corrosion control without the use of heavy metal toxins
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1st Annual Eastern Coatings Show & Conference 2013
Atlantic City, NJ
Corrosion Control Without the Use of Heavy Metal Toxins
A Division of ICL Performance Products LP
Challenges in the Corrosion World
Overview
1
2
3
4 Heavy Metal Free Organic Corrosion Inhibitor
Heavy Metal Free Inorganic Corrosion Inhibitor
Background on Corrosion
5 Hybrid Technology
6 Summary
Corrosion Inhibitors
Chromate salts
Zinc salts
Barium salts
Nitrites & Nitrates
Risk (Humans) High Low Low High
Risk (Environment) High High
Aquatic toxin Harmful if inhaled
or swallowedHigh
Challenges in the Corrosion World
1.
2. 3.
Iron Substrate Anodic Region Cathodic Region
Water Droplet
2 Fe 4 e-
4 H+ O2
2 H2O n H2O
3/2 O2
2 Fe2+
Fe2O3 . H2O
Rust
CORROSION CELL DIAGRAM
1. Oxidation of Fe yields electrons which travel through the metal. 2. Electrons at the Fe (inactive) cathode reduce O2 to H2O. 3. The Fe2+ migrates through the drop and reacts with O2+ and H2O to form rust.
Types of Corrosion
Flash Rust
Galvanic
Filiform
Rapid, widespread corrosion seen during initial application.
Contact between two alloys which promotes oxidation of the less noble metal.
Differential aeration promotes this unique form of corrosion.
Of concern in coatings…
Lambourne, R. (1999); Paint and Surface Coatings: Theory and Practice, 2 ed. (Lambourne, R. and Strivens, T.) England: William Andrew Publishing
So Many Choices
Identifying the correct inhibitor quickly can save you time and money
Direct Active
Indirect Ion- Scavenging
Organic
NON-TOXIC HEAVY METAL FREE ANTICORROSIVE PIGMENTS
Description Composition Anticorrosive Mechanism
Ions released
End Use Coatings
Applications
Inorganic A Calcium Borosilicate
Anodic passivation & Saponification
Calcium & Borate
Solvent borne, High Solids, 100% solids
Inorganic B Calcium Phosphate
Magnesium, Aluminum
Double Layer Hydroxide
Cathodic passivation &
anion exchange
Calcium, Phosphate
& Carbonate
Water-borne, Solvent borne,
High Solids, 100% solids,
Powder coatings
+
+
+
+
+
+
-- --
--
+
-
M(PO4)2
+
-
Hydrolysis
Anode
Insoluble FePO4
Cathode e-
Fe2+ H2O
Precipitate Mx(OH)x
Substrate Fe
Passivation Mechanism Active-Direct Inhibitor
Paint Film
Inorganic B – Dual Mechanism
SUBSTRATE
PASSIVE OXIDE LAYER
+
+
+
+
+
+
+
-- --
--
+
-
H2O Cl-aq
+ O+O+ O + O+ O
+ O +O +
O+
O+
O
O2
O2
+O
O2
Cl-SO4
2-
SO42-
aqH2O
+
Passivation
Ion Scavenging
Active Anti-Corrosive Pigment Mechanisms
NON-TOXIC HEAVY METAL FREE ANTICORROSIVE PIGMENTS
SEM (1000×) for Inorganic B showing platy morphology
2K Solvent-borne Epoxy Primer on Hot Rolled Steel Dry Film Thickness: 4.0-4.5 mils (100-113 microns)
Sample Salt Spray (Hours)
PVC (%) Blistering Field Scribe
Creep (mm) Scribe Rating
Blank Control 1995 40 2-6M 8G 2-6 5 10% Zinc Chromate 1995 40 8F 10 1-2 5.5 10% Zinc Phosphate 1995 40 10 9G 1-2 7
10% Inorganic B 1995 40 10 8G 0.5-1 8
STATIC SALT SPRAY ASTM B117 1995 HOURS
Blank Inorganic B Zn Chromate Zn Phosphate
HEAVY METAL FREE ORGANIC CORROSION INHIBITOR
Description Composition Anticorrosive Mechanisms Function End Use Coatings
Applications
Organic A Amino
Carboxylate
Anodic Long-term, flash rust & in can rust
inhibitor, adhesion
Water-based Acrylics,
Polyurethane, Alkyds
Organic B Organic Acid
Amine Complex
Anodic Long- term, flash rust, adhesion
Water-based Acrylics,
Polyurethanes, UV, Polyester Alkyds
Galvanic Corrosion Inhibition
Flash Rust Inhibited
Galvanic & Flash Rust Inhibition
Uninhibited
Sodium Nitrite
Organic Inhibitors
Weld Seams
Galvanic & Uniform Corrosion
An additive for protective primers (S/B & W/B) General primers High gloss DTM Wash primers Clear coats
Liquid adhesion promoter & corrosion inhibitor Excellent for white rust mitigation on HDG Excellent for black rust mitigation on Galvalume
BENEFITS
Substrate: CRS DFT: 1.7 mils Salt Spray- 336 hrs
Gloss: 20°- 59.8 60°- 83.7
Gloss: 20°- 38.5 60°- 78.5
5% Inorganic A 2% Hybrid 2% Organic A 5% Inorganic B Blank
SUMMARY Non-toxic heavy metal free inorganic and organic corrosion inhibitors can be used in place of heavy metal based products such zinc phosphate and zinc chromate.
Performance achieved by these products meets or exceeds that of heavy metal products in solvent-borne and water-borne coating applications.
Key to this success is to capitalize on the multi-mechanism aspects of the new technologies namely, the combination of passivation, ion exchange, and barrier enhancement.
NOTICE: Although the information and recommendations set forth herein (hereinafter “information”) are presented in good faith and believed to be correct as of the date hereof, ICL Performance Products LP (“ICL”) makes no representations or warranties as to the completeness or accuracy thereof. Information is supplied upon the condition that the persons receiving same will make their own determination as to its suitability for their purposes prior to use. In no event will ICL be responsible for damages of any nature whatsoever resulting from the use or reliance upon information or the product to which information refers. Nothing contained herein is to be construed as a recommendation to use any product, process, equipment or formulation in conflict with any patent, and ICL makes no representation or warranty, express or implied, that the use thereof will not infringe any patent. NO REPRESENTATIONS OR WARRANTIES, EITHER EXPRESSED OR IMPLIED, OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR OF ANY OTHER NATURE ARE MADE HEREUNDER WITH RESPECT TO INFORMATION OR THE PRODUCT TO WHICH INFORMATION REFERS. © 2013 ICL Performance Products LP. All rights reserved.
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