Aqueous nitrocellulose lacquers

Aqueous nitrocellulose lacquers that contain small amounts of solvent are used in the form of emulsions or dispersions to coat leather [2.4] and decorative foils. Solvent-free dispersions are cured by UV radiation after evaporation of the water and are used to coat furniture, profiled boards, and paper. 

Cellulose nitrates (Celluloid) may be recognized by the above reactions and by the sensitive diphenylamine test. Heat a sample with 0.5 N aqueous potassium hydroxide (2.8 g potassium hydroxide in 100 ml water) or 0.5 N sodium hydroxide (2.0 g NaOH in 100 ml water) for a few minutes and then acidify this with dilute sulfuric acid. Separate the supernatant liquid from the residue. Layer a solution of 10 mg diphenylamine in 10 ml concentrated sulfuric acid on top of that. A blue ring at the interface indicates cellulose nitrate. In order to identify nitrocellulose lacquers on cellophane, dissolve a few crystals of diphenylamine in 0.5 ml concentrated sulfuric acid and add a few drops of this to the sample. A blue color is a positive test. 

Acrylic (Thermoplastic) Car finishing and refinishing. Lacquers for PVC leathercloth Ketones Esters Aromatic hydrocarbons Aliphatic hydrocarbons Alcohols Diluents are normally present at much lower concentrations than for example, in nitrocellulose lacquers. Thermoplastic acrylics may also be used in the form of non-aqueous dispersions, in which case the solvent blend will contain a high proportion of aliphatic hydrocarbons. 

The non-thermoplastic casein binder ensures processability in the wiping process by reducing sensitivity to heat and improving hot rub resistance. Useful top coats include a nitrocellulose lacquer or an aqueous system with a very hard and hence plating-fast polyurethane dispersion. If necessary, the latter can be crosslinked to improve the rubfastness. 

Isopropyl ocetote is a wofer-whife pleosont-odored liquid with properties intermediote between ethyl and butyl acetates. It is miscible with most of the common organic solvents such os alcohols, ketones, esters, oils, hydrocarbons, etc., and it is a solvent for nitrocellulose, cellulose ocetate (of low viscosity) and a wide ronge of oils, fats, waxes, gums ond notural and synthetic resins. Like n-propyl ocetote, its solvent power for cellulose esters is increosed when lower aliphatic alcohols are added. It is largely used in the lacquer industry where its slow evaporation rate and blush resistance ore of importance. It is also used in the monufacture of plastics, artificial leather, dopes, films, cements, and in the recovery of acetic ocid from aqueous solutions. 

Lacquer (topcoats) A solution of organics in a solvent that crosslink and form a film when the solvent is evaporated. In early 1900s terminology, the solid material was nitrocellulose-based and the solvent was non-aqueous. In newer uses of the term, the solid can also be a thermoplastic material, such as a vinyl or an acrylic, or thermosetting materials, such as epoxies and phenolics, and the solvent can be water. 

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