Rheological modifiers and defoamers from renewable sources for the formulation of bio-based paints

 Luca Amadeo, Chiara Mantovani – SAFIC ALCAN ITALIA
Henry Meadowcroft – SCOTT BADER
Katrin Sondergeld – ICL / BK-GIULINI

The bio-based concept
Products in which at least a portion of material derives from renewable sources can be defined as bio-based. This portion can, for example, derive from corn or sugar cane, while the remaining parts can derive from fossil coal. The use of renewable sources leads to obtaining materials that generally have a lower impact on the production of CO2 (directly responsible for climate change and extreme weather events), so in recent years there has been an increase in the search for bio-based materials that can match the characteristics of materials deriving from petroleum, so as to replace them and reduce carbon dioxide emissions.
The biomass used to manufacture bio-based polymers comes from various activities such as agriculture or the agri-food industry. Depending on the origin of the biomass used for production, it is possible to identify three categories: products deriving from the food industry, from waste (recycling concept) and from microorganisms. To date, the main renewable resources used for the production of bio-based products are cereals and sugars.
The concept of bio-based has exploded in recent years, but there were already several products normally on the market, just think of artificial fibers such as viscose and acetate, all derived from cotton. Today, in the popular imagination, bio-based is instead associated with the replacement of polymers deriving from petroleum with those from renewable sources. In most cases they can be chemically similar to those usually used.
In the Coating world, the largest volumes are represented by binders and solvents, on which many producers and users are working and investing. However, we must not forget additives, absolutely necessary for the completion of any formulation.

Bio-based and pH independent inverse emulsion rheological modifiers
Scott Bader is a British multinational with over 100 years of history and experience in the production of polymers and solutions for the most varied industrial sectors. Today it employs 800 people in 7 production sites and 18 offices around the world. In the coating sector, it offers the market with Texicryl® acrylic, styrene-acrylic dispersions and alkali-soluble rheological modifiers, as well as with the innovative Texipol® inverse emulsion thickeners. Texipol® range includes two bio-based rheological modifiers with pseudoplastic behavior and pH-independent activity:
– Texipol® 63-513: inverse emulsion thickener with 20% bio-content from cane sugar
– Texipol® 63-516: inverse emulsion thickener with 20% bio-content from vegetable sources and completely VOC-free
Inverse emulsion technology involves the emulsification of a physically expanding polymer in an oil-based carrier. In contact with water, the emulsion is inverted, and the polymer is free to expand generating thickening. These products are effective in a pH range from 2 to 12 (3 to 10 to be precise in the case of bio-based grades).

Alternative rheological modi-fiers to cellulose ethers from tamarind seeds
The tamarind is a rapidly developing tree that can be grown on practically any type of soil in the temperate and tropical belt, from South America, through Mexico, Africa, South Europe, India, down to South-East Asia. A poor and robust tree, which contains in its seeds the secret of the success of Schützen Cchemical Group. In fact, the Indian company is leader in the development and production of truly sustainable, non-toxic, biodegradable and industrially feasible bio-based materials, among which the rheological modifiers derive precisely from tamarind seeds.
– Schutzencol PC-80: high molecular weight polysaccharide, poorly anionic, with pseudoplastic thickening effect; it is particularly indicated as an alternative to cellulose ethers, compared to which its ability to maintain a stable in-can viscosity stands out even after several months from the production of the paint
– Schutzencol-952: polysaccharide derived from tamarind seeds, developed to be the perfect alternative to cellulose ethers used as thickeners in the formulation of tile adhesives; the product gives compactness to the adhesive (no-sagging) and guarantees a very long open-time for processing, as well as high mechanical strength.

From rapeseed to bio-based and ECOLABEL defoamers
German technology and multinational vocation, these are the keys to the success of BK-Giulini GmbH coating additives, leader in the sector with its Polyron® inorganic dispersants, Lopon® dispersants, Targon® additives for dry-mix and Phos-Chek® flame retardants.
For its defoamers, BK-Giulini had no hesitations and from the outset it only chose the path of sustainability, with products derived from rapeseed oil and other renewable sources:
– Lopon® E81: universal defoamer for water-based paints and varnishes
– Lopon® E13: specific defoamer for low viscosity formulations
– Lopon® E100: defoamer developed for glossy enamels
The demonstrated effectiveness of these additives is accompanied by the total absence of mineral oil, silicones and VOCs. Last but not least, Lopon® defoamers can be used for completely ECOLABEL formulations.
Safic Alcan Italia is the exclusive distributor in Italy for Scott Bader polymer dispersions and thickeners, Schützen thickeners and BK Giulini GmbH / ICL Phosphate Specialties coating additives.

Safic Alcan is a French specialty chemicals distributor based in Paris. The company develops and supplies a wide range of polymers, materials and additives for rubber, coatings, adhesives, thermoplastic industries, polyurethanes, lubricants, detergents, cosmetics, pharmaceuticals and nutraceuticals. With a network of 32 strategically located locations in Europe, Middle East, North America, Asia and South Africa, the company represents cutting-edge manufacturers around the world.
Its highly skilled sales engineers enable the company to provide dedicated technical expertise and high-performance solutions, thus creating long-term partnerships with the majority of customers. The company employs 700 people worldwide and generated a turnover of over 900 million Euros in 2022.


Other news

Di Luca Amadeo, Chiara Mantovani – SAFIC ALCAN ITALIA / Henry Meadowcroft – SCOTT BADER / Raj Tanna – SCHÜTZEN CHEMICAL GROUP / Katrin Sondergeld – ICL / BK-GIULINI
Di Dimitri Leroy / Stefan Priemen - HUNTSMAN