Printing inks conductive

Letterpress. This is the oldest printing process stiU in use. It continues to be replaced by newer printing processes. Printing is conducted from a raised image area of the printing plate. Inks in the printing process are transferred directly from a raised area to a substrate. The printing plates contain a thick layer of photopolymer (often a mixture with polymer such as poly(vinyl alcohol) deposited over a plastic or aluminum base. 

Inks for continuous ink-jet printers typically comprise dyes dissolved in water or solvent having salts added to make the ink conductive for electrostatic charging. Whenever waterproof printing is required, low boiling solvent inks ate used. For printers that ate used in office environments, water is used as the ink solvent. Using water-based inks, humectants may be added to inhibit drying of ink in the sump and surfactants ate added to wet the printing surface. 

Carbon blacks are principally made by the chemical decomposition of natural gas or oil. Two classes predominate the furnace blacks (95% of black usage) which are active, and thermal blacks (5% of usage) which are inactive. There are a substantial number of blacks for special applications such as electrically conducting and printing ink blacks. The latter are of too fine a particle size for rubber use. The nomenclature used for carbon blacks includes the ASTM designation and the industry type as illustrated in the next table. 

In the near future, we expect to see adoption and adaptation of inkjet technology to rapidly growing markets such as photovoltaics, OLEDs, and thin film transistors. In general, the development of flexible printed electronics for a wide range of applications is expected to take advantage of the value proposition of inkjet printing of conductive inks. 

Carbon black [1333-86-4] is virtually pure elemental carbon (diamond and graphite are other forms of nearly pure carbon) in the form of near-spherical colloidal particles that are produced by incomplete combustion or thermal decomposition of gaseous or Uquid hydrocarbons. Its physical appearance is that of a black, finely divided pellet or powder, the latter sometimes small enough to be invisible to the naked eye. Its use in tires, mbber and plastic products, printing inks and coatings is related to the properties of specific surface area, particle size and structure, conductivity and color. 

Structure The structure of the pigment black is an important parameter for the production of printing inks. A number of quaUty attributes depend on the structure dispersion properties, viscosity, flow properties, color density, gloss, mb resistance, and conductivity ... 

Another important commercial compound is zinc oxide, which is used as a catalyst in the rubber industry and to make pigment for products such as plastics, cosmetics, wallpaper, and printing inks. This compound also conducts electricity and is used to make photocopying machines. 

In the materials science area, dendrimers have been used for adhesive tie coats to glass, metal, carbon, or polymer surfaces, additives for polymer resins and composites, printing inks, surfactants, cross-linking agents, electrically conductive nano devices,flow regulators, processing aids, and chemical... 

To ensure continuous conductivity along a printed line, conducting ink drops must be printed in an overlapping fashion. Often, creating a single line or film with acceptable conductivity requires more than one layer of ink. The additional layers can be printed either before or after the previous layers have dried. 

High exposmes remained common in paint and printing ink industry still in 1970 s for example, most solvent measurements conducted in these industries in Finland exceeded the present OELs. Water-based paints are today clearly most common in construction painting. Alkyd-based construction paints with white spirit (Stoddard solvent, mineral spirit or solvent naphtha) as a solvent are, however, still produced. Solvent-based paints have remained most common in industrial painting, even though the solventless powder paints are also produced in large quantities. 

An exhaustive review of research studies and activities in the inkjet printing of conductive materials has been presented (5). The inkjet printing process and the various types of conductive inks have been detailed. The various factors that affect the quality of printed matter have been described. These include the printing parameters, materials and the pretreatment of the substrate to be printed. 

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