METHOD OF PROCESSING SKIN OF LAKE FROG Russian patent published in 2015 - IPC C14C13/00 

FIELD: chemistry.

SUBSTANCE: method of processing lake frog includes soak, fleshing, degreasing, fermentative processing, degreasing, washing, liming, partial de-ashing, softening, pickling, tanning, neutralisation, after-tanning, decoration operations. First fermentative processing of frog skin is realised by preparations Pectophoetidin G20x with concentration 2.0-2.5 g/dm³, Celloviridin G20x with concentration 2.0-2.5 g/dm³ and Protosubtilin G3x with concentration 2.2-2.7 g/dm³ with the total liquid coefficient 1.6 and temperature 32°C in drum in rotation-stop mode for respectively 5 and 30 min for 90 min. Second fermentative processing - properly softening is carried out after the process of liming with application of Ca(OH)₂ with concentration 10.0-13.0 g/dm³ and Na₂S with concentration 1.5-2.5 g/dm³ and partial de-ashing to pH=9.0 by proteolytic enzymes: alkaline protease Protosubtilin G3x with concentration 2.0-3.0 g/dm³ for 90 min. Tanning is realised in three stages: at first with potash alums with concentration 10.0-15.0 g/dm³, then by chrome tanning agent with concentration 10.0-13.0 g/dm³ and after laying and neutralisation with Na₂CO₃ with concentration 4.2-4.9 g/dm³ after tanning is carried out with syntan "Basyntan" with concentration 10.0-18.0 g/dm³.

EFFECT: method of processing improves physical-mechanical characteristics of frog skin to a considerable extent.

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