The Team UV race car. The car was developed to showcase UV technology. It came in "kit" form, which allowed for a custom-coated car without

having to take the car apart and repaint the pieces.

Speed - something for which both Indianapolis with the "Indy 500" and RadTech International with "Curing at the Speed of Light" are well known. Using radiation as a means of carrying out a curing process is expected to be very fast, and appropriately this year there was a racecar on the exhibit floor whose finish was radiation cured.

RadTech 2002 took place in Indianapolis from April 28-May 1. Attendance at the meeting was very high considering the times; consequently, the meeting and exhibits were a huge success. This year about 2,500 people attended the conference and show. This was a small decrease from the record-setting crowd that attended RadTech 2000, which was held in Baltimore, and where about 2,800 people had been in attendance. The decrease of about 10% was minor in comparison to attendance at many other meetings, and the small decrease attests to the strong interest in radiation-curable coatings, inks, adhesives, and sealants.

There was a broad menu of interesting topics to choose from during the three-day meeting plus a day of pre-conference sessions. With concurrent sessions coupled with a large exhibit featuring equipment, chemicals, allied products, and insurance, it was impossible to take in everything during the four days. The pre-conference session was comprised of two all-day short courses that dealt with photopolymerization and polymer chemistry for radiation professionals. Included in this day of study was a two-hour introduction to UV/EB seminar.

The formal conference was opened with two informative speakers. The first topic, by Dr. Llewelyn King of The King Publishing Group, dealt with significant technological advances and how they will affect future life styles. The other topic, by Dr. Godwin Berner of Ciba Specialty Chemicals Inc., was concerned with the radiation-curing industry and the outlook for new directions and technology applications.

The concurrent technical sessions were comprised of organic chemistry - cationic and free radical intermediates as well as photoinitiators; inorganic chemistry - nanocomposites; analytical chemistry - surface tension, emissions, light absorption, and ultraviolet radiation measurement; physical chemistry - cure kinetics, process control technology; new chemistry - novel photoinitiators and intermediates for cationic and free radical systems; curing equipment - electron beam and ultraviolet radiation sources; international market overviews - China, Europe, North America; and last, a diverse poster session of 16 boards that dealt with many topics. Within the technical conference program, there were more than 100 speakers. Technical session attendance was high. Session rooms were spacious and there was ample seating in those sessions I attended. There were 1,117 pages in the bound, soft-cover Technical Conference Proceedings.

Intermeshed with the technical sessions was an end-user conference. This conference was composed of either half-day or whole-day sessions that dealt with applications for radiation curing technology. The general session topics were applications for adhesives, the automotive industry, electron beam technology, graphic arts, ultraviolet radiation-cured powder coatings, and wood coatings. An especially interesting portion of the graphic arts presentations was concerned with the conversion of presses for coating, flexographic printing, and lithographic printing from conventional technology to ultraviolet radiation and electron beam technology. The manuscripts for each of the end-user sessions were published separately from the technical conference proceedings and were available at the entrance to the particular sessions. For example, the automotive session had 97 pages of information, the graphic arts session had 53 pages of information, and so on.

There was also a half-day special session presented by the Canadian Focus Group that dealt with why one should use ultraviolet radiation and electron beam curing systems. The goal of this session was to promote the benefits of radiation curing, and this session gave a good understanding of the complete process required to gain the most from this technology. The topics discussed were radiation measurement, equipment, economics, chemistry, applications, and health and safety. Included was a presentation that was concerned with the history and pioneers of ultraviolet radiation curing.

Although it is not practical to even attempt discussing all of the topics presented at the meeting, a few that stood out are worth briefly mentioning. Radiation curing is a line-of-sight technology. Radiation does not bend around corners, and since curing depends on radiation interaction with chemicals in the formulation, it is necessary to develop technology to ensure intimate contact between ingredients and radiation. For flat surfaces, this is a simple matter. However, if three-dimensional objects are being coated, it is necessary to develop special technology. For some time, methods of moving the three-dimensional part in the "view" of the radiation source by rotation or other means have been employed. At this show, movable or reciprocating ultraviolet radiation sources were demonstrated. Thus, a part could pass steadily through the radiation area in a fixed configuration and the sources would move to ensure that the object was entirely cured. Combinations of reciprocating sources plus part rotation or other movement could also be used.

The high viscosity of acrylated epoxides used in free radical curing has been a limiting factor in the amount of these useful products that could be incorporated into a given formulation. To facilitate the handling of these oligomeric materials, they are often dissolved in other acrylates and marketed as solutions of moderate viscosity. At one press conference, a company described a new aromatic acrylated epoxide based on bisphenol A that was monomer free. In neat form, it had a room temperature viscosity of about 14,000 mPa_s, which is on a par or lower than that of many of the diluted acrylated epoxide solutions. Thus, the new oligomer will give formulators more formulating latitude and increase the epoxide character of the final coating. Another way of circumventing the problem of acrylate-oligomer high viscosity is to disperse such oligomers into water and this was described for urethane acrylates in certain presentations.

In the new chemistry area, photoinitiators and their technology appeared to be the main topic. Both cationic and free radical photoinitiators were described. A favorite topic was low odor and low migration photoinitiators for the graphic arts area. The studies included mechanisms, experimental products, and available products that were TSCA listed as well as products for which PMNs were in progress. One manuscript described photocurable systems that would cure without added photoinitiator. Such systems might be based on, for example, ethyl acetoacetate/diacrylate oligomers. Initiation and cure take place through the inherent photo activity of the oligomer rather than through an added photoinitiator. This particular presentation entitled "Novel Resins That Cure Without Added Photoinitiator - Chemistry" by Dr. Matthew Sheridan of Ashland Specialty Chemical Co. won the Best Technical Paper Award.

In the new product debut session, there were interesting topics that dealt with a new dosimeter, an ultraviolet radiation cured thermal transfer printing process, new electron beam technology, infrared curing of adhesives, several new acrylates, very low gloss coatings, a new cycloaliphatic epoxy monomer, and others. The topics were intriguing and potentially useful additions to the technology base. There was one difficulty with this particular session - out of 16 presentations, only six manuscripts were submitted and available to attendees. It was the only session with such a discrepancy, since almost all manuscripts for the other sessions were available.

The exhibit hall had over 125 booths/exhibitors. Business at the various booths seemed very heavy. People were not just chatting; they were earnestly looking for information. Very seldom did one merely walk up to a booth and receive immediate attention - it was necessary to wait your turn even though the booths were well staffed. From the activity, it did not appear there was any downturn in the radiation-curing interest.

The end-user product showcase was a bit sparse, but there were a number of products on exhibit. A Ford Truck was on display, and four placards surrounding it described the long, impressive list of UV-cured components in or on the truck (see sidebar).

The exhibit items also included conformal coatings and solder masks for printed circuit assemblies, pipe and floor coatings, pet-food packages, baseball bats, lottery tickets, and wood and glass coatings. In addition to end-use items found in the exhibit hall, many booths had displays or photographs of other end-use products such as UV-cured powder coatings on wood, clear coats on various substrates, and so on.

Meridian Automotive Systems received two awards - Best of Show and People's Choice - for their pickup truck body-box outer, which featured a UV-thermal sealer. Ford Motor Co. received the President's Technology Advancement Award for its work in both the science and the implementation of radiation curing technology in the automotive industry. Ford's efforts in the radiation curing field date back to the mid- to late 1950s or well before the technology had become popular in industry.

The Hartford Financial Services Group Inc. and RadTech have combined forces to provide printers and users of safe, emerging technology a way to save money on their insurance costs. Loss control experts at The Hartford will work with printers to point out savings that can be achieved by employing radiation-curing systems. Indications are that a number of end users are taking advantage of the cost savings. Details can be obtained at www.thehartford.com.

Overall, RadTech 2002 was a success. Again Gary Cohen, executive director of RadTech International N.A., and Ann Goyer of Goyer Management International deserve kudos for their efforts in presenting a well-planned and organized conference and exhibit. Attendees appeared to enjoy themselves and the valuable knowledge they acquired.

Charlotte, NC, will be the site of the next major RadTech International North America meeting. RadTech 2004 will be held in the Charlotte Convention Center on May 2-5, 2004. For more information and exhibit space, contact Goyer Management at 513/624.9988; e-mail cherry@one.net.

UV-Cured Components Found on Ford Truck and Other Vehicles

Headlamp assembly parts
Abrasion resistant metallization topcoat
Abrasion resistant topcoat on exterior plastic lens
Electrical connector potting compound
Glass and plastic lens/reflector adhesive
Metallization prime coat
Electrical and electronic applications
Coil terminators
Component marking inks
Conductive inks for rear window defroster
Motor balancing compounds
Potting compounds
Printed circuit assembly coatings-solder masks and conformal coatings
Screen-printed membrane switches
Sensor switch encapsulants
Strain relief for electrical connectors
Tacking adhesives
Windshield-wiper motor sealing adhesives

Miscellaneous

Abrasion resistant topcoat for metallized plastics, side body moldings, and acrylic tail lamp assemblies
Adhesives for bonding mirrors to their supports
Gasketing for door handles and other gasketing uses
Interior clear coatings with excellent mar resistance and low gloss
License plate coatings with excellent scratch and chemical resistance
Metallization primer for plastic "chromed" parts
Release coatings for simulated leather interior
Products-dashboards and doors
Sealers and topcoats for customized van and RV wood components
UV-cured coatings for wheel covers
UV-cured sealant for airbag explosive cartridges
Windshield repair products
Wood grain printing and topcoats for interior laminates