TAGS: Sustainability/Natural Coatings Industrial Coatings
The current annual value of the global industrial coatings market is about 82 billion Euros with a projected increase in value up to 104 billion Euros within the decade. This presents a substantial opportunity for the use of biomaterials.
The broad range of applications, economic factors, and performance requirements encompassed within industrial coatings provides many niches where novel sustainable raw materials may be incorporated. End uses for industrial coatings run the gamut from high-performance aerospace and marine finishes to product finishes for everyday objects such as furniture and small appliances.
The raw material technologies utilized range from low solids alkyd resins to 2K epoxy and urethane systems. Let's explore coatings ingredients and formulation strategies utilizing biomaterials.
Range of Biomaterials for Coatings
Throughout this article, I am going to use the term biomaterials as a shorthand for
bio-based raw materials. This includes materials derived from both plant and animal sources, but only plant-based products are widely used as coatings ingredients. There are many biomaterials suitable for use in industrial coatings. When choosing formulation ingredients, consider the sources of starting materials.
Biomaterials made from non-food crops or industrial wastes, for example, from paper making, are preferred. The variation in technical and price/performance metrics within industrial coatings lends itself to formulating using a large assortment of raw materials. Some types of coatings ingredients using biomaterials include the following:
- Polymeric binders,
- Solvents, and
- Pigments.
Polymers and Binder Systems with Biomaterials
Polymers and binder systems are the backbone of a formulation and determine the primary performance properties of an industrial coating. The most common example of a binder system incorporating biomaterials is also one of the oldest.
Alkyd resins based on biomaterials, such as linseed and soya oils, were one of the first widely utilized binders for coatings ranging in purpose from architectural to automotive. Many industrial coatings are still based on alkyd technology especially in lighter duty applications.
Waterborne alkyd dispersions are a way to combine low VOC attributes with biomaterials to meet modern needs with proven chemistry. When modified with acrylics or urethanes, the performance and application flexibility is greatly enhanced. Several suppliers, including allnex, Worlée, and ASK Chemicals have listings for these materials on the SpecialChem database.
Many other types of polymer binders for industrial coatings incorporating biomaterials are commercially available. These include acrylic, urethane, and epoxy resins.
Acrylics Containing Biomaterials
A very exciting development is
Decovery® SP-7450 supplied by Covestro. Following are its features:
- This acrylic copolymer emulsion boasts 39% bio-based content.
- It is purpose-built for exterior industrial wood finishes.
Non-yellowing clear and opaque coatings made with Decovery® SP-7450 have excellent adhesion, flexibility, and water resistance.
View bio-based acrylic resins »»
Polyurethanes Synthesized from Biomaterials
Polyols for baking enamels and 2K urethane coatings are another coating technology ripe for the inclusion of biomaterials. Suppliers, such as
Alberdingk Boley and others, offer a wide range of polyols which can be cross-linked with isocyanates or amino resins.
Even cross-linkers like isocyanates and polyamines can be synthesized from biomaterial feedstocks.
Desmodur® eco N 7300 is an aliphatic isocyanate containing
68% bio-based material by weight. Weather and chemical resistant urethane industrial coatings can be easily formulated from Desmodur® eco N 7300 utilizing a wide range of solvents for application versatility.
View bio-based polyurethane resins »»
Epoxies Crosslinked with Biomaterials
Two-part epoxy coatings can also be cross-linked with biomaterial-based components. Cashew nutshell liquid (CNSL)-based modified phenalkamide
Cardolite® LITE 2001X9 epoxy curing agent imparts following properties:
- rapid cure response,
- good adhesion to poorly prepared surfaces, and
- excellent corrosion resistance to industrial, marine, and protective coatings.
View bio-based epoxy resins »»
Introducing Biomaterials as Solvents and Coalescents
Biomaterials can be used as
solvents and
coalescents in coatings. An early example of this was turpentine distilled from pine tree resins which has been used to reduce the viscosity of paints and varnishes since the 1500s. Developments in chemical processing techniques and bioreactors have enabled the manufacturing of a variety of solvents suitable for coatings use derived from bio-based feedstocks.
Vertec Biosolvents offers a wide selection of 100% bio-based solvents which can be substituted for petroleum-based solvents. Parameters, such as
evaporation rate, solvent power, and flash point for any fossil fuel-based solvents can be matched with a bio-based solvent made from renewable feedstocks like corn, soybeans, and citrus.
Future of Incorporating Biomaterials in Pigments
Pigments might not be the first component of a coating that comes to mind when thinking of biomaterials, since many common pigments are nonpetroleum derived inorganic compounds. Especially for industrial and automotive coatings bright colors made with organic pigments are more prevalent than in architectural coatings. This opens an opportunity to incorporate biomaterials in a new way.
To date, only one pigment manufacturer Heubach (formerly Clariant) has brought a commercial organic pigment
VYNAMON® Red 325401 (PR 254) to market, but other suppliers will surely follow their lead. While not thought of as an organic pigment,
carbon black (PB 7) is normally made from fossil fuels. A bio-based alternative to conventional carbon black pigments made from oil or gas is
BioBlack from Nature Coatings. Made from wood waste,
this high-performance black pigment is suitable for coatings and inks.
Check out the complete list of bio-based pigments here»»
Formulation Strategy - Industrial Coatings with Biomaterials
Your strategy for formulating industrial coatings with biomaterials will change based on the motivations for using biomaterials. Three drivers encouraging the utilization of biomaterials are:
- Regulations: Governmental initiatives such as the European Green Deal drive the implementation of biomaterial-based coatings across many countries. These programs require quantitative certification of biobased content in order to meet the guidelines. When formulating to meet a governmental requirement careful attention must be paid to material origins and accounting for the chain of custody during shipping and manufacturing. These are as much a legal responsibility as hazardous waste reporting or certifying environmental data.
- NGO/Voluntary Certifications: Voluntary certifications such as Blue Angel or LEED still require bookkeeping and evidence of biomaterial content but do not carry the weight of legal compliance.
- Market Forces: Market forces will continue to grow as a driver of the use of biomaterials in industrial coatings. These can take the form of direct consumer demand for more sustainable house paints, or as in the case of industrial coatings, it may be come from businesses requiring that more sustainable product finishes be used in their manufacturing processes. This may be a bottom-up demand from customers or as part of a larger corporate sustainability initiative. No matter the reason, the growth of biomaterials in industrial coatings is sure to grow in the future.
Bio-based Materials for Paints and Coatings
View a wide range of bio-based ingredients available today and gain technical assistance through the technical datasheet of each product.