Radiation Curing of Coatings
Reviewed by: Anthony J. Berejka
co-founder and Past-President of RadTech International NorthAmerica

At the recent RadTech 2002 conference, two books published byASTM International (www.astm.org) made their debut:

Radiation Curing of Coatings by Dr. Joseph V. Koleske
ASTM Standards Related to Testing of Radiation-Cured Coatings

Both of these books should be in the libraries and collectionsof those interested in radiation curable materials.

Radiation Curing of Coatings is unlike many other booksin this field in that it is a coherent work of an experienced andastute author, Joe Koleske. Other tomes that have come out inrecent years on radiation curing and radiation applications arecompilations of diverse articles from numerous contributors. Assuch, these other works highlight some areas, neglect others andhave differing points of view, depending upon the contributors,being somewhat heterogeneous collections much like the RadTechconference proceedings themselves. In this easy-to-read 244 pagebook, Dr. Koleske blends his historical perspective on thedevelopment of various aspects of radiation curable coatingstechnology and in particular chemistry with sound fundamentals onbasic reactions not only involved in radiation curing andphotochemistry, but also used in the development of materials usedin this field.

Chemists new to this area as well as those experienced inradiation curables will find this book an invaluable resource ofpertinent information on structures, reactions, and key propertiesthat are given in concise tables. The experienced chemist will alsofind the extensive references at the end of each chapter to beexhaustive lists of patents and articles tracing the development ofthis technology from its inception to the present. One finds inalmost every chapter a bit of history on the development ofradiation curing. For example, in discussing "Free-RadicalPhotoinitiators and Initiation Mechanism" (Chapter 3 ), Dr. Koleskerelates the story of how slow rates of acrylate polymerization forcementing bomber turrets during World War II was an impediment tocommercial development. In "Free Radical Initiated PolymerizationSystems" Chapter 5 ), Bill Burlant's saga of the 1950's indemonstrating the instantaneous cure of electron beam cured systemsto Henry Ford and his senior staff is relayed. These vignettesought to be read by the non-chemists in corporate managements toillustrate the arduous task and time-span of development forinnovative technologies such as radiation curing.

Throughout Radiation Curing of Coatings there is anexcellent balance between statements of fundamentals, as in thederivation of energy from light sources as found in "RadiationCuring" (Chapter 1 ) and the practical aspects involved inimplementing this technology. Free radical and cationic initiationand chemistry are well covered (Chapters 3, 4, 5 and 6 ) as well asa summary of currently available equipment (Chapter 2 ). Dual curesystems are also dealt with including UV powdered coatings (Chapter8 ). The diversity of options in "Dual-Cure Mechanisms" (Chapter 9)represents an under-exploited area of technology. The formulatorwill find the specific chapter dealing with additives (Chapter 11)to be most useful in that this is an area not often treated. To thechagrin of some smaller raw material suppliers, these variouschapters dealing with materials include reference to specificgrades made by specific major materials suppliers.

One market use, "Adhesives" (Chapter 10), is given somededicated attention and includes a section on release coatings.However, many other markets for radiation curable coatings,including inks, are grouped together in "End Uses" (Chapter 13) insummary fashion. In keeping with the format of this book ingeneral, some historical perspective is given to some of thesemarket areas. "Safety and Health Considerations" (Chapter 12) isalso only touched upon with reference being made to consult theRadTech web site. Finally, the "Glossary of Terms" developed by theRadTech UV Measurements Focus Group is included at the end of thebook.

In general, Radiation Curing of Coatings is a solid technicalwork well suited for those involved in or interested in becominginvolved in the radiation curing of low molecular weight materials,like inks, coatings and adhesives. It goes into considerably moredepth, especially in chemistry, than RadTech's UV/EB CuringPrimer( 1991 ) and is more current. Those in academia mightconsider this book to be a useful resource around which to build acoherent course on radiation curing in that there is still lackinga unifying text in this area.

ASTM Standards Related to Testing of Radiation-CuredCoatings is a compilation of 105 ASTM Test Methods, Practicesand Guides related to the radiation curing area, including thosedeveloped for electron beam technology. These are well indexed byareas of interest in the front of the book as well as having thecustomary ASTM format of indexing at the end. This supplantsRadTech's Radiation Curing Test Methods ( 1988 ) publishedunder license from ASTM with its 62 Methods, Practices and Guides,many of which have since been up-dated and revised. The crossreferences and indexes in this new compilation adequately replacethe explanatory text RadTech had developed for its 1988 book.Missing, however, are the conversion tables which can be found inany basic physics or chemistry handbook.

Of keen interest to the contemporary user is that this newcompilation from ASTM is also available on CD-ROM. The CD has anauto-launch feature which brings up the compilation onto a computerscreen immediately after inserting it into a CD drive. On the disk,there is both a "Table of Contents" of all of the "Standards andRelated Materials Contained in this Volume" and a "TopicalContents" listing. Of significant benefit is the built-in searchcapability. Thus, one can do key word searches for ASTM documentspertaining to a specific area of interest. The print or CD versionsare available at the same cost.

About the Author/Editor: A brief biographical sketch ofDr. Koleske is on the back outside cover of Radiation Curing ofCoatings noting his long industrial career, mainly with UnionCarbide, his numerous publications and patents. In RadTechInternational North America's formative days, Joe was often aparticipating lecturer on chemistry at seminars RadTech had thensponsored.

About ASTM International: Both Radiation Curing ofCoatings and the ASTM Standards Related to Testing ofRadiation-Cured Coatings have been published under the auspicesof ASTM Committee D01 on Paint and Related Coatings, Materials, andApplications. This committee deals with many of the areas ofinterest to RadTech members, such as inks and coatings. RadTechmembers are invited to join ASTM and this committee. There areplenty of issues germane to the radiation curing industry that thiscommittee deals with. For information on ASTM and D01 membership,visit the ASTM International web site at: www.astm.org or contactTim Brooke, the ASTM Staff Manager for D01, at 610-832-9729 ortbrooke@astm.org.

Tony Berejka is a co-founder and Past-President of RadTechInternational North America. He is a member of ASTM D01 and D14 onAdhesives and has been a member of ASTM International for over 30years.

Radiation curing technology can increase production, save money,improve working conditions, and decrease pollution. Manual 45, theonly practical handbook of its kind, focuses on this growingtechnology and is specifically directed at those who are in thefield of radiation curing of coatings, adhesives, inks, andsealants.

The manual's straightforward style makes it easily understoodand allows readers to go directly from the book to their specificwork area of radiation-curing technology. In general, the bookrelies on written explanations rather than numerous figures andtables. Because it impartially and objectively deals with thesetopics, the reader can decide which particular chemistry topursue.

Industrial applications include: overprint varnishes, printingand graphic arts, automotive, plastics, electrical, electronic,optical, UV powders, and wood finishing.