Nitrocellulose lacquer

With these lacquers, nitrocellulose-based primer-surfacers are used. As well as liquid plasticisers, a wide range of materials are used as plasticising resins short oil alkyds, maleinised oils, ester gum, rosin and bodied castor oils. Pigmentation is usually inert. Thermoplastic acrylics are often preferred under acrylic lacquers these are based on acrylic resins and cellulose acetate butyrate. 

Cellulosic raw materials. Linters or wood pulp cellulose are in use as raw material for manufacturing lacquer nitrocellulose. It is essential to use very well purified and bleached raw material. Wood cellulose should contain mainly a-cellulose. The admissible pentosan content is limited to traces only, because these compounds are a source of products insoluble in organic solvents. Cellophane can also be utilized for nitration. 

An essential, important test is the measurement of the viscosity of a cupram-monium solution of the cellulose, as by this method it is possible to classify cellulosic material into grades suitable for manufacturing lacquer nitrocellulose of the desired viscosity. 

Stabilization. After being thoroughly washed free from acid, the nitrocellulose is subjected to stabilization-either in boilers and afterwards in autoclaves (Fig. 153), or directly in autoclaves. Pressure boiling nitrocellulose in autoclaves makes it possible to control the viscosity of nitrocellulose with a high accuracy, since both time and temperature are controlled. The kiers for lacquer nitrocellulose manufacture are... 

A considerable advance in the practice of stabilizing lacquer nitrocellulose was made by the development of a continuous process of boiling under pressure in acid-resisting tubes, 100 mm dia., up to 1500 m long (Figs. 164 and 165), The tubes are warmed or cooled by means of outer jackets being heated throughout... 

Great attention should be paid during the manufacture of lacquer nitrocellulose to the purity of the water used for washing and stabilization. The water should be carefully freed from iron, the maximum permissible concentration of which is 0.002 g/1. Water used in the production of film nitrocellulose should be of even higher purity and also must not contain calcium salts. 

Bleaching. It is often necessary in the manufacture of lacquer nitrocellulose to remove all traces of coloured substances by bleaching. One method consists in oxidizing with potassium permanganate in the proportion of 1 kg KMn04 to 100 kg of lacquer nitrocellulose in the presence of a little sulphuric acid. After the reaction is over the nitrocellulose is rinsed with water, and the brown colour of manganese dioxide is removed by the action of sulphur dioxide or sodium sulphite. 

Synonyms nitrocellulose-alkyd lacquers nitrocellulose vinyl resins acrylic resins Lactated Mono-Diglycerides... 

Uses Plasticizer for heat-seal applies., food wrappers/labels, pharmaceutical labels, foil lacquers, cellophane lacquers, nitrocellulose, eth-ylcellulose, chlorinated rubber, PVAc, PVC, food-contact polymers, printing Inks for paper/vinyl/textiles In food-pkg. adhesives In paper/ paperboard In contact with aq./fatty foods In cellophane for food pkg. Regulatory FDA 21 CFR 175.105,176,170,176.180,177.1200,178.3740 ManuUDistrib. Aldrich Alfa Chem Bayer ChemServIce Morflex P.A.T. Prods. Schwelzerhall Unitex... 

Toxicology ACGIH TLV/TWA 50 ppm LD50 (oral, rat) 4760 mg/kg, (IP, rat) 400 mg/kg, (skin, rabbit) 10 g/kg mod. toxic by ing. and IP routes mildly toxic by inh., skin contact TSCA listed Precaution Flamm. exposed to heat, flame, oxidizers Hazardous Decomp. Prods. CO, CO healed to decomp., emits acrid smoke and irritating fumes NFPA Health 1, Flammability 2, Reactivity 0 Uses High-boiling solvent for paints, lacquers, nitrocellulose, cellulose acetate butyrate, acrylics, and vinyl copolymers ManufJDisttib. Aldrich Allchem Ind. Ashland Burdick Jackson ... 

Uses modifier and adhesion promotor for film-forming natural and synthetic resins in vinyl lacquers, nitrocellulose compositions (nail lacquers), polyvinyl alcohol adhesives, acrylics. TOSYLAMIDE/FORMALDEHYDE RESIN... 

Different additives are added to nail lacquers in order to fulfil the aforementioned cosmetic and technical qualities. For example, film formers are added, which are ingredients of the film that determine the principal cosmetic quality of the lacquer (nitrocellulose plasticizers such as dibutyl phthalate, camphor and citric acid esters resins). 

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