Waxes are commonly used in the formulation of paints, coatings, and inks to enhance and protect their appearance, feel, slip, abrasion resistance and overall durability. These wax additives are available in multiple forms and feedstocks and are either naturally-occurring or synthetic.
Plants produce their own waxes to protect their leaves or seeds from environmental forces. These protective properties of natural waxes can also be used to deliver some outstanding benefits to coatings and inks. Purification or slight chemical modification may be necessary to enhance properties.
Carnauba-type waxes are purely plant-based (from the leaves of the carnauba palm) and have been popular for many years, especially in packaging applications where they provide slip, scratch and abrasion resistance, gloss retention, and release properties. More recently, additional types of naturally-derived waxes have been growing in popularity due to sustainability considerations—shrinking the CO2 footprint and using raw materials from renewable resources. There are waxes derived from the leaves of the Candelilla shrub, sunflower seeds, soy, sugar cane bagasse or extracted from the bran oil of rice (see the chart below). Natural waxes can also be derived from animals and insects (like beeswax).
Properties of natural waxes vary from synthetic waxes, as the chemical composition is different, and ratios of components are subject to variation. Melting points of natural waxes tend to be lower than melting points of synthetic waxes like PE or PP waxes and more polar functional groups are present. So it can be challenging to replace synthetic waxes with natural waxes while maintaining similar performance. But there are significant benefits as well.
In more and more printing and packaging applications (i.e., food packaging), inks need to be biodegradable and enable compostability or recyclability of the packaging material. Natural waxes are great for this application. They are also growing in use in the coatings market due to industry drivers to enhance sustainability. This trend is particularly strong in the wood coatings industry. Unlike food packaging applications, other paint and coating applications require the coatings to last a long time, as they are designed to protect materials and enhance their lifetime usefulness.
Property Profiles of Different Wax Types
|Wax Type||Melting point (°C)||Source||Composition|
|Carnauba||82-86||Leaves of the carnauba palm||Aliphatic esters (40%), aromatic esters (21%), free acids (13%), and fatty alcohols (12%), C26-C30 range.|
|Rice Bran||77-86||Extracted from the bran oil of rice||Aliphatic acids (C16-C24) and alcohol esters (C26-C30), free fatty acids (palmitic acid), squalene and phospholipids.|
|Sunflower||74-80||Grinding unpeeled seeds||Esters of C16-C24 fatty acids and C26-C32 alcohols.|
|Sugar Cane||75-80||Sugar cane bagasse||About 70% alcohols C18-C32, wax acids C18-C32, ω-hydroxycarboxylic acids and aromatic carboxylic acids, about 5-10% unesterified diols, long-chain wax acids C22-C30.|
|Candelilla||68.5-72.5||Leaves of the Candelilla shrub||Hydrocarbons (50%, C29-C33), esters (20-29%), free acids (7-9%), and resins (12-14%).|
|Soy||49-82||Soybean oil, hydrogenated||Triglyceride, containing a high proportion of stearic acid.|
Lubrizol Natural Waxes
Lubrizol currently offers Carnauba wax additives as micronized powders or in dispersions and emulsions as well as amide waxes, which are approx. 95% bio-based.
In addition, we are currently leveraging our extensive experience in micronized and liquid wax preparations for coatings and inks to develop other natural, bio-based waxes. Several new products based on rice bran wax are showing great promise to offer similar performance to polyethylene waxes. Lubrizol is also testing candelilla wax, sunflower wax, sugar cane wax and soy wax and can work with customers to develop specific grades.
Apart from naturally derived waxes, Lubrizol is also exploring the capability of non-fossil based synthetic PE or PP waxes made of mass balance-certified ethylene and propylene from renewable feedstocks. This is another viable opportunity to enable more sustainable additive solutions.
Contact a Lubrizol expert to discuss the latest status and availability of our natural and renewable waxes, or to hear about the specific properties of new commercially available grades.