resins such as epoxies or urethanes etc.

The following table gives typical properties of Silac products.

 

Type Composition Colour of Film Sp. Gravity Viscosity 45% solids Drying Time* Scratch Hardness Acid value max Resistance to Chemicals Surfacedry (at 30oC) Hard Dry Hard Dry (at 120oC) Silac V 10 CNSL Varnish Reddish Brown 0.9 ± .02 300 to 450 Sec. ½ hr. 3 hrs. 25 mts. 1000 gms. 5 Good Silac V 20 Styrenated Card Phenol Varnish Pale Yellow 0.9 ± .02 225 to 350 ½ hr. 2 hrs. 15 mts. 1200 gms. 5 Excellent Silac V 30 Styrenated CNSL Varnish Reddish Brown 0.9 ± .02 205 to 350 ½ hr. 2½ hrs. 20 mts. 1100 gms. 5 Excellent Silac V 20 D Cardphenol DCO Varnish Light Golden 0.4 ± .04 250 to 350 ½ hr. 3½ hrs. 30 mts. 900 gms 7 Good

3.0 Comparative Film Properties

The Film properties of these Varnishes are compared with those of pure long oil alkyd 66% varnish made into 30% Solids in MTO & after adding driers as above.

Film properties Silac V 10 Silac V 20 Silac V 20 D Long Oil Alkyd Colour Reddish Brown Pale Light Pale Colour less Surface dry in Air ½ Hr. ½ Hr. ½ Hr. 1½ Hr. Hard Dry in Air 3 Hrs. 2 Hrs. 3½ Hrs. 5 Hrs. Appearance Highly Glossy Highly Glossy Highly Glossy Glossy Scratch Hardness 110 1200 900 600 Adhesion Good Better Better Better Flexibility Good Good Better Better Resistance to water NE (100) NE (100) NE (100) SB (24) Sodium Carbonate 5% NE (100) NE (100) NE (100) SB (8) Sulphuric Acid 2% NE (100) NE (100) NE (70) SB (12) White Spirit NE (100) NE (100) NE (100) NE (100) Outdoor Durability Good Good Very Good Excellent

NE – No effect, SB – Slight Blushing, () Bracketed figures indicate number of hours.

4.0 Applications

The scope of applications is limited only by the ingenuity and experience of the formulating chemist. However the following can be regarded only as suggestions to illustrate the versatility of these Varnishes/Paintmedia.

Application Suggested Particularly preferred Redoxide Primer Silac V 10, V 20 D Silac V 10 Zinc Chrome Primers Silac V 10, V 20 D Silac V 30, V 20 D Silac V 20, V 30 Airdrying/Baking Enamels:     Non white/Dark coloured Silac V 30, V 10 Silac V 30 Non white/Light coloured Silac V 20, V 20 D Silac V 20 D, V 20 Anticorrosive paints Silac V 10, V 20 Silac V 20 Anti fouling paints Silac V 30 Silac V 30 Food can lacquers Silac V 20, V 20 D Silac V 20 Insulating varnishes Silac V 20, V 30, V 20 D Silac V 20 Wood Finishes Silac V 20 Silac V 20 Aluminium Media Silac V 20 D Silac V 20 D

5.0 Typical Formulations

They should be regarded as indicative of their possible applications.

5.1 Red Oxide Primer:

Red Oxide 16 parts by weight Talc or whiting 13 parts by weight China Clay 9 parts by weight Anti settling agent 0.3 parts by weight Anti skinning agent 0.01 parts by weight Zinc Octoate 0.2 parts by weight Silac V 10 25.0 parts by weight

5.2 Zinc Chrome Iron Oxide Primer:

 

Iron Oxide 18 parts by weight Talc or whiting 25 parts by weight Zinc Chrome 45 parts by weight Silac V 30/V 20 D 325 parts by weight Anti settling agent 5 parts by weight Anti skinning agent 0.1 parts by weight Zinc Octoate 2.0 parts by weight

5.3 High Gloss Enamel-Cream Colour:

 

Titanium Dioxide 100 parts by weight Silac V 20 372 parts by weight Aluminium Stearete 2 parts by weight Anti Skinning agent 0.04 parts by weight

Add recommended quantity of Driers and solvent.

5.4 Anti Corrosive Primers:

 

Aluminium Powder (66%) 20.0 parts by weight Basic Lead Sulphate 40.0 parts by weight Iron Oxide 20.0 parts by weight Barytes 20.0 parts by weight Silac V 30 150.0 parts by weight Naptha solvent 1.60 parts by weight

Add recommended quantity of Driers and Solvent.  

5.5 Aluminium Paint:

 

Silac V 20 D 10 parts by weight MTO 10 parts by weight Silicone surfactant 0.1% parts by weight

Add more driers, as required with leafing Aluminium paste 2 Kg separately packed.

5.6  Olive Green Enamel:

 

Green Chromium Oxide 10.0 parts by weight China Clay 6.0 parts by weight Carbon Black 0.2 parts by weight Middle Chrome 0.6 parts by weight Silac V 30 20.0 parts by weight Wetting agent 0.2 parts by weight

In the above composition add solvent and driers as may be required.

5.7 Air Drying insulation varnish:

 

Silac V 20 60 parts by weight DCO or Linseed Stand oil 14 parts by weight Xylene/MTO mixture (1:1) 40 parts by weight

In the above compositions add solvent and driers as may be required.

 

6.0 Technical Service

We have well equipped Development laboratories and are in a position to provide detailed Technical guidance and suggestions in regard to the application of these products.

Caution: Because we cannot anticipate the conditions under which our product may be used, we do not guarantee the applicability or the accuracy of the above information. Users should make their own tests to determine the suitability of our products for their particular purpose. The products are sold without any such warranty either express or implied. Moreover the above information is not intended as recommendation, to use our product in the infringement of any patent.