BEHR BOASTS NANOPARTICLE EXTERIOR COATINGS FAR SUPERIOR TO PRIME AND TOPCOAT SYSTEMS

BEHR BOASTS NANOPARTICLE EXTERIOR COATINGS FAR SUPERIOR TO PRIME AND TOPCOAT SYSTEMS

PATENT PAINTS BRIGHT FUTURE FOR NANO ZINC PIGMENTS

At 4 to 20 pounds of inorganic oxide nanoparticles per 100 gallons of exterior paint, Behr is sure to brighten the new year prospects of nano pigment manufacturers. Behr has developed a one coat system for the exterior of buildings that can replace the old prime and paint system with long lasting coatings that resists environmental degradation.

Nanophase’s proprietary nanoparticles are now being used in Behr’s Premium Plus Ultra paint. Nanophase’s nanoparticles not only lend the paint improved adhesion and anti-mildew properties, but also allow users to forgo the normal two-step priming and coating process. The new paint reportedly does both in a single step.

In U.S. Patent 7,642,309, Behr Process Corporation (Santa Ana, CA) reveals paints that provide coatings with improved properties such as, tannin blocking, hiding power, stain removal, corrosion resistance and which have high adhesion. Research results show it to be far superior to competing commercial products now on the market .

The formulations basically include two binders, a zinc oxide nanoparticle pigment, and pigmentary titanium dioxide, according to Behr inventors Ming-Ren Tarng, Mark Minamyer, Anh Pham, Stan Brownell, Annie Pham, Anil Alexander, Deven Shah, Kim L. Nguyen, My Linh Pham and Sidney Maxey, who detail a range of coating compositions with inorganic oxide nanoparticles in U.S. Patent 7,642,309.

All nano paint formulations exhibited improvements in adhesion, tannin blocking, stain removal, hiding power, color retention and corrosion resistance when compared to commercial products now on the market.

Nanoparticle-sized metal oxide pigments are used. According to Behr, in a general formulation, the paint is comprised of: an acrylic primer binder in an amount of 340 to 430 lbs per 100 gallons of paint; an acrylic topcoat binder in an amount of 70 to about 100 lbs per 100 gallons of paint; a styrene acrylic topcoat binder in an amount greater than 0 to 180 lbs per 100 gallons of paint; titanium dioxide in an amount greater than 0 to 350 lbs per 100 gallons of paint; zinc oxide in an amount greater than 0 to 7 lbs per 100 gallons of paint; and a nano particle inorganic oxide in an amount 4 to 20 lbs per 100 gallons of paint

FIG. 1 depicts a multi-axis property graph of the test results of Behr’s paint having a satin sheen and white base, as compared to commercially available exterior satin in a white base. 

FIG. 1 depicts a multi-axis property graph of the test results of paint of the present invention having a satin sheen and white base, as compared to commercially-available, exterior satin in a white base. Adhesion, yellowing, stain removal, hiding power, scrub resistance, corrosion, and tannin blocking were measured.

Paint Manufacturing 101

Traditionally consumers have had to choose between the superior durability offered by latex paints and the superior hiding properties of oil-based paint. Conventional latex or emulsion paints require an underlying primer coat prior to their application to provide an adequate level of blocking and to prevent bleed-through, such as of tannins.

In addition, many conventional latex paints require a primer coat to provide adequate adhesion and durability for specific applications. Often, even when a primer is applied, multiple coats of the prior art paints are required to prevent an alteration of color due to the presence of the primer or bleed through of dyes and pigments from the underlying substrate. In fact, multiple applications of prior art paint will not prevent bleed-through on substrates such as cedar since the dyes and pigments, such as tannins contained in the substrates, are often water soluble and diffuse through each layer of the latex paint.

Paint typically contains four essential ingredients, namely pigment, binder, liquid and additives. Any or all of these ingredients may be a single component or may comprise multiple items. Pigment provides color to paint and also makes paint opaque, and pigment is usually of mineral or organic origin although some pigments are artificially produced.

Some pigments possess little or no bulk and must be fixed on a more solid, but at the same time transparent, substance or base. "Prime" pigments provide color and opacity (opaque coverage). The most common prime pigment is titanium dioxide, which is white and is used in latex and oil-based paints.

Traditionally, pigments have also added hiding properties to paint. Specialty or extender pigments may also be used and provide bulk to the paint at a low cost. The extender pigments are often chosen for their impact on properties like scrub resistance, stain resistance and chalk resistance. Alum or clay are frequently used for this purpose.

These pigments are added to the paint to provide certain characteristics such as thickness, a certain level of gloss and durability. They are usually naturally occurring products which originally were in the earth and were mined and purified for use in paint. Such pigments as calcium carbonate, talc and clay are, for example, used extensively in paints.

The binder holds the pigment and also adheres it to a surface, and a binder composition may have more than one component. In latex paint, the latex resin is the binder. Most commonly in latex paint, the binder is 100% acrylic, vinyl acrylic (polyvinyl acetate), or styreneated acrylic.

The pigment particles are insoluble and merely form a suspension in the binder. The binder "binds" the pigment into a tough, continuous film and as noted above helps the paint adhere to the surface. In addition, it has been found previously that the use of 100% acrylic binder provides for maximum adhesion when wet and also provides for resistance to blistering and peeling, resistance to mildew and dirt, and alkali resistance for paint applied over fresh masonry.

Liquids carry the pigment and binders, and this liquid is the part of the paint or coatings product which evaporates. The role of the fluid is to keep the paint in a fluid form for ease of application. Once applied to the surface it evaporates leaving a uniform film which then dries to form a protective coating. The liquid used is primarily determined by the solubility of the binder. In oil-based and alkyd paints, the liquid is typically a paint thinner, and in latex paints, the liquid is typically water. Traditionally, top quality paints have less liquid and more solids (i.e. pigment & binders) as measured by percent solid.

Additives are ingredients used at low levels to provide key properties, such as but not limited to: mildew resistance, better flow and leveling, and splatter resistance. Common additives used in conventional paint formulations include rheology modifiers, surfactants, defoamers, coalescents, and biocides. Other numerous additives are well-known in the art and may be utilized as required to formulate a paint having the desired properties.

Various techniques are known in the art for producing paints having various types of sheens, i.e. "shine" or gloss. For example, by incrementally increasing pigment levels and/or by using larger pigment particles, various gloss levels can be achiev