METHOD OF FORMING LIGHT-ABSORBING COATING Russian patent published in 2024 - IPC C25D5/24 C25D5/50 G02B1/115 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of forming a light-absorbing coating. Nickel-phosphorus film is deposited by electroplating at current density of up to 30 A/dm² from an electrolyte solution consisting of 0.9-1.1 mol/l nickel sulphate hexahydrate, sodium phosphate 0.2-0.3 mol/l, carboxylic acid in the form of acetic acid 0.2-0.3 mol/l and dicarboxylic acid in form of succinic acid 0.1-0.2 mol/l, at working acidity of electrolyte of 4.5-5 pH and electrolyte temperature of 85-90 °C. Electroplated nickel-phosphorus film is subjected to thermal treatment at temperature from 200 to 250 °C and oxidised in a solution of sulphuric acid and sodium nitrate at temperature of 70-80 °C.

EFFECT: high efficiency of forming a light-absorbing coating.

1 cl, 1 ex