The plane mirror is made by electroless silver plating, and a silver film is deposited on the surface of the flat glass. Its chemical principle is that silver ions in the reduction of organic matter under the action of metal silver crystal precipitation. In order to obtain a fine silver film, you must control the silver precipitation and deposition rate. The mirror of the ordinary mirror is silver and white. When making a mirror, a small amount of silver (translucent) is precipitated on the mirror, and then coated with a layer of colored paint on the silver film to obtain a colored mirror. Use a transparent colored flat glass for the usual silver mirror reaction, can get another color mirror.
(1) preparation of silver ammonia solution in 5% silver nitrate solution by adding concentrated ammonia water, until the precipitation began to disappear. And then dropping 10% sodium hydroxide solution (per milliliter of silver nitrate plus a drop of sodium hydroxide solution), and then drop by adding concentrated ammonia, until the precipitation disappeared again. Then silver nitrate solution back to the solution slightly turbid so far. Finally add 2 times the volume of distilled water diluted. Such as the use of dilute solution of peach dilution, made of color mirror better quality. (2) Color and transparent polyurethane preparation Take xylene and cyclohexanone in 1: 4 volume ratio as a solvent mixture. Weigh the solvent quality of 1/20 of the transparent pigment added to the solvent, stirring, until completely dissolved up. The resulting transparent pigment solution was slowly added to the polyurethane (trade name: water 685, is a varnish), while stirring side, until the color to meet the requirements so far.
Method one: you can use the market to buy blue or brown, red glass sheet processed into a color mirror. (1) with a soft cotton cloth dipped in detergent repeatedly scrub the glass plate, and then rinse with water. Wipe with some soft red powder (iron oxide powder) on the glass plate repeatedly scrub, completely remove the surface of the dirt and greasy, and finally rinse with water until no red iron red powder remaining, the glass surface of the water Membrane evenly, do not hang water drops. (2) rinse with stannous chloride solution 2 to 3 times, so that the glass plate to silver areas are infiltrated to make its surface sensitized. And then rinse with distilled water 2 to 3 times to remove chloride ions. Place the cleaned flat glass on the table or other bracket so that the glass is level and suck off the water droplets hanging on the edge, but can not touch the clean face again. (3) Mix the silver ammonia solution with 4% sodium tartrate in a 1: 1 by volume ratio and immediately lean on the glass (no sodium potassium tartrate, which can be replaced with 0.2 mol / L glucose solution). The amount of the mixed solution can be calculated according to the area of the mirror, generally about 30mL per square meter of the mixture. The mixture is filled with glass and accumulated to a certain thickness. (4) standing for about 10 minutes (time with room temperature, the higher the room temperature, the shorter the time), dumping the remaining test solution on the glass, and then a small flow of water carefully washed with silver particles on the surface. Then press the operation (3) method, repeat the operation 1 or 2 times. (5) pick up the glass, look at the place where there is light, if the glass plate is no transparent shape can be. (6) with a small flow of water carefully to the glass surface of the residual liquid. And then make the mirror dry (must be completely dry), and finally with a soft brush dipped in xylene diluted polyurethane glue carefully coated on the silver surface, until it is dry, you can also layer a layer of red paint, as a silver mirror protection Floor.
Method 2: The use of ordinary colorless glass color mirror (1) ~ (4) operation with the same method. (5) pick up the glass to the place where there is light, if the silver surface is painted evenly, complete, and make the glass was translucent. And then carefully cleaned and dried by the above method. (6) with a soft brush to the front with a good color transparent polyurethane evenly coated on the silver surface, after drying Serve.
(1) decided to mirror the quality of the factors in addition to the ratio of mixed liquid, the most important thing is the glass cleaning, as long as the glass clean and smooth, it will be able to make bright, uniform silver mirror. (2) clean the glass surface can not touch with your fingers, fingers touch the place is not easy to apply silver surface. (3) glass placed to maintain the level, so you can ensure uniform distribution of silver plating. (4) If the room temperature is too low (winter), can be slightly heated with hair dryer. (5) in the coating of polyurethane or colored transparent polyurethane, silver must be dry, or easy to fall off the silver side. (6) The silver ammonia solution can not be stored for a long time to prevent the conversion to silver (AgONC) or silver azide (AgN3). After the reaction of the mixed solution to be timely treatment, can not be stored. (7) silver ammonia solution and potassium tartrate solution mixed, the silver began to precipitate, so the operation should be calculated when the amount of mixed solution, with how much to prepare how much, so as to avoid waste.