Printing Plate Research Articles

A Laser-Imageable Thermo-Sensitive Film Based on Tertiary Amine Oxide-Containing Resin

A modified phenolic resin containing tertiary amine oxide was prepared via a two-step method. Epoxy phenolic resin, F-48, was reacted with dimethylamine to give the phenolic resin containing the tertiary amine group, which was then oxidized with hydrogen peroxide to obtain the target product. The tertiary amine oxide-containing resin could easily dissolve in water. However, it became water insoluble after heat treatment at a high temperature such as 160 °C. Thermal properties of the tertiary amine oxide resin were studied with DSC and TGA. A thermo-sensitive film comprising the prepared resin and an IR-dye was prepared and laser-induced thermal imaging was also conducted. This material might be used to develop new chemistry-free printing plates.

A novel photochemical machining process for magnesium aerospace and biomedical microengineering applications

Research was carried out to evaluate the feasibility of fabricating perforated (filigree) magnesium microcomponents with metal wire widths of the order of the metal thickness using a photochemical machining (PCM) process. Experimentally, it has been demonstrated for the first time that metal wire widths of 0.15 mm can be achieved within a 2D, 0.25 mm thick magnesium foil to fabricate microcomponents for use as micro air vehicle (MAV) wings or stents through a bespoke PCM process. This etching process differs significantly from the industrial etching process used currently to manufacture magnesium letterpress printing plates and embossing dies.

New aqueous base developable photoresist for lithographic printing plates applications

AbstractNegative photoresists are materials that become insoluble in developing solution when exposed to optical radiation. This work describes the production of simple negative‐working resists, demonstrating aqueous development, for potential printing plate applications. The copolymers comprised glycidyl methacrylate (GMA) and acrylic acid (AA) via free‐radical solution polymerization in methyl ethyl ketone as a solvent using azobisisobutyronitrile as initiator at 60°C. Characterization of the copolymers prepared was carried out via IR, 1H‐NMR, and thermal analysis techniques. The copolymers of GMA/AA were successfully prepared over a wide range of composition. It was found that the copolymer containing 15 mol % of AA unit in the feed was developed with NaOH on copper plate rather than zinc plate and crosslinked in the presence of photogenerated acid (PAG) caused by acid‐initiated ring‐opening polymerization of pendant epoxide groups. Exposure of the resist films to UV radiation at λmax = 365 nm results in the generation of acid, and the subsequent baking process at 80°C for 1 min promotes the diffusion of the PAG, which initiates the cationic crosslinking of the epoxide rings. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

High efficient plastic solar cells fabricated with a high-throughput gravure printing method

We report on polymer-based solar cells prepared by the high-throughput roll-to-roll gravure printing method. The engravings of the printing plate, along with process parameters like printing speed and ink properties, are studied to optimise the printability of the photoactive as well as the hole transport layer. For the hole transport layer, the focus is on testing different formulations to produce thorough wetting of the indium-tin-oxide (ITO) substrate. The challenge for the photoactive layer is to form a uniform layer with optimal nanomorphology in the poly-3-hexylthiophene (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend. This results in a power conversion efficiency of 2.8% under simulated AM1.5G solar illumination for a solar cell device with gravure-printed hole transport and a photoactive layer.

High-Efficiency Low-Cost Photovoltaic Modules Based on CIGS Thin Films from Solution Precursors

AbstractWe describe the production of photovoltaic modules with high-quality large-grain copper indium gallium selenide (CIGS) thin films obtained with the unique combination of low-cost ink-based precursors and a reactive transfer printing method. The proprietary metal-organic inks contain a variety of soluble Cu-, In- and Ga- multinary selenide materials; they are called metal-organic decomposition (MOD) precursors, as they are designed to decompose into the desired precursors. Reactive transfer is a two-stage process that produces CIGS through the chemical reaction between two separate precursor films, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are rapidly reacted together under pressure in the presence of heat. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. In a few minutes, the process produces high quality CIGS films, with large grains on the order of several microns, and preferred crystallographic orientation, as confirmed by compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% were achieved using this method. The atmospheric deposition processes include slot die extrusion coating, ultrasonic atomization spraying, pneumatic atomization spraying, inkjet printing, direct writing, and screen printing, and provide low capital equipment cost, low thermal budget, and high throughput.

導電性高分子を用いた再利用可能なアルミニウム製印刷板の試作

A printing plate for gravure printing consisting of five layers of aluminum alloy / anodic oxide film / nickel / polypyrrole / copper was fabricated by anodizing, electro-less plating, electroplating, and electro-polymerization. Nickel layers were first deposited on anodic oxide film-covered aluminum alloy by electro-less plating and electroplating. The polypyrrole layer was then deposited on the nickel layer by anodic polarization in a pyrrole monomer solution. Many copper fine particles were deposited on the polypyrrole-deposited specimen at the initial stage of electroplating in the CuSO4 / H2SO4 solution; then a continuous copper layer was obtained through longer cathodic polarization. The copper layer with polypyrrole was removed easily from the nickel layer by pulling with adhesive tape, which suggests that the structure is useful as a reusable aluminum printing plate by copper electroplating and electro-polymerization.

Nancy Drew and Friends: Girl Detectives

Nancy Drew and Friends:Girl Detectives Benjamin Lefebvre (bio) Nancy Drew and Her Sister Sleuths: Essays on the Fiction of Girl Detectives, edited by Michael G. Cornelius and Melanie E. Gregg. Jefferson, NC: McFarland & Company, 2008. Nancy Drew and Her Sister Sleuths is an excellent collection of essays that emerged out of a conference on "Nancy Drew and Girl Sleuths" held at the co-editors' home institution of Wilson College in Chambersburg, Pennsylvania, in February 2007. The bulk of the focus is on Nancy Drew, a literary character and pop culture phenomenon that has received a fair amount of scholarly attention throughout the last decade (see, for example, Nash; Rehak), as have her brother sleuths, the Hardy Boys (see Connelly; Greenwald). But the overall aims of the volume are to investigate the popularity and the commodity value of what Michael G. Cornelius terms in his introduction the "Moll Dick," a term that he locates in an early Trixie Belden book referring to the blending of typically male and typically female gender values that the girl sleuth embodies: courageous, logical, resourceful, and justice-seeking on one hand, and feminine, nurturing, glamorous, and self-effacing on the other. By amalgamating what Cornelius refers to as "the qualities perceived to be finest in both boys and girls" (3), the girl sleuth has not only proven to be a durable figure in US literature for young people across the twentieth century and into the twenty-first, but this literary "girl boy" is also continually reimagined across time as a product of the now. While the overall collection does not purport to solve the mystery of the Moll Dick as swiftly and definitively as many of the series books that it discusses, the individual chapters lay the groundwork for a vast array of ongoing conversations about the lures, pleasures, and challenges of girls' sleuth stories. James D. Keeline kicks things off with a discussion of a number of myths that have been perpetuated about Edward Stratemeyer and the cultural production of one of his most popular series, Nancy Drew Mystery Stories, first published by Grosset & Dunlap in 1930. Thanks to his careful sifting through the Stratemeyer Syndicate archives at the New York Public Library, Keeline clears up a number of misconceptions, beginning with the common claim that the Nancy Drew series was devised out of an attempt to match the sales of [End Page 267] the Hardy Boys series, begun in 1927, even though its sales were half of those of another Stratemeyer series, the Ted Scott Flying Series. As well, according to Keeline, the syndicate's decision to revise and sanitize the first thirty-four Nancy Drew titles was not done solely out of a motivation to remove racist stereotyping (which proved unexpectedly controversial, given the removal of most characters of color altogether). Rather, manufacturing costs related to the production and storage of printing plates made the rewriting and shortening of earlier texts a worthwhile endeavor, since it would cost as much to reset old books according to up-to-date methods. Subsequent chapters on the Nancy Drew books focus on a range of topics: Linda K. Karrell on Foucauldian notions of collaborative authorship; co-editor Melanie E. Gregg on French translations and cultural adaptation; Leona W. Fisher on xenophobia and white privilege, and Michael G. Cornelius on the ways in which science and technology repeatedly foil the otherwise unflappable girl sleuth, revealing a set of gendered interactions and hierarchies concerning skill, formal training, and the binary opposition between rationalism and superstition. Fortunately, the authors do not limit their discussion to the canon of fifty-six titles published in hardcover by Grosset & Dunlap between 1930 and 1979, but incorporate some of the hundreds of additional titles published by Simon & Schuster since 1979. Fisher, in particular, notes that the patterns of white privilege persist in the latest series, Nancy Drew: Girl Detective, launched in 2004. The second half of the book takes as its focus some of Nancy Drew's sister sleuths, none of whom (with the partial exception of Trixie Belden) has been able to replicate the popularity and enduring appeal of Nancy Drew. Readers who are familiar mainly with the Nancy Drew franchise...

Observations sur les sculpteurs de statuettes religieuses du Hunan

Occasionally, in a context in which information is sparse, exceptions arise. Since ancient times, Chinese woodworkers have, in certain circumstances, appended their signatures to the items they produced. This is, for example, true of engravers of printing plates who were sometimes obliged to account for their work, make claims for their artistic skill, etc. It is also true of sculptors of religious statues in Hunan, whose signatures implied a degree of "technical" competence not only in terms of woodworking but also of religious knowledge (consecration rituals, funeral rites, etc.). The inventory of these artisans in three collections of statuettes is remarkable for both its wealth and precision: all the names are accompanied by dates and places. However, a problem remains—how can this information be made to "speak" about ordinary people when traditional historical sources are obviously lacking. The article focuses on contemporary materials, which provide information about present-day practices and shed retrospective light on what such practices may have been in the past, before moving on to a comparative analysis of the data drawn from the statuettes and their certificates of consecration, ranging from the 16th to the 20th centuries. The "portraits" of the sculptors remain imprecise and the ancient secrets of the "profession" obscure—but how could it be otherwise for a practice reserved to initiates? However, the article does succeed in describing the role of the sculptors, a role as important as that of other "actors" presented in this volume, within the ambit of a local rural society in which religion is a central part of life and gives structure to the social network.

Fabrication and Application of TiO2‐Based Superhydrophilic–Superhydrophobic Patterns on Titanium Substrates for Offset Printing

A fabrication process for superhydrophilic-superhydrophilic patterns on titanium substrates prepared through a combination of an ink-jet technique and site-selective decomposition of a self-assembled monolayer (SAM) by a TiO(2) photocatalyst under UV irradiation is described. We demonstrate that the prepared titanium substrate is applicable as an offset printing plate with high resolution (133 and 150 lines per inch). Furthermore, the superhydrophilic-superhydrophobic patterns on the substrate can be deposited repeatedly after elimination of the patterns by photocatalytic decomposition of TiO(2) under UV irradiation. A second printed image with the renewed substrate showed no significant difference in image quality compared with the initial image.

Microscopic studies of the influence of main exposure time on parameters of flexographic printing plate produced by digital thermal method

The digital thermal technology of producing flexographic printing plates from photopolymer plates is one of the newest technologies. This technology allows to develop flexographic plates without the use of any solvent. The process of producing flexographic printing plates by the digital thermal method consists of several main stages: back exposure, laser exposure, main exposure, thermal development, post exposure, and light finishing. The studies carried out with the use of optical stereoscopic microscopy allowed to determine the effect of time of main exposure to ultraviolet radiation on the dot area, diameter, and edge factor of halftone dots reproduced on flexographic printing plate produced by the digital thermal method, as well as on the quality of reproducing the surface and on the profiles of free-standing printing microelements. The results of the microscopic studies performed have allowed to define the criteria of establishing optimum time of main exposure of photopolymer plates used in the digital thermal technology of producing flexographic printing plates. A precise definition of the criteria for determining the optimum time of main exposure will enable to reduce the time-consuming control tests and to eliminate errors in both the process of manufacturing flexographic printing plates and in the printing process carried out with the use of such plates.

Novel in-line method for patterned deposition of conductive structures

We report on a novel method for patterned deposition of conductive polymers, which is derived from and fully compatible with fast in-line printing methods. The method is aimed at improving resolution, homogeneity and edge sharpness of printed conductive structures for applications in the field of printed electronics. The surface energy of a foil substrate, which has been increased by means of corona treatment, was reduced in selected areas through contact with materials that have suitable surface properties and can be patterned at micrometer scale (i.e. printing plates). A conductive fluid was sprayed onto the chemically heterogeneous surface. The fluid accumulated at areas with higher surface energy. After the drying process, the conductive polymer structures were used as source/drain contacts for the preparation of OFETs.

Ultraviolet‐induced aging of flexographic printing plates studied by thermal and structural analysis methods

AbstractThe properties of photopolymer printing plates subjected to artificial aging processes were investigated with differential scanning calorimetry and microscopic analysis. The results showed that exposure to extended ultraviolet radiation type C in the prepress process caused changes both in the thermal properties and in the structure of the outermost surface layer. Long exposure to ultraviolet radiation type A in a weathering tester led to structural changes at a deeper level and a simultaneous increase in the glass‐transition temperatures of the polymeric material. Spectroscopic analysis showed that extensive oxidation occurred in the outermost surface layer. This study provides insight into important aging processes of the photopolymer printing plates. The knowledge can be used to predict the lifetime of printing plates and to understand the effects of their aging on print quality. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Switchable hydrophobic-hydrophilic layer obtained onto porous alumina by plasma-enhanced fluorination

Conventional lithographic printing processes using porous alumina for offset applications generally use “wet” routes. Recently “dry” processes have been developed which are based on a heat-induced hydrophilic/oleophilic conversion of one or more layers of the coating so that a stronger affinity towards ink or water fountain is created at the exposed areas with respect to the surface of the unexposed coating. Treatments involving rf plasma-enhanced fluorination (PEF) constitute exceptional tools for modifying the surface properties of materials. Many advantages of these techniques can be indeed outlined, when compared to more conventional methods: room-temperature reactions, chemical modifications limited to surface only without changing the bulk properties, possible non-equilibrium reactions. The influence of PEF treatments on porous alumina layer used in printing plates has been tested with various fluorinated gases (CF4, C3F8 and C4F8) and characterized by XPS. The hydrophobic properties of the fluorinated layer have been deduced from contact angle measurements. Using C4F8 rf-PEF treatment, the outmost surface of the hydrophilic alumina substrate used for lithographic printing is hydrophobized, or in other words, the hydrophilic substrate is converted into a support with hydrophobic properties. Once being hydrophobized, the surface layer may be rendered hydrophilic using a heat pulse, thus giving rise to switchable hydrophobic-hydrophilic properties of the material.

Molecular Mechanism of the Water Vapor Treatment of Thermal Printing Plates

Thermal printing plates based on novolak, a phenol-formaldehyde condensation polymer, are now used by some 80% of the printing industry worldwide. Until recently, the image discrimination of these plates; i.e., the difference in the dissolution rate between exposed and unexposed areas was only moderate. About three years ago it was discovered that treatment of the plates with water vapor substantially improves image discrimination. This treatment is now an important manufacturing step, but there is no generally accepted explanation of the water vapor phenomenon. We venture to offer such an explanation and are exploring its consequences for the performance of the thermal plates.

On correlation between fractal dimension and profilometric parameters in characterization of surface topographies

This study reports and discusses the results of investigation of correlation between fractal dimensions D EIS inferred from electrochemical impedance spectroscopy measurements and profilometric parameters obtained by contact (stylus) and non-contact (laser) profilometric methods. The research, conducted on two types of printing plates with different aluminium oxide surface topographies, revealed that there exists a good correlation between D EIS and certain profilometric parameters, although there are significant differences in values of roughness parameters inferred from stylus method in respect to these inferred from the non-contact measurements. The best correlation, regardless of the applied method or printing plate type, exists between D EIS and the average surface roughness parameter R a . Generally, better correlation between fractal dimension and profilometric parameters is observed for parameters inferred from contact measurements than for those obtained by non-contact (laser) methods. The correlations between fractal dimension D EIS, which is a very good descriptor of overall surface topography, and various profilometric parameters, provide significant information on the surface topography and an additional insight into processes responsible for its changes.

The Odyssey of a Polymer Chemist in Switzerland

A personal survey of some of the polymer-related work which I had the chance to carry out in Ciba-Geigy's Central Research and in the polymer departments of Ciba SC, Vantico and Huntsman is given, including a few short comments on the eventful history of the former Ciba-Geigy Central Research and Polymer Division. In the early 1970s, high-temperature-stable aromatic [polyamide – polyimide] block copolymers and the relatively easy processable bismaleimides as high-temperature thermoset materials were the dominant theme. Work on photocrosslinkable DMI polymers which ultimately led to the development of a non-silver graphic film and a presensitized negative offset printing plate was pursued at the Centre de Recherche Marly. In the field of epoxy resin chemistry, 'latent' hardeners, featuring a relatively long pot-life at room temperature and a short cure cycle at the processing temperature, were devised in the form of benzyl-sulfonium salts and imidazole-functionalized microgels. Ciba-Geigy's polymer division has pioneered the development of liquid, photoimageable soldermasks with it's Probimer® range of products. Here binderpolymers constitute the main components of the complex formulation recipes. High molecular weight polymers carrying acryloyl and carboxyl functional groups were synthesized for this purpose and have found commercial application in new soldermask generations.

Formation and Defining the Different Aluminium Oxide Microstructures in Alkaline Solutions

The formation of different aluminium oxide microstructures on the offset printing plate during the plate making process influences the plate’s ability to adsorb and repel fluids. Adsorbing and repelling of the fountain solution and ink during the offset printing process have major influence on the plate’s stability and print quality. The aim of this research was to define the micro structural changes in the aluminium oxide layer during the plate making process, their influence on the surface free energy of the oxide, as well as contact angles of the adsorbed fluids.

高感度光重合開始系の最近の進歩

A photopolymer material has been widely used in negative-type photosensitive composition (e.g. as a radical or an acid catalyzed polymerization). A large number of photo-initiator com-pounds for these compositions have been developed corresponding to many industrial demands such as coatings (overcoats, adhesives), graphic materials (printing plates, inks), electronic materi-als (printed circuit, micro-resist, color filter), and recording materials (holography). With recent development of light source especially for IR, Visible, and UV lasers, there is a growing interest to increase their photo-sensitivity. To perform much higher sensitivity, dye sensitizers are usually utilized in both radical and cationic photo-polymerization, and are elaborately designed in combi-nation of initiators. The dye sensitization is mainly classified into 1) electron transfer mechanism and 2) energy transfer mechanism. The dyes, therefore, are controlled and adjusted to their physi-cal properties such as wave length, redox potential, and excited energy level according to the mechanism. In this paper, the classification of these initiators/dye sensitizers and their character-istics are shortly described. Furthermore a few recent applications are introduced as an example of high sensitive material.

Printing Methods for Printed Electronics

Printing is certainly one of, if not the fastest, least expensive, and highest volume manufacturing technique. Its use for the deposition of functional materials offers enormous advantages for the preparation of devices over large areas, on virtually any substrate, and potentially inexpensively. Although printing processes have existed for thousands of years, it has only been relatively recently that the materials have become available for printing functional, particularly electronic devices.A wide variety of different printing processes can be used for printed electronics. Digital Fabrication of electronic devices can incorporate either high volume printing processes – those that use a physical master (printing plate or cylinder), archaically known as “analog” printing, or techniques that don't use a physical master (also known as “digital” printing processes). Impact as well as non-impact printing processes are important. For device fabrication, the printing process flow depends on many factors, some of which are dictated by material properties, others are determined by printing related factors such as resolution, registration, and economic considerations.This article will focus on the printing processes used for printed electronics, giving specific examples, as well as trends, challenges, needs, and future opportunities.

Three-Dimensional Ink Jet Prints–Impact of Infiltrants

Among various rapid prototyping methods, some are based on ink-jet printing process. 3D printing process discussed is based on conventional ink-jet technology, using powder material instead of two dimensional substrate and liquid binder as an ink. 3D prints obtained are quite brittle and porous, so usually they are finished by an infiltrant agent prior the final use. Epoxy resin, cyanoacrylate and polyurethane based agent are regularly used for this purpose. The impact of infiltrant type on the selected mechanical properties and surface appearance of three-dimensional ink-jet prints was the focus of the study. The type of infiltrant agent used greatly contributes to the discussed final properties of the prints. As a case study, the application of 3D printing in conventional printing technology was studied. 3D prints can be used as flexographic printing plate directly and as a negative matrix for conventional photopolymer flexographic printing plate production. For the matrix method, it is important that the applied infiltrant penetrates completely into the 3D print without any influence to its dimensions, as well as to have the optimum combination of mechanical and surface properties.