Forest on a hill

Ecological, sustainable building

Mar 01, 2019 Read time: approx. MinutesMinute

Based on renewables

Ecological, sustainable building is one of the major trends in the construction industry. With the market launch of VINNECO®, WACKER has introduced a line of binder products based partly on renewable raw materials. The new VAE dispersions are produced via two manufacturing processes – one using bio-acetic acid and the other potato starch.

From private home builders to architects on large-scale projects – for more and more property developers, the use of environmentally friendly construction materials plays an important role. Recognizing this market potential, the industry has been looking for alternatives to fossil resources for some time now. “The trend toward biobased products has caught up with interior paints too,” says Dr. Lada Bemert, a senior technical service manager at WACKER POLYMERS. Market figures back up that claim: in 2017, biobased paints and coatings generated US$1.14 billion in sales in Europe and the US according to a study entitled “Growth Opportunities for Bio-Based Chemicals and Materials in Europe and North America, 2017” conducted by the Frost & Sullivan consulting company. And that upward trend is likely to continue: given its average annual growth rate of 4.3%, market researchers expect the market for biobased paints and coatings to grow to a volume of US$1.52 billion by 2024.

“Our customers are increasingly looking for alternatives to fossil feedstocks as well,” Bemert notes. “We’ve updated our processes accordingly and our use of renewable raw materials is taking dispersion manufacturing in a new direction.” There are two methods for producing binders based on renewable resources, and the Munich chemical group will market these binders under the VINNECO® product line. WACKER will be unveiling five products at the 2019 European Coatings Show in Nuremberg.

Paint roller

When used in wall paints, WACKER’s polymer dispersions ensure that pigments, fillers and additives are held together and that the paint adheres to the wall to optimum and durable effect.

The use of wood as a resource in the first production method proved to be a good choice: “Our polymers are based on acetic acid sourced from the wood-processing industry,” says Dr. Martin Schierhorn, a chemist and marketing manager at WACKER POLYMERS. “The compound is formed as a byproduct of wood-industry processes such as preparing fibrous material for paper manufacturing. You don’t have to chop down a tree, in other words, to make acetic acid from it.” The wood is sourced from PEFCTM-certified forests located within a 400-km radius of WACKER’s Burghausen site. PEFC, which stands for Programme for the Endorsement of Forest Certification Schemes, is a certification system for sustainable forest management. PEFC standards govern practices such as reforestation, securing habitats and biodiversity, and protecting soil, water and the climate.

Hiding power test – application of paint

At WACKER’s applications laboratory, tests are performed on the hiding power of paint modified with the new polymer/starch hybrid binder.

Hiding power test – spreading over a substrate

To test its hiding power, the paint is spread evenly over a black substrate. The contrast ratio is then measured.

Bio-acetic acid

WACKER uses ethylene and the bio-acetic acid obtained in this way to produce vinyl acetate monomer, which – again using ethylene – is copolymerized to form vinyl acetate-ethylene (VAE). The binders are polymer dispersions that, in the example of wall paint, hold pigments, fillers and additives together and ensure optimum, lasting adhesion of the paint to the wall. No aspects of either the binders or the wall paints suggest whether the VAE they contain was produced from conventional or from biobased acetic acid. The compound always exhibits the same chemical and physical behavior, regardless of whether it was derived from fossil-based or renewable raw materials.

“In studies, we were able to demonstrate that acetic acid from renewable raw materials meets our quality requirements in every respect. Its purity is very high and its water content is low.”

Dr. Lada Bemert, Senior Technical Service Manager, WACKER POLYMERS

“That’s why bio-acetic acid represents a real alternative to its counterpart based on fossil feedstocks like natural gas or crude oil. By blending it in with traditional acetic acid, we can directly couple it to our existing VAE production line,” the chemist points out.

This allows paint manufacturers to keep their existing formulations without having to adjust them in any way for their plasters or wall paints. “But that also means that not even our customers can tell whether the binders we deliver are derived from fossil-based or biobased acetic acid,” Bemert adds.

Biomass balance method

To verify the biobased component and demonstrate this to its customers, WACKER uses the biomass balance method. This approach allows the company to calculate how much of a VAE dispersion was produced from renewable raw materials. The method, which WACKER is applying for the first time in vinyl acetate-ethylene production, has been certified by the TÜV SÜD international technical inspectorate in accordance with the global CMS 71 standard. As Bemert explains, “When customers order from the new VINNECO® product line, they can be sure that the required amount of bio-acetic acid has been fed into the integrated production system.” As verification, the customer receives a TÜV certificate attesting to the use of the renewable raw material.

For the customer, this means that sustainable versions of the products in the VINNAPAS® family, which remains a well-known, classic brand, are now available under the new VINNECO® brand. At the 2019 European Coatings Show, WACKER will be introducing four specific products suitable for use as binders in plasters and paints. For the moment, only a relatively small percentage of WACKER’s global output of VAE dispersions is based on renewable resources. The biomass balance approach, however, will allow the company to adjust those amounts going forward. In addition to its new binders for interior paints and plasters, WACKER offers biomass-balance versions of other product lines, such as vinyl acetate homopolymer dispersions and solid resins based on vinyl acetate.

Measuring the contrast ratio

Measuring the contrast ratio

Starch-based production

WACKER takes a much different approach for the second binder production method, cooperating with Dynaplak, a Dutch company that manufactures biobased raw materials. The material in this case is starch, which exhibits the properties of a binder when emulsified. This natural polymer is a side-stream product of potato processing. Experts at Dynaplak use this starch, which would otherwise be lost, and modify it with an innovative technology to improve its performance. “Even though natural starch has been known as a binder for millennia, it isn’t really the best for modern industrial applications. We take the enhanced form from Dynaplak and combine it with our vinyl acetate-ethylene polymers to form a new hybrid binder,” Bemert explains. The modified biopolymer accounts for 30% of the new product. This reduction in the amount of traditional VAE derived from fossil-based raw materials yields a lower carbon footprint in the resulting product.

Direct comparison of wall paint

When directly compared with conventional wall paint, the good hiding power of paint modified with VINNECO® CT 7030 is confirmed.

The result is a high-performance binder that WACKER will be marketing under the name VINNECO® CT 7030. As Schierhorn says, “Our new, hybrid product makes us one of the first companies on the market to combine vinyl acetate-ethylene polymers with starch for industrial applications. We’ve maximized the proportion of starch as much as we can. When it comes to rheological properties, wet-scrub resistance, dispersibility and hiding power, VINNECO® CT 7030 can hold its own with traditional products made from fossil feedstocks. Because this is a new product with its own property profile, however, paint manufacturers may need to update their formulations under certain circumstances. The advantage is that the starch polymer allows them to directly utilize biomass in the finished product. Schierhorn went on to point out that the biological component of VINNECO® CT 7030 could for example be verified by means of the carbon-dating method, which is used for verifying the age of fossils, among other applications. That this new product will not be an isolated case is likewise certain: “Demand for alternatives based on renewable raw materials is growing, especially for interior paints,” Schierhorn says. “That’s why we’re working with Dynaplak to develop a wide selection of hybrid binders.”

“Demand for alternatives based on renewable raw materials is growing, especially for interior paints.”

Dr. Martin Schierhorn

Prospects for the new VINNECO® product line are good, in other words – and they confirm WACKER’s commitment to sustainability. “The VINNECO® brand is an additional product line for us, and we will be introducing specific products both at the European Coatings Show as well as throughout 2019,” says Schierhorn. “This has been an initial, important step toward using renewable raw materials in the production of our binders. And we will continue to look into more methods for reducing fossil feedstocks.”

The biomass balance method

If raw materials from renewable and traditional – usually fossil-based – resources are used as starting materials within the same integrated production system, the biomass balance approach can be used for mathematically assigning the portion of renewable raw materials to individual sales products. Fossil feedstocks are then mathematically assigned to the production of all other sales products. The approach is comparable to the green electricity certification system used in Germany.

The international TÜV SÜD technical inspectorate has certified WACKER’s mass balance method for verifying renewable raw materials in production. This gives WACKER a recognized method for tracking its use of renewable resources throughout the entire production process, up to the finished product. To qualify, suppliers of renewables must use a sustainable manufacturing process for the raw materials that WACKER purchases, and all of the required starting materials must be obtained from sustainable sources as well. WACKER must also undergo an annual TÜV inspection to verify that the appropriate amount of renewable raw materials is always added during the production of declared products.

Graphic biomass balance method
Section of a tree trunk

An overview of the five VINNECO® products

VINNECO® products based on the biomass balance method can be identified by the abbreviation MB in their names. These are each available in two grades, in which either 60% or 100% of the fossil feedstocks have been replaced with bio-acetic acid.

VINNECO® EP 3360 (60MB)
Proportion of fossil feedstock replaced: 60%
Properties: aqueous polymer dispersion composed of vinyl acetate and ethylene, with a solids content of ~60%
Application areas: dispersion-based interior wall paints and plasters

VINNECO® EP 3360 (100MB)
Proportion of fossil feedstock replaced: 100%
Properties: aqueous polymer dispersion composed of vinyl acetate and ethylene, with a solids content of ~60%
Application areas: dispersion-based interior wall paints and plasters

VINNECO® EF 3777 (60MB)
Proportion of fossil feedstock replaced: 60%
Properties: aqueous polymer dispersion composed of vinyl acetate and ethylene, with a solids content of ~56%
Application areas: dispersion-based interior wall paints and plasters

VINNECO® EF 3777 (100MB)
Proportion of fossil feedstock replaced: 100%
Properties: aqueous polymer dispersion composed of vinyl acetate and ethylene, with a solids content of ~56%
Application areas: dispersion-based interior wall paints and plasters

VINNECO® products based on starch for paint applications can be identified by the abbreviation CT in their names.

VINNECO® CT 7030
Properties: aqueous polymer dispersion composed of vinyl acetate, ethylene and modified starch, with a solids content of ~47%
Application areas: interior wall paints

Contact

For more information on this topic, please contact:

Mrs. Dr. Lada Bemert
Senior Technical Service Manager
WACKER POLYMERS
+49 8677 83-2566
lada.bemert@wacker.com