Paint Raw Material Evaluation for Global firm

SITUATION:

A global company with multibillion dollar sales required an independent paint raw material evaluation from a paint expert of the performance and application potential of a new fluoropolymer resin that they had developed.

ACTION/RESULT:

Due to the resident coating expertise in fluoropolymer coatings, the supplier contracted Chemical Dynamics to provide an independent evaluation of this new resin chemistry. Chemical Dynamics completed the evaluation and identified multiple new applications for the fluoropolymer resin chemistry.

Hydrophobic Pigments to Avoid Flooding & Floating

Dispersing and Wetting Hydrophobic Pigments and Fillers in Water Based Paints to avoid Pigment Flooding and Floating

A critical part of any coatings formulation is ensuring that the coating will be free of inherent defects, including pigment flooding and floating. Waterborne formulations represent some unique challenges due to multiple factors, including the high surface tension and polarity of water that does not contribute to the wetting of most pigment and filler particles. In this article, I’ll define some important considerations in formulating waterborne paints to avoid pigment flooding and floating.

Flooding, Floating, Surface Tension, Bernard Cells, Flocculation and Agglomeration

Floating describes a mottled, splotchy appearance on the surface of a paint film. It is most apparent in coatings colored with two or more pigments and is a result of the horizontal separation of different pigments. Flooding is the phenomena observed when the surface color of an applied film is uniform but is darker or lighter than it should be. This is attributed to a vertical separation of different pigments in the film.

Vertical Separation of Pigment - Horizontal Separation of Pigment
Vertical Separation                           Horizontal Separation

Surface Tension results when the force that occurs in a liquid at the interface differs from the forces within the liquid. Thus, surface tension is caused from the surface molecules having a higher free energy than those molecules in the bulk of the liquid.

Surface tension differential can cause a convection current resulting in a regular hexagonal surface pattern called Benard Cells. A hexagonal Benard Cell pattern results in smaller, more mobile pigment particles (smaller, less dense) being deposited on the perimeter and the less mobile particles (larger, more dense) remaining away from the perimeter.

Figure 2 – Rub-up of Flocculated Blue Pigment
Figure 2 – Rub-up of Flocculated Blue Pigment

Flocculation is the recombination of dispersed pigment particles that were not properly stabilized in the pigment dispersion. Flocculation is undesirable at it detracts from hiding and color development. Flocculation is reversible by applying a low degree of shear. In figure 2, the phthalocyanine (EU) blue pigment is flocculated. Upon rubbing with a finger, the deeper blue color returns.

Stabilized pigment dispersion -- Flocculated pigment dispersion
Stabilized pigment dispersion — Flocculated pigment dispersion

Pigment agglomeration is defined as pigment particles that are clumped together without sufficient vehicle or wetting agents present between pigment particles. When agglomeration occurs, extensive shear and attrition forces are usually necessary to reinstate a stabilized pigment dispersion.

 

To read the full article about Remedial Actions to Overcome Floating and Flooding in Waterborne Paints, click here.

Paint and Coating Failure Analysis

CHALLENGE: A national steel company that supplies coated product to the building industry received multiple complaints that the 20 year warranted coated product they supplied showed severe dirt staining once put into service on commercial and industrial buildings.

ACTION: Chemical Dynamics as an expert paint consultant in paint failure analysis was called upon to inspect several representative building sites where samples were taken, tested and paint and coating failure analysis were conducted.

RESULT: Chemical Dynamics was able to demonstrate that the unexposed coating rapidly degraded when exposed to accelerated weathering resulting in increased susceptibility to dirt staining and loss of hardness. As a result of our analysis and testing the paint company accepted responsibility for the failures saving our client several hundred thousand dollars in claims.

Certified Green Claims Increase Value & Brand Recognition in Coatings

Article written by Chemical Dynamics President, Ronald Lewarchik, originally published in UL Prospector.

Whether coatings are sold directly to consumers or business to business, UL’s study: Under the Lens: Claiming Green – The influence of green product claims on purchase intent and brand perception reveals that legitimate third-party, certified green claims contribute to the attractiveness of a product and command a higher price because of enhanced brand perception. The survey results are noteworthy, as 70% of Americans say they’re searching for greener products, and 67% of business decision makers indicate sustainability is an important factor when making decisions for their organizations.

Avoiding Misleading Claims

However, many manufacturers misrepresent their products by claiming they are green for the purposes of enhancing sales. In 2012, the Federal Trade Commission revised its Green Guides, the agency’s core set of guidelines to help marketers avoid making misleading environmental claims. The Guides are now more specific and prescriptive, making it easier for the FTC to prosecute “greenwashers.” Accordingly, if a green claim is considered to be deceptive in the eyes of the FTC, there is both a financial and a legal risk.

Read the full article here.

Roof Coating Analysis

CHALLENGE:

A national distributor of painted metal roofs encountered peeling paint on several residential and public buildings. The roof coating had a 20 year warranty against peeling provided by the paint supplier, but the paint supplier failed to honor the warranty, citing a defect in the painting process rather than faulty paint. Consequently, this would have resulted in multiple law suits and multimillion dollar claims against our client.

 

ACTION:

As a paint consultant, Chemical Dynamics inspected multiple sites where peeling paint was evidenced, samples were taken and roof coating analysis and testing completed.

 

RESULT:

Chemical Dynamics was able to show that the failures were caused from faulty paint formulations that when exposed to the elements resulted in soft coatings that failed adhesion. Accordingly, our client was able shift the responsibility to the paint supplier to pay the claims.

Paint and Coating Failure Analysis

CHALLENGE:

A century old government building, constructed of concrete, was in need of painting. Upon removal of the old paint, a reoccur-able, unpaintable powder continued to resurface on the building. The client had explored this issue with many paint companies and other paint consultants, but none of them could not explain the phenomena.

 

ACTION:

On short notice, Chemical Dynamics performed an onsite inspection and collected representative samples of the residue. The team performed a paint and coating failure analysis of the soluble components of the residue.

 

RESULT:

Chemical Dynamics was able to demonstrate that the powder residue is a result of secondary efflorescence of the concrete.  Secondary efflorescence is the result of concrete degradation and the migration of water soluble salts to the surface of the concrete.  With the proper diagnoses of the problem, Chemical Dynamics was able to recommend corrective action.

Hydrophobic Clear Glass Coating

CHALLENGE:

A premium supplier of coated glass paint products desired a glass coating that provided long lasting rain repellency when applied to clear window glass for use in automotive and residential applications.

 

ACTION:

Chemical Dynamics’ coatings product development group developed a clear coating that is easy to apply and provides long lasting rain repellency.

 

RESULT: 

Glass coated with this product exposed to rain or water droplets will quickly shed water droplets so little or no water will remain on the glass.

Understanding Corrosion Inhibitive Pigments

The annual cost of steel corrosion is estimated to be over $400 billion in the United States and $2 trillion globally. Corrosion is a process where the metal can be degraded by electrochemical and/or chemical processes. This article will discuss the use of lead- and chrome-free corrosion inhibitive pigments in coatings where corrosion is primarily from electrochemical processes. Accordingly, the correct use of corrosion inhibitive pigments can be of enormous economic value.

Ron Lewarchik is a contributing author to UL Prospector and publishes articles monthly. Please read on for his expert findings on “Understanding Corrosion Inhibitive Pigments”:

Metals desire to be in their most thermodynamically stable state, which, in simplified terms, is the naturally occurring state of matter in its lowest energy state. Metals ordinarily exist naturally as oxides (e.g. iron oxide, aluminum oxide, zinc oxide, because oxides represent their lowest energy state. Corrosion is an electrochemical deterioration of a metal due to the reaction with its environment to transform the metal into its lowest energy state. Oxidation occurs at the anode (positive electrode) and reduction occurs at the cathode (negative electrode). Corrosion is normally accelerated by the presence of water, oxygen and salts (particularly of strong acids).

Click here to read on for the full article at UL Prospector 

Flow, Leveling & Viscosity Control in Waterborne Coatings

Ron Lewarchik is a contributing author to UL Prospector and publishes articles monthly. Please read on for his expert findings on “Flow, Leveling & Viscosity Control in Waterborne Coatings”:

Flow, leveling and viscosity stability can be very challenging and problematic in waterborne ambient cure and baked finishes. These issues can affect not only package stability, but also have a profound effect on appearance during and after application. As the vast majority of waterborne coatings are anionic in nature (amine (EU) neutralized), this article will focus on amine neutralized resin types, although if resin polarity, for example from acid functionality, is high enough, anionic resin types can be dispersible or even water soluble without the use of neutralizing amine.

There are two major categories of waterborne paint technologies: water reducible (EU) and latex (EU). For the purpose of this article, water reducible resins are normally made in solvent and then reduced with water to form a resin dispersion in water. Latex resins are made by emulsion polymerization in water. The paints using emulsion resins most often utilize a small amount of organic cosolvent to improve coalescence of the latex particles, as well as substrate wetting.

Other types of waterborne paints utilize a growing number of resin types that include PUD (polyurethane dispersions (EU)) as well as microemulsions. Accordingly, multiple issues can influence the flow, leveling, and appearance of waterborne coatings. This article will primarily examine the impact of 1) resin type, 2) humidity and temperature variation, 3) wetting and 4) flow control. Appearance of the coating during and after application can be affected greatly by these issues.

Click here to read on for the full article at UL Prospector 

Improving Performance in Ambient Cured Latex Paints

Ron Lewarchik is a contributing author to UL Prospector and publishes articles monthly. Please read on for his findings on “Improving Performance in Ambient Cured Latex Paints”:

Many ambient cured latex paint systems offer deficient properties to those of their solvent born counterparts. Issues with water-born, latex-based paints (EU) may include poorer chemical resistance, moisture resistance, adhesion, surface hardness, abrasion and block resistance. Latex-based coatings systems where these characteristics are desired include architectural, automotive interior, business machine coatings, general industrial, implement finishes and wood coatings.

This article will summarize the causes of poorer performance in ambient cured water-born coatings (EU) and provide formulation guidance and the means to improve performance. We will concentrate on aspects involving the use of commercially available latex polymers (EU) and cross-linkers (EU), rather than on improving these properties by varying monomer selection, polymer architecture (e.g. core-shell, dispersion, solution, emulsion or microemulsion etc.) or Tg (the glass transition temperature is the temperature at which a polymer changes from a hard and brittle state to soft and pliable).  Click here for the full article at UL Prospector