Photopolymerization system positive-working

My colleagues and I developed a novel imaging system, which resulted in products for the prepress proofing industry that were successful for over 35 years. They were big earners because the research was done with an eye on establishing a strong patent position, and no effective competition came along. The photo-oxidants that were developed became enormously successful as photopolymerization initiators, which allowed DuPont to manufacture a series of novel products of importance to the printing and electronics industries. Now, some 40 years after this work was done, these biimidazole derivatives still appear to be initiators of choice and are found to play a role in current patents. 

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