PHOTOPOLYMERISATION AND PHOTOIMAGING SCIENCE AND TECHNOLOGY

PHOTOPOLYMERISATION AND PHOTOIMAGING SCIENCE AND TECHNOLOGY

PHOTOPOL YMERISATION AND PHOTOIMAGING SCIENCE AND TECHNOLOGY Edited by NORMAN S. ALLEN, BSc, PhD, DSc Chemistry Department, Faculty of Science and Engineering, Manchester Polytechnic, Manchester, UK ELSEVIER APPLIED SCIENCE LONDON and NEW YORK

ELSEVIER SCIENCE PUBLISHERS LTD Crown House, Linton Road, Barking, Essex IG 11 8IU, England Sole distributor in the USA and Canada ELSEVIER SCIENCE PUBLISHING CO., INC. 655 Avenue of the Americas, New York, NY 10010, USA WITH 27 TABLES AND 78 ILLUSTRATIONS 1989 ELSEVIER SCIENCE PUBLISHERS LTD Softcover reprint of the hardcover 1 st edition 1989 British Library Cataloguing in Publication Data Photopolymerisation and photoimaging science and technology 1. Photopolymerisation I. Allen, Norman S. 547'.28 ISBN-13: 978-94-010-6999-1 001: 10.1007/978-94-009-1127-7 e-isbn-13: 978-94-009-1127-7 Library of Congress Cataloging.in.Publication Data Photopolymerisation and photoimaging science and technology / edited by Norman S. Allen. p. cm. Bibliography: p. Includes index. 1. Polymerization. 2. Photochemistry. 3. Photolithography. I. Allen, Norman S. QD381.9.P56P48 1989 547'. 28--dc20 No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Special regulations for readers in the USA This publication has been registered with the Copyright Clearance Centre Inc. (Ccq, Salem, Massachusetts. Information can be obtained from the CCC about conditions under which photocopies of parts of this publication may be made in the USA. All other copyright questions, including photocopying outside the USA, should be referred to the publisher. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher.

PREFACE During the past decade the fields of photopolymerisation and photoimaging science have grown from subjects of esoteric research specialities into major industrial developments and are now fields of central importance in polymer science and technology. Free-radical addition polymerisation, cationic polymerisation, photolithography, photocrosslinking, photografting, photochromic imaging and topochemical polymerisation all continue to gain important new grounds in industry. Much new research continues in these areas and today has given rise to many new applications in such fields as microelectronics, e.g. in resists, barrier coatings, encapsulants and printing board technologies. Without the use of photo resists it would not be possible to develop modern electronic and computer industries. This book is meant to be a comprehensive and up-to-date text in the science and technology of all the above subjects with each chapter being written by a very prominent specialist or specialists working in the particular area concerned. The chapters have a strong international flavour and cover a very wide range of topics. The first, by Dr Hageman at Akzo Chemie in the Netherlands, deals with the most fundamental subject of them all, namely photo initiated addition free-radical polymerisation. Here emphasis is on the mechanistic behaviour of both established and new carbonyl-containing systems. Cationic photopolymerisation has also established itself as a field of some importance and this is reviewed expertly by Dr Pappas from the North Dakota State University in the USA. Again the main emphasis here is on the mechanistic features of the individual types of photoinitiators. Chapter 3 has a more industrial flavour and deals with the chemistry of photolithography and photocrosslinking materials and processes; it is written by Drs Turner and Daly of the Eastman Kodak Company in the USA. Chapter 4 covers a somewhat different slant to photopolymerisation, that of photografting monomers onto polymer systems in order to improve a particular property requirement. This is dealt with effectively by Professor Bellobono from the University of Milan in Italy. Photochromic processes are only now just growing in v

vi PREFACE importance and here the science and chemistry of the systems involved are reviewed in Chapter 5 by Dr Jacobson from the Central Polytechnic in London. The complex nature of solid-state photopolymerisation is dealt with in Chapter 6 by a well-known authority in the field, Professor Hasegawa, who is at the University of Tokyo, Japan. In Chapter 7 the excited-state properties of photo initiators is seen through the use of lasers; this subject is well covered by Professor Fouassier at the University in Mulhouse, France, who is a noted expert in this area. Finally, Chapter 8 covers a subject which has hitherto often been omitted from books in this field. The post-cured stability of radiation-cured systems is now of some importance, especially in applications where long-term durability is required to both heat and light. Little has been published on this subject to date and this chapter details the extensive efforts of one of my Ph.D. students, Dr White, into this problem with emphasis on thermal and photooxidative stability and photo yellowing of radiation-curable resins. This book should therefore appeal to all polymer scientists, physicists and technologists working in the fields of radiation curing and photoimaging science and technology as well as those with little knowledge of the subjects who wish to learn and develop some expertise. NORMAN S. ALLEN

CONTENTS Preface..... List of Contributors v ix 1 Photoinitiators and Photoinitiation Mechanisms of Free- Radical Polymerisation Processes..... H. J. HAGEMAN 2 Photoinitiated Cationic Polymerization S. PETER PAPPAS 3 The Chemistry of Photo resists...... S. RICHARD TURNER and ROBERT C. DALY 4 Photografting Processes onto Polymers.. IGNAZIO RENATO BELLOBONO and ELENA SELU 5 Photochromic Imaging R. E. JACOBSON 55 75 115 149 6 Four-Center Type Photopolymerization of Diolefin Crystals 187 MASAKI HASEGAWA 7 Excited-State Properties of Photoinitiators: Lasers and their Applications...................... 209 J. P. FOUASSIER 8 Post-Cured Stability of Radiation-Cured Resins...... 249 N. J. WHITE, N. S. ALLEN, P. J. ROBINSON and R. CLANCY Index.......................... 305 VII

LIST OF CONTRIBUTORS N. S. ALLEN Department of Chemistry, Faculty of Science and Engineering, Manchester Polytechnic, Manchester M1 5GD, UK IGNAZIO RENATO BELLOBONO Universita degli Studi di Milano, 20133 Milano-Via C. Golgi 19, Italy ROBERT C. DALY Electronics Research Laboratories, Eastman Kodak Company, Rochester, NY 14650, USA J. P. FOUASSIER Laboratoire de Photochimie Generale, Unite Associee au CNRS no 431, Ecole Nationale Superieure de Chimie, 3 rue A. Werner, 68093 Mulhouse Cedex, France H. J. HAGEMAN Akzo Research, Corporate Research Department, Postbus 60, 6800 AB, Arnhem, The Netherlands MASAKI HASEGAWA Department of Synthetic Chemistry, Faculty of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan ix

x LIST OF CONTRIBUTORS R. E. JACOBSON School of Communication, Polytechnic of Central London, 18/22 Riding House Street, London W1P 7PP, UK s. PETER PAPPAS Polymers and Coatings Department, North Dakota State University, Fargo, ND 58105, USA P. J. ROBINSON Department of Chemistry, Faculty of Science and Engineering, Manchester Polytechnic, Manchester M1 5GD, UK ELENA SELLI Universita degli Studi di Milano, 20133 Milano-Via C. Golgi 19, Italy R. CLANCY Harcros Chemicals Limited, Silk Street, Eccles, Manchester M30 OBH, UK S. RICHARD TURNER Corporate Research Laboratories, Rochester, NY 14650, USA Eastman Kodak Company, N. J. WHITE Department of Chemistry, Faculty of Science and Engineering, Manchester Polytechnic, Manchester M1 5GD, UK. Present address: Banbury Laboratories, Alcan International Limited, Southam Road, Banbury OX16 7SP, Oxfordshire, UK