Ink System Research Articles

Polymer Emulsion-Based Ink Jet Colorant and Ink

The ink jet printing system is becoming popular in the market. There are two varieties of ink in the conventional ink jet ink system. One is water-soluble dye based ink and the other is pigmented ink. Dye-based ink has clear color and high reliability, however it is suffering from insufficiency of waterfastness and lightfastness. Pigmented ink has advantages in waterfast and lightfast, but it has limitation on ink stability, clear color and rub resistance. Therefore, new inks have been required to overcome these problems.We have developed new emulsion colorant in order to solve these problems. The colorant is water based polymer emulsion containing water insoluble dye or pigment. When using polymer emulsion containig water insoluble dye, prints show clear color, waterfastness, and rub resistance properties. And when using polymer emulsion containing pigment, prints show waterfastness, lightfastness, and rub resistance properties. Emulsion-based ink would be a technological breakthrough to improve the durability of aqueous ink jet system.

Pigmented Latex System for Ink Jet Printing on Textile

The objective of work is to explore the application of small particle size polymer latex systems in ink jet printing on textile substrates. Pigments are incorporated in the latex to give colored inks. The routine of selecting microlatex and nanolatex polymer resins is set up. Particle sizes, surface tension, conductivity and viscosity of selected latices are measured and adjusted to meet the requirements of the printer. The Imaje Jaime 1000 S4 continuous ink jet (CIJ) printer is used to test these formulations. Cotton, silk and polyester/cotton are used as substrates. The printed substrates are evaluated in four aspects, colorfastness, hand, comfort and microstructure. The type of resin and ink formulation are optimized and used to develop a pigmented CMYK ink system.

Pollution-preventing lithographic inks

A pollution-preventing lithographic ink system works conventionally at a pH less than 7, but becomes its own emulsifying agent at high pH. Accordingly, it can be washed off lithographic printing presses with aqueous base. The emulsification kinetics of the ink have been experimentally studied as mass transfer coefficients under the conditions of low shear. Correlations for this mass transfer suggest that washing is controlled by diffusion of components within the ink. The results point toward a strategy for achieving other pollution-preventing technologies.

Micro-glassy carbon inks for thick-film electrodes

A description follows concerning the formulation of a model conductive ink system and the physico-chemical characterisation of thick films based on spherical glassy carbon micro-particles with low molecular mass polystyrene binding polymer. The study considers the effects of the carbon and polymer ( C P ) mass ratio from 0.43 to 9.0 on the film surface morphology, electrical resistance and electrochemical properties. The surface structure of micro-glassy carbon films was examined by electron microscopy showing that surfaces have high polystyrene content when the C P ratio falls below 2.3. Electrical resistances corresponding to dielectric materials are found for thick films prepared with inks containing 30% m/m or less carbon in the formulation. It was necessary to introduce the micro-spherical carbon to proportions beyond 60% m/m in order to reduce film resistances to less than 1 kΩ. The electrochemical properties of micro-glassy carbon films correlate with C P ink values, where a transition is observed from insulator characteristics to random array microelectrode and ultimately a micro-porous macroelectrode.

Microstructural Evolution of Copper Thick Films Observed by Environmental Scanning Electron Microscopy

A generic copper thick film ink system was formulated to be representative of the inks currently used in industry. The microstructural evolution of two of the copper‐based inks based on the generic composition was investigated using an environmental scanning electron microscope (ESEM) equipped with a hot stage. The first ink, consisting of copper and organic constituents (binder and solvent), oxidized heavily during firing while the second ink, consisting of copper, glass, and organic constituents, oxidized only slightly. The sequence of events observed in firing the ink comprised of copper, glass, and organics is as follows: The burnout process reached completion by about 320°C. Copper oxidation was observed to occur between 500° and 600°C in nitrogen. The glass was observed to soften over the same temperature range. By 700°C, the glass had softened and coated the copper particles. Prior to glass softening, oxidation occurred regardless of the presence of the glass. However, once the glass had softened, copper oxidation was retarded. Cu2O was found to be sufficiently soluble in the glass to allow it to be removed from the surfaces of the copper particles. Thus, the presence of glass facilitated the formation of conductive paths by two mechanisms. It inhibited oxidation and it dissolved the oxide that formed. Both processes allowed effective sintering.

The In-K (Indium-Potassium) system

The In-K (Indium-Potassium) system

Anodised Aluminium as an Alternative Substrate for High Power Hybrid Microelectronics

An investigation to evaluate the suitability of anodised aluminium as a substrate material has shown that the relatively high coefficient of thermal expansion of the aluminium caused the brittle cermet resistors to craze giving rise to unstable resistance values whereas PTF resistors appeared to suffer no ill effects. The work was implemented in conjunction with selection of low temperature thick film conductor and resistor inks to achieve the optimum combination of anodised aluminium substrate and ink system. These inks were then printed and fired on anodised aluminium, aluminium nitride and alumina substrates, and the physical and electrical properties of the inks and substrates compared. A combination of modest success, employing polymer resistors and cermet conductors, produced viable circuits with resistors of reasonable stability. A low power hybrid device, with surface mounted components, was employed to further validate the substrate/ink combinations in ongoing tests.

Migration of plasticizers from printing inks into foods.

It has been demonstrated that on storage of a tightly wound reel of polypropylene packaging film, specially printed for experimental purposes, transfer can occur of components from the ink on the outer surface of the film on to the inner food contact surface. For dicyclohexyl phthalate this transfer amounted to 6% of the total amount of plasticizer available in the printing ink system. It was subsequently shown for confectionery and snack food products wrapped in commercially printed polypropylene films that plasticizers only present in the printing ink migrated into the foods. The migration of plasticizer increased with storage time of the wrapped product; for dibutyl phthalate, for example, levels increased from 0.2 to 6.7 mg/kg over the period from 0 to 180 days storage of a chocolate-coated confectionery product. A small retail survey (47 samples) of confectionery, snack products and biscuits wrapped in printed polypropylene film showed the presence of one or more plasticizers at levels from 0.02 to 14.1 mg/kg for dibutyl phthalate, from less than 0.01 to 18.6 mg/kg for dicyclohexyl phthalate and from less than 0.01 to 1.8 mg/kg for di(2-ethylhexyl) phthalate. In all cases there was a good correlation between the plasticizers found in the printing ink from the film and those in the food. Wide variations were found, however, in the amounts and types of plasticizers used in printed packaging of the same brand of retail food product purchased from different regions of the country.

Liquid Ink Jet Printing with MOD Inks for Hybrid Microcircuits

Application of the computer-controlled impulse ink jet with liquid metallo-organic decomposition (MOD) inks is demonstrated to be feasible in printing hybrid microcircuits. The advantages of ink jet printing over conventional screen printing are discussed. The hardware and software of the ink jet printing system have been developed. The MOD ink system suitable for the ink jet has been studied. Printing experiments with the ink jet have been conducted during the research. A theoretical model has been derived relating the ink jet flow rate to the primary spray control parameters. The ink jet system with silver neodecanoate MOD ink has been applied to metallize the grid pattern of silicon solar cells.

Desmin-positive stellate cells associated with angiogenesis in a tumour and non-tumour system

The angiogenesis induced after implantation of fragments of the Walker 256 carcinoma was compared with the angiogenesis following implantation of different amounts of Indian ink. Morphologically and chronologically the tumour system showed no difference from the Indian ink system, provided sufficient amounts of ink were implanted. Both systems were characterized by significant macrophage infiltration. The vascular development, which was clearly concentrated in a dense rim around the tumour, remained present when the tumour enlarged, suggesting an acquisition of vasculature by the tumour through vessel incorporation and not vessel ingrowth. Initially, scattered desmin-positive cells, in contact or encircled by collagen IV, were found in the developing angiogenic rim. Later many desmin-positive cells were found around vessels and could be identified by electron microscopy as pericytes. They exhibited close local contacts with endothelial cells. After incorporation of the peritumour vascular rim into the tumour the number of pericytes decreased and their shape became flattened and elongated.

Resistance tests for inks

Essentially, a printing ink is nomore than a means of transferring a colour pigment onto a substrate. Having got it there quickly and efficiently — not always the easiest of tasks — the ink system must ensure that it remainthere under whatever conditions the end‐use requirements of the print demands. Sometimes these demands can be very stringent, and have necssitated a range of tests for resistance properties to be established by inkmakers, many of which have applications that are independent of the printing process.

Fire Resistant Films for Aircraft Applications

Alternative sandwich-panel decorative films were investigated as replace ments for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, selected toxic gas emis sion, flame spread, and suitability as a printing surface for the decorative acrylic ink system. Several of the candidate films tested were flame-modified polyvinyl fluoride, polyvinylidene fluoride, polyimide, polyamide, polysulfone, polyphenyl- sulfone, polyethersulfone, polybenzimidazole, polycarbonate, polyparabanic acid, polyphosphazene, polyetheretherketone, and polyester.

A User Made Thick Film System

This paper describes the state of the art in the development of a polymer based printed circuit board (PCB) compatible resistor ink system. The subject is treated from the standpoint of the manufacturer who, up to now, supplied himself with PCB circuitry.

Theoretical analysis of liquid immersion development in electrophotography

Liquid ink development depends upon the electrophoretic migration of charged toner particles towards a latent image, which is a pattern of surface charge on a dielectric. The electric field under which this occurs has two fundamental components—a driving field due to the latent image and an internal field which arises because of the space charge within the ink layer. A general analytic expression is obtained for the spatial frequency components of the electric field in terms of the frequency components of the charge distributions. The kinetics of the development process is then described by assuming two noninteracting species of charged particles within the ink and obtaining a solution for the motion of these particles. The problem is solved numerically for the case of a solid-area latent image and for a periodic image. The analysis is sufficiently general so that previous results in electrophoretic development emerge as special cases, which hold within certain limitations. Guidelines are provided with regard to the importance of the space-charge effect in a real liquid ink system.

An Ink Jet Facsimile Recorder

A facsimile recorder developed at Teletype Corporation utilizes a squirting ink jet as the printing device. The recorder produces copy having 200 lines per inch resolution on ordinary paper at the rate of 50 pages per hour. The design features a disposable ink system which can be replaced by an operator. The technique used for generating gray tones is readily adaptable to color printing.