Rad-Cure Raw Materials and Equipment

By Christine Esposito | August 11, 2005

A look at the latest offerings from suppliers.

While rad-cure remains one of the bright spots for the coatings industry, its growth levels had slowed in recent years. Key end markets were plagued by the overall sluggish economy and the radiation cured market as a whole couldn't escape the downturn.

But if trade shows are any indication of how well a market is faring, there was good news this spring in Charlotte. RadTech's e|5 exposition attracted close to 2,600 attendees and more than 125 exhibitors-numbers the every-other-year show hadn't seen since 2000. And now RadTech is gearing up for another event in 2005 (see side bar on page 38).

Another good sign for the market: investment continues in new markets such as China. Borden Chemical has formed a joint venture with UVITech, a Chinese producer of UV-curable coatings, to manufacture and market UV-curable coatings and adhesives for fiber optics, digital media and other applications. More recently, DSM Desotech announced plans to build a new facility in China (see Fresh Paint, p. 10 in this issue).

Based on activity in the raw materials and equipment sides of the business, suppliers to the UV and EB coatings marketplace appear bullish about the future as well. Of course, some contend that the market has rebounded to 2000 growth levels, while others are more cautious about just how far into a recovery the industry is.

"We are seeing rebound in rad-cure," commented Jim Yosh, business director, North America, Tego. "I don't see that it is back to the levels where it was years ago, but we are predicting decent growth."

According to suppliers Coatings World spoke with, the UV and EB marketplace continues to be fueled by the environmental benefits and speed the technology delivers to end customers.

"Things continue to be driven by environmental concerns," added Yosh. "But we are always hearing about increased speeds and increased productivity. Customers want materials that cure faster."

New Developments From Industry Suppliers
Suppliers to the rad-cure marketplace have launched a number of new technologies and continue to invest in their own businesses to better serve the marketplace.

At RadTech, Sartomer launched four new monomers and 15 new oligomers for the UV/EB-cure market. The new technologies include CN307, a polybutadiene diacrylate oligomer that demonstrates excellent flexibility, water resistance and chemical resistance; CN2261, a polyester acrylate oligomer developed for UV curable wood coating applications where hardness and abrasion resistance are required; and SR833S, a low viscosity difunctional acrylate monomer (polymerized by free radicals) suited for a variety of UV/EB-cured applications where flexibility and adhesion are required. SR833S also demonstrates good film toughness and weathering characteristics, according to Sartomer.

In late 2003, Sherwin-Williams' chemical coatings division launched new water-reducible UV-curable coatings within its Ultra-Cure line of UV-curable stains, sealers and topcoats. The new chemistry offers very low VOCs, low toxicity and performance comparable to solvent-based UV cure coating systems, according to the company.

Surface Specialties UCB has a number of new products including Ucecoat waterborne UV resins and Raylok performance products. In addition, the company has also developed new materials for auto refinish and is readying the launch of new products from the Vancryl emulsion polymer product line within the next few months. These developments follow an announcement made in the fourth quarter last year by the company that it would build a new production unit for rad-cure monomers in St. Ghislain, Belgium. The new facility, which is expected to be opened in 2006, represents an investment of E25 million and will have an annual production capacity of 30,000 tons, according to the company.

In April, BASF launched into the North American market the Larolux coating curing system-which uses UV light under a carbon dioxide atmosphere to cure coatings placed on three-dimensional metal, plastic or wood objects-opening up the opportunity to cure three-dimensional parts that had been impossible to cure using traditional UV air curing techniques.

"This new technology provides manufacturers with important cost-cutting benefits that can improve their products as well as the efficiency of their operations," said Werner Peter, business director, BASF Corp. According to Peter, it can cut curing times for coated three-dimensional parts and reduce VOCs and energy costs. "It also reduces or eliminates many problems that part manufacturers face, including 'heat-effect' and coating viscosity issues that present formulating challenges," Peter added.

The Larolux system employs coatings made with BASF's UV curing agents and UV light in a curing oven that contains a carbon dioxide atmosphere. When the oxygen content in the gas surrounding the parts is low, the UV dose can be reduced to such an extent that simpler, less expensive lamps can be used, and simple reflectors can illuminate three-dimensional objects. UV equipment manufacturer Ultra Violet Systems, a division of UV Technology, has worked with BASF to build UV curing ovens that are equipped with low energy lamps designed to inert-cure using carbon dioxide, and Allied PhotoChemical and BASF teamed up to formulate coating systems specifically designed for the Larolux process.

Equipment suppliers are also making strides in technologies to improve successful curing of 3D parts.

EIT has added the UV 3DCure multi-dimensional measurement system that incorporates up to 32 UV sensors per system, allowing profiling of any 3D object. The system allows the user to place UV sensors on different areas of complex, irregular surfaces to determine the amount of UV energy impinging on those areas. Users can profile small and large parts-car fenders, wood furniture, composite assemblies and airplane canopies-by placing sensors at various locations, exposing the entire part to UV and viewing the collected data on a computer.

"There is a high interest in water-based UV cure technology throughout the industry," commented Mario Pschaidt, vice president-marketing and technology at Alberdingk Boley, Inc. in Greensboro, NC.

Along those lines, Alberdingk has developed a variety of water-based resins that offer very quick water release, are easy to formulate and give a great looking film on a variety of wood and plastic substrates with the resistance properties of conventional UV cure systems.

Alberdingk's LUX 440 offers outstanding chemical resistance, physical dry before cure, excellent surface hardness, scratch and abrasion resistance and quick water release, and it is easy to formulate from low gloss to high gloss. In addition, LUX 440, which is suitable for clear and pigmented coatings, offers very good adhesion on wood and plastic and has excellent compatibility with polyurethane dispersions and acrylic emulsions, according to company officials.

Tego is also addressing the performance properties of pigmented UV systems.

"Pigmented UV systems have always lagged behind clears in physical and chemical properties," said Yosh, who said that Tego is currently working through the U.S. TSCA regulatory process for Tego Disperse 680 UV and 681 UV, a pair of dispersants for pigmented UV systems.

In addition, Tego is also promoting Tego 2250, which provides good flow and good clarity in UV systems, and Rad 2650, which delivers increased slip and anti-blocking properties to UV formulations.

Tego's parent company, Degussa AG, has made some investments into its UV capabilities. Its Aerosil and silanes business unit in D�sseldorf has completed the expansion of its production capacities for Aerosil special oxides in Rheinfelden, Germany. The line includes functionalized Aerosil R 7200, which can be used to improve scratch resistance of UV-cured coatings systems.

The connection between coatings and finishing equipment is essential to successful implementation of the technology, and equipment suppliers such as Fusion UV, continue to address customers' needs for faster cure and the ability to ensure batch-to-batch consistency.

Users looking for higher degrees of conversion, higher speeds and better depth of cure can turn to Fusion UV's Light Hammer 10 (LH10), a high-power 250 mm UV curing system. Operating at 600W/inch, the LH10 features a microwave powered irradiator and a solid-state power supply. The microwave technology combines a small diameter, electrodeless bulb with an elliptical reflector to provide high peak of UV irradiance for high speed cure, according to the company.

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