Bakelite varnishes are the solutions of pitches on spirit basis made by means of condensation of phenol and formaldehyde. As the catalyst in chemical reaction in this case ammonia which gives to varnishes specific smell acts.
Bakelite varnishes are used for covering of various surfaces, their main destination is protection of the equipment against influence agre6ssivnoy service water, weak and strong acids. Also such varnishes are applied to painting of gasoline tanks and as the connecting means for layered plastics. Unlike many analogs, bakelite varnish can be used for impregnation and even pasting of parts of products from high-adhesive materials.
Varnish production
For preparation of bakelite varnish phenol, formalin, ammonia water and ethanol are used. Phenol is organic compound which is completely dissolved in water and stiffens at temperature above 40o S. Formalin – transparent liquid with small degree of reactivity, phenol is considered poison. The ammonia water is 20% water solution of ammonia. Ethyl alcohol or ethanol - colourless easily mobile liquid, product of distillation of carbon-bearing products. As a result both the red, and brown shade turns out to have transparent solution which can be.
Storage life of such varnish should not exceed three months from the date of its production.
Types of varnishes
Bakelite varnishes happen various grades: - LBS-1 and LBS-2 (premium), - LBS-4, - LBS-5, - SBS-1, - LBS-8, - LBS-16, - LBS-20 and LBS-29. Depending on the brand the percentage of above-mentioned substances in bakelite varnish varies. As a result its properties and functions change. So, for example, LBS-4 varnish is used for production of plastic with mineral fillers, and SBS-1 for production of wood-fiber plastics and plywood. The main task of bakelite varnish is creation of thin protective film which can consist of inorganic and of organic polymers. Such film does not change color of surface, hides roughnesses and interferes with moisture penetration in product. Feature of such varnish is the vegetable oil which is its part. Also cellulose which is processed previously is part of bakelite varnish.
Properties of bakelite varnish will not change if to add dye to it therefore it is possible to find right color of varnish easily.
Use of bakelite varnish in house conditions is complicated by the fact that after putting varnish on clean and dry surface it needs to be subjected to heat treatment, gradually increasing temperature to 160 wasps. As a result (in 20 seconds) the plastic film which will serve long time will turn out if surrounding temperature is not higher than 20 wasps and also direct impact of sunshine will be excluded.