Ultraviolet lacquers

Adhesion Loss of Ultraviolet-Cured Lacquer on Nickel-Plated Steel Sheets... 

UVC Lacquer and Test. A white epoxy-acrylate lacquer was applied on all nickel plated sheets with different pretreatments to a thickness of 16 ym and was cured by irradiation with four 10-kW ultraviolet lamps for about 1.2 sec. 

This product is an ultraviolet light absorber for use in polystyrene, unsaturated polyesters, coatings, varnishes, lacquers, and coatings based on epoxy or phenolic alkyds. It is also used in pressure sensitive adhesives, polymethylacrylate (fdm or sheeting), thermoplastic rubbers, polyisoprene latex and alcohol based cosmetics. 

The acrylic polymer which offers the best all-round properties for a metalcoating lacquer exposed to the weather is the hardest acrylic polymer, polymethyl methacrylate (molecular weight 80000-150000). It is hard, clear, scarcely coloured, very little affected by ultraviolet light, insoluble in commercial petrols and resistant to acids and alkalis. Marked deviations from the homopolymer reduce one or more of these properties. It is true that a wide variety of acrylic copolymers are used to make excellent lacquers for many purposes, but in discussing acrylic lacquers we will now confine our attention to lacquers of polymethyl methacrylate. 

Clear organic coatings have been developed to preserve the attractive, bright, as-polished, zinc, zinc alloy, or zinc-coated surfaces. The coatings may be either acrylic or polyurethane lacquers or polyester powders and may be colorless or tinted, usually to simulate brass. They usually incorporate ultraviolet absorbers and a complexing agent for zinc (dithiooxamide). They have only a limited life and, in the atmosphere, usually must be renewed after 3-10 years (depending on the environment) to retain appearance. 

Dipropylene glycol diacrylate from ultraviolet-cured lacquer... 

Ultraviolet-curable inks and lacquers (acrylate-based) 0.01-0.1% pet. 

Under pressure, these Thiokol rubbers distort, although Thiokol ST is superior to FA. However, they are resistant to petroleum solvents, esters and ketones, aromatic fuels, oils, greases and lacquer thinners, ozone, sunlight and ultraviolet light. This makes them very useful for static seals where no other material will serve. 

Ultraviolet light-hardenable pigmented alkyd resin lacquer preparations [95]. 

In automotive finish coats, the alkyd-aminoplast resin enamels had better initial luster than cellulose nitrate lacquers, and greater resistance to road-tar stain and to chalking or exterior exposure, particularly in the areas receiving much ultraviolet light. The relative advantages, however, varied greatly from one pigment to another. 

The oriental lacquer is prepared from the sap of the varnish tree" Rhus verni-ciflua, which is an emulsion of an aqueous phase and an organic phase called urushi-ol. The urushi fraction consists of a mixture of catechol derivatives substituted in 3-po-sition with aliphatic C- 5 or C- 7 side chains. About 60% of these side chains are trie-nes. The structure of the trienes is similar to that in linseed or tung oil and is essential for the effectiveness of the oxidative curing of oriental lacquer. We have utilized new techniques and used combinations of modern techniques to analyze the urushiol mixtures and to characterize and identify each individual compound. We have also developed ultraviolet stabilizers for oriental lacquer, stabilizers that could be incorporated into the polymerizing mixture during the curing process to result in ultraviolet stabilized oriental lacquer. 

Polymerizable surfactants can be used to modify surfaces by polymerization of the adsorbed surfactant by ultraviolet (UV) irradiation. A surface of a paint film or lacquer can be fluorinated by cross linking a polymerizable fluorinated surfactant which has migrated to the surface and formed a monolayer [231]. 

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