This paper reviews synthesis and property of UV-curing materials based on hyperbranched polymers, calixarenes, and noria. The synthesis of UV-curing hyperbranched polymers was examined by the polyaddition of bisepoxide as A₂- type monomer, triscarboxilic acid as B₃-type monomer, and methacrylic acid as C-type monomer, i.e., A₂＋B₃＋C method afforded corresponding hyperbranched polyesters with methacryloyl groups at the ends. The synthesized hyperbranched polyester had good solubility, good film-forming property, and high UV-curing reactivity. Furthermore, the obtained cured films of hyperbranched polymers had higher cross-linking densities compared to those of linear polymer. Next, calixarene derivatives and noria derivatives with pendant radical polymerizable groups and cationic polymerizable groups were synthesized, and their physical properties and UV-curing reactivity were examined. As the result, synthesized calixarene derivatives and noria derivatives had also good solubility and good film-forming property. Especially, their UV-curing reactivity were superior to those of linear polymers and hyperbranched polymers.

View full abstract

Over thirty years has passed since the ultra violet (UV) curing technologies became applicable to a printing ink. The domestic demand of the UV curable ink in 2012 is estimated approximately 11,000 tons, and the use of them has spread in varieties of printing areas including paper packaging, business forms, self-adhesive labels, and plastics, where the characteristics of the UV curable ink can be advantageous. In recent years, commercial printing jobs (newspaper insert, prints circulars, catalogs, etc.) which are ordinarily printed with conventional inks, started to adapt UV printing processes due to the high productivity of the system. There are many types of UV curable ink for each application and printing process. The UV curable inks are designed to meet the quality requirements by utilizing the varieties of raw materials and optimizing their combinations. The choice of resin materials in the ink formula is especially important as it decides the performance of the products. Adding, this paper introduces the latest topics of the UV curable printing industry such as 1) Environmentally friendly UV ink and 2) High reactivity UV ink.

View full abstract

The features and properties of photosensitive film such as sensitivity or resolution were described in this review. As for sensitivity, the photoinitiation mechanism and method to obtain high sensitivity on Hexaaryl biimidazole which is mainly used for photosensitive film were introduced as well as the influence of matrix. The optical contribution such as absorbance or scattering and the swelling contribution of pattern in development were discussed for resolution. Moreover, the methods to improve mechanical strength of film were introduced.

View full abstract

Photosensitive polyimides have been utilized as buffer-coat layer between IC chip and encapsulating resin. However, conventional photosensitive polyimides have disadvantages such as necessity of high temperature post-curing after pattern formation due to their use of polyimide precursors, poly(amic acid)s, as polymer components. We have developed a novel mechanism, reaction development patterning (RDP), to give photosensitivity to polyimides and other engineering plastics containing carboxylic-acid-derivative bonds in their main chains. Pattern formation by RDP is based on selective change in solubility of engineering plastics at photo-irradiated (or unirradiated) areas by nucleophilic acyl substitution between carboxylic-acid derivatives in a polymer chain and nucleophiles in a developer during development process. Thus, RDPbased photosensitive polyimides can be obtained from polyimides themselves, and pattern formation from polycarbonates and polyesters is also achieved by applying RDP to these polymers. Here, pattern-forming mechanism of positive- and negative-tone RDPs and their scope of application are described.

View full abstract

Photoresists are essential for making fine patterns in LSI production. Photoresists are divided into two types, i.e., positive and negative types. The positive type photoresists are the polymers which become soluble in the developer after exposure. On the other hand, the negative type photoresists are the polymers which become insoluble in the developer after exposure. Non-chemically amplified and chemically amplified types were developed for the negative- and positive-type photoresists. The chemically amplified photoresists are highly sensitive compared to the non-chemically amplified ones. The chemically amplified photoresists are used for KrF (248 nm) and ArF (193 nm) lithography in LSI industries. The photoresists for EUV (13.5nm) lithography are also developed based on the chemically amplified concept. This review paper is focused on the negative type photoresists using the network formation.

View full abstract

Focusing of reactive intermediates into ultra-small spatial area provides fundamental concepts for precise visualization of nano-materials and/or miniaturization of materials by ionizing radiations. In contrast, homogeneous interaction of ionizing radiation in the bulk matters is also the most important principle in radiation chemistry, leading to the highly quantitative analysis of chemical reactions induced by radiation chemical processes in relation to those in the photochemical dynamics. “Focusing of reactive intermediates within a charged particle track” is the nature of chemical reactions induced by high energy charged particle, which is in the cross-over range of concepts of the recent nano-miniaturization / visualization techniques and well-sophisticated radiation chemical processes. In the present paper, we demonstrated intra-track reactions induced by high energy particles as a versatile tool for one-dimensional nano-material fabrication by combining the high permeability of the particle in the materials with non-homogeneous distribution of the intermediates along the trajectories.

View full abstract