Printing Ink Industry

Iron blue pigments are used in the manufacture of single- and multiple-use carbon papers and blue copying papers, both for toning the carbon black and as blue pigments in their own right [3.172]. 

While the visual judgment of black is influenced by the individual ability of the observer to distinguish small color differences in deep black, it is possible, with the help of photometric measurements, to graphically interpret objective evaluations by means of physical data [3.186]. 

The basic requirements for the successful use of iron blue as a toning agent in offset printing inks are resistance to damping or fountain solutions and good dis- 

The combined dispersion of pigments is only practical with colorants of similar dispersibility. Toning agents with a considerably higher resistance to dispersion than carbon black are therefore delivered by the manufacturer in the form of a predispersed paste or must be ground separately by the user. 

In the following section, the coloristic effects of these iron blue pigments are described, as obtained in toning experiments involving a LCF-type carbon black, in comparison with Pigment Blue 15 3 and Pigment Blue 61 (Figs. 3.24-3.26). 

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As solvents, the amyl alcohols are intermediate between hydrocarbon and the more water-miscible lower alcohol and ketone solvents. Eor example, they are good solvents and diluents for lacquers, hydrolytic fluids, dispersing agents in textile printing inks, industrial cleaning compounds, natural oils such as linseed and castor, synthetic resins such as alkyds, phenoHcs, urea —formaldehyde maleics, and adipates, and naturally occurring gums, such as shellac, paraffin waxes, rosin, and manila. In solvent mixtures they dissolve cellulose acetate, nitrocellulose, and ceUulosic ethers. 

The highly unsaturated DCPD resins are generally modified to improve their performance in adhesives and printing ink industry. Three modifications are generally produced. 

Newton s law states that for a liquid under shear, the shear stress T is proportional to the shear rate. In this sense, most of the unpigmented vehicles used in the paint and printing ink industries are considered ideal or Newtonian liquids. The ratio of the shear stress t to the shear rate D is thus a constant t), dependent only on temperature and pressure. This is not true for specialized gel varnishes and thixotropic systems, which are designed to have special rheological properties. 

Organic pigments are used to color a variety of media. It is useful to distinguish between three primary fields of application the coatings and paints industry, the printing inks industry, and the plastics and fibers industry. Besides, organic pigments are used for special purposes, for instance in office materials and in the mass coloration of paper. 

Certain areas of pigment application in the printing ink industry challenge the performance of a pigment more severely than others. To be useful in inks for food cans, for instance, the inside coatings must be capable of being sterilized with steam without degradation. For bank notes, currency, and cheques, special security properties are needed. 

P.Y.97 is used in a variety of fields. Even in pastel shades, it is used in industrial finishes while its full shades lend color to automobile refinishes. In emulsion paints, both its medium and full shades are suited to exterior application. The printing ink industry uses P.Y.97 in high grade printing products, especially where excellent fastness is required, such as in stable posters, etc. It lends itself without difficulty to all printing techniques. However, lack of fastness to monostyrene and acetone and therefore a certain tendency to bleed in these media precludes its application in deco printing inks, i.e., for decorative laminates. 

The printing ink industry, currently the most important area of application for diarylide yellow pigments, first introduced these products around 1938 in the USA. 

Although P.Y.14 is less important than P.Y.12 and 13, the packaging and textiles printing ink industries use it in large volume. P.Y.14 is somewhat greener than... 

P.Y.83 can be used for all printing techniques and purposes. The printing ink industry often prefers highly transparent, mostly resinated types. Printing such... 

P.Y.114 is primarily supplied to the printing ink industry, where it is used especially for packaging inks. The pigment is utilized to produce prints at reasonable cost, especially where exceptional fastness, as provided by P.Y.83, is a minor consideration. Prints made from P.Y.114 are not entirely resistant to a number of organic solvents, including the standard DIN 16 524 solvent mixture, paraffin, and butter but P.Y.114 prints are soap, alkali, and acid resistant. The fact that the pigment does not withstand a temperature of 140°C and is not stable to sterilization excludes P.Y.114 from use in metal deco printing. 

Pigment Red 8 affords clean, bluish shades of red. It is primarily used in the printing ink industry. P.R.8 exhibits high tinctorial strength and produces brilliant prints. Commercially available types with specific surface areas between about 50 and 60 m2/g afford transparent prints. P.R.8 is used in prints which require no particular solvent resistance. However, the pigment tolerates solvents much better than the yellower P.R.7 in this respect, P.R.8 matches the yellower, but more light-fast P.R.5. The prints are fast to soap but not entirely stable to butter and paraffin. P.R.8 is sensitive to clear lacquers coatings and to sterilization. It tolerates exposure to 140°C for 30 minutes. 

The printing ink industry uses P.R.146 for letterpress and offset inks and also in packaging gravure and flexo printing inks. The pigment lends itself to a variety of special applications it is used, for instance, to print bank notes and securities. A certain tendency to migrate, however, precludes its use in print on plasticized PVC films. 

The printing ink industry uses P.Y.120 primarily for decorative printing inks on laminated melamine and polyester resin sheets. In terms of lightfastness, 8% gravure prints in 20 and 40 pm cells on such plates correspond to step 8 on the Blue Scale. Plate-out is not observed. P.Y.120 is insoluble in monostyrene and acetone (Sec. 1.8.1.2). 

P.Y.154 is a useful pigment for the printing ink industry wherever high light-fastness is required. Letterpress proof prints up to 1/25 SD equal step 6-7 on the Blue Scale for lightfastness, which is at least 11/2 to 2 steps above that of similarly colored diarylide yellow pigments or representatives of the monoazo yellow pig-... 

P.R.175 has stimulated interest throughout the printing ink industry wherever high lightfastness, excellent solvent fastness, fastness to sterilization, and very high heat stability (up to 220°C) are a requirement. 

The printing ink industry uses P.Br.25 for all printing methods. The prints show excellent lightfastness. 1/1 to 1/25 SD letterpress proof prints, for instance, equal step 7 to step 6-7 on the Blue Scale. Prints made from P.Br.25 are fast to the DIN 16 524 standard solvent mixture, to paraffin, butter, soap, and acid, but they are not entirely fast to alkali. The products are fast to clear lacquer coatings and may safely be sterilized. The temperature stability is up to 240°C for 10 minutes or 220°C for up to 30 minutes, which makes P.Br.25 a suitable candidate for metal deco printing inks. It is also frequently applied in printing inks for PVC. 

Like other representatives of its class, P.Y.95 has only limited impact on the printing ink industry. It is only used in special-purpose printing inks for high grade... 

The printing ink industry applies P.Y.110 in all types of printing, provided the pigment satisfies the demands. The prints are resistant to many organic solvents, including the DIN 165224/1 standardized solvent mixture. Prints made from P.Y.l 10 are fast to clear lacquer coatings, sterilization, and are very heat stable. 1/1 to 1/25 SD letterpress proof prints equal step 7 on the Blue Scale for lightfastness. 

The printing ink industry utilizes P.Y.139 to color high grade printing products. 1/3 SD letterpress proof prints equal step 7 on the Blue Scale for lightfastness. 

The printing ink industry employs P.O.61 mainly in products which are to be printed on PVC films. 

The printing inks industry uses P.B.15 3 especially as a blue component on different color scales for three and four color printing. The pigment corresponds to the CIE12-66 standard shade of cyan on the European Color Scale for offset and letterpress prints (Sec. 1.8.1.1). 

The printing ink industry utilizes P.Gr.7 particularly for packaging printing inks. In this area, however, green shades are frequently also produced by combining the less expensive (3-Copper Phthalocyanine Blue with suitable organic yellow pigments. 

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