Overprint varnishes

Cerium/Rare Earth. Cerium 2-ethyIhexanoate [56797-01-4] and rare-earth driers promote polymerization and through dry. Like iron they are active at elevated temperature and, since they do not contribute to film discoloration, are recommended for white bake finishes and overprint varnishes where color is critical. Rare earths also find use at the other end of the temperature spectmm in coatings dried at low temperature and high humidity. 

However, the results do not necessarily reflect the fastness to overlacquering in actual application, because overprint varnishes may contain other solvents as well. Besides, a series of additional factors such as the effect of plasticizers, uneven flow of the pigmented lacquer, etc., play a role in pigment performance. The fastness to overlacquering is therefore most realistically determined in actual application. 

Another process where electron beam equipment is widely used is curing of overprint varnishes (OPVs). OPV is applied over a printed surface to protect the ink layer and to improve the appearance of the product. The exceptionally high gloss of such finishing coatings and varnishes is achieved specifically by EB cure. ... 

Overprint varnishes with high gloss, reachvity, and solvent resistance... 

C. General Characteristics and End-uses Same as 530 overprint varnish (offset printing). 

Kamicryl 2089 [Kamsons]. TM for a water based overprint varnish hard nonfilm-forming liquid. 

Inks. Solid dimer polyamides occupy a dominant position as vehicles for flexographic inks. They are additionally used as clear overprint varnishes and in rotogravure inks. Polyamide-epoxy combinations, to be discussed later, are also useful as silk screening inks, particularly on difficult-to-wet surfaces such as molded polyethylene. 

CD480, 492. [Sartomer] Acrylates monomers for electronic applies, (dry film resists, solder masks), w<, metal, and vinyl flooring coatings, printing inks, overprint varnishes. 

Luhydran . [BASF AG] Water-dilutable binders for electrocoating finishes, baking finishes, wood and plastic coatings, anticcNTOsion paints, printing inks, overprint varnishes. 

Sequabond . [Sequa] Acrylic and aoylic colymer emulsions for water-based inks and overprint varnishes. 

Styrofan . [BASF AG] Styrene-based polymer d persions gloss binders for paper, paper coatings, overprint varnishes raw material for laminating adhesives binders for bonding fiber webs. 

AM 8, and AM 9 were evaluated in an overprint varnish formulation for high speed litho applications. The viscosities of the formulations were measured with a Brookfield RVT viscometer. Curing was done with an RPC UV processor with two 200 watt/inch medium pressure Hg vapor lamps or with a Fusion Systems processor with one 300 watt/inch H bulb. 

Viscosities of overprint varnish formulations containing AM or epoxy acrylate are shown in Table 3. Viscosities of the AM formulations are in the same range as that of the epoxy acrylate. 

Table 3. Overprint varnish formulations containing AM or epoxy acrylate...

Table 5. Cured film properties for the overprint varnish formulations...

Polyester acrylates are used in a wide range of applications from overprinting varnishes to lithographic (offset) inks. 

At the other end of the spectrum, pressure-sensitive adhesives, contact adhesives, aqueous varnishes, clear sealants and caulks, overprint varnishes for metal decorating and printing are essentially pigment free. Minor amounts of silica are used for gloss reduction in the case of varnishes. Carpet, construction and ceramic/brick adhesives may contain substantial amounts of filler, not only to reduce cost but also to provide shear strength. Gloss and semi-gloss latex enamels... 

Uses Additive in coatings, overprint varnishes, emulsions, slip resist, floor polishes, polymers, adhesives, inks dispersant for pigments/min-erals/glass-filled plastics adhesion promoter Regulatory DOT nonregulated SARA 311 nonreportable, 313 report-able (maleic anhydride) Canada DSL, EU, Australia, Korea listed... 

Chem. Descrip. Aromatic urethane acrylate Uses Urethane-acrylic in radiation-curable coatings, lithographic inks, overprint varnishes... 

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