Metal deco printing

Pigment performance also includes fastness to transparent lacquer coatings ( silver lacquer ), that is, fastness to transparent enamels which are applied to metal deco prints to give them rub and scratch fastness. 

C. This is true not only for their use in plastics, such as polypropylene and polystyrene, but also for applications such as metal deco prints, which are baked at temperatures above 200°C, or powder coatings, which are processed above 200°C. 

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. 

The fact that P.Y.127 recrystallizes only very slightly facilitates its dispersion in modern agitated ball mills. The pigment is easy to disperse and its heat stability parallels that of P.Y.13. Its fastness to clear lacquer coatings and to sterilization are excellent, which is why the pigment is suitable for metal deco printing. 

Transparent P.O.34 is somewhat sensitive to heat and generally only withstands temperatures up to 100 to 140°C. Higher sterilization or metal deco printing temperatures may produce a color shift towards a redder orange. 

At typical pigment area concentrations, i.e., standard depths of shade in the range between 1/1 and 1/25 SD, the lightfastness equals step 4 or 3 on the Blue Scale, respectively. Application in metal deco printing is not feasible, which is also true for other pigments within the same class. 

Almost all Naphthol AS pigments, with a few exceptions, are excluded from metal deco printing. However, a number are used in large volume by the textile printing industry. Poor migration and heat resistance make most members of this class inapplicable to plastics. 

Commercially available P.O.46 types are usually quite transparent. They are employed primarily in packaging printing inks, also in offset and metal deco printing. Publication gravure inks, plastics, especially PVC, LDPE, and elastomers, as well as general industrial paints are suitable media for pigment application. P.O.46 is less solvent resistant than P.R.53 1, but it is faster to alkali and acid. In terms of lightfastness, P.O.46 performs poorly 1/3 and 1/25 SD prints equal only step 1 on the Blue Scale. 

P.R.66, a barium salt, is sold only in the USA. The pigment is also available as an aluminum oxide hydrate precipitate. Its shade is considered a brilliant medium red, which is somewhat yellower than that of the chemically related P.R.67. Commercial types of P.R.66 are very transparent. The pigment is highly sensitive to acid, alkali, and soap. Its fastness to organic solvents is poor, its fastness to overcoating as well. P.R.66 exhibits limited lightfastness. Its main application is in metal deco printing. 

P.R.67, a barium salt, is also available in the form of an aluminum oxide hydrate precipitate. Its shade is bluer compared to the chemically related P.R.66, it is referred to as a bright bluish red. Commercial types are transparent and tinctorially strong. P.R.67 is used especially in metal deco printing. The prints do not tolerate acid, alkali, or soap. They show only limited fastness to organic solvents and to... 

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. 

P.R.221 is not recommended for use in polyolefins, since it also causes considerable distortion. It has, however, gained recognition as a pigment for high grade printing inks, especially for metal deco printing. 

Nonstabilized a-Copper Phthalocyanine Blue is utilized in the printing industry, to a certain extent in oil-based binder systems, such as offset printing inks for packaging and metal deco printing. Under standard conditions, P.B.15 is stable to a variety of organic solvents, such as alcohols, esters, ketones, aliphatic hydrocar-... 

Incorporated in printing inks, phase-stabilized a-Copper Phthalocyanine Blue, like nonstabilized types, is too reddish to be employed as a process color for three and four color printing. It is used, however, to a considerable extent in all types of printing inks for special and packaging purposes. The prints are stable to common organic solvents and exhibit perfect fastness properties in special application (Sec. 1.6.2.3). Metal deco prints withstand up to 200°C for 10 minutes or 170 to 180°C for 30 minutes. They may safely be sterilized. 

The prints exhibit excellent application properties. They are, for instance, entirely fast to organic solvents, soap, alkali, and acids. They are also fast to sterilization. Metal deco prints demonstrate very good heat stability. The products withstand exposure to 200°C for 10 minutes or to 180°C for 30 minutes. Although not quite as fast to heat as halogenated types of Copper Phthalocyanine Green, P.B.15 3 is thus somewhat more heat stable than stabilized a-Copper Phthalocyanine Blue. 

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